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Athletes are under immense pressure. Athletes feel the pressure to perform their best to win, attain coveted scholarships, be selected in a draft, and even to look a certain way (i.e. achieve perfection). As we’ve seen within the sporting culture, this pressure can compel athletes to engage in tactics that may improve their chances in sport, but can be detrimental to their overall health.

Athletes may use drugs to deal with the mounting pressure they feel to succeed. Lance Armstrong used in the Tour de France and Sha’Carri Richardson and Kamila Valieva used at the Olympics. Some athletes may resort to other behaviors that can have detrimental effects on both health and athletic performance, such as dieting, disordered eating, and binge eating. Let’s explore, in depth, the eating disorder prevalence in athletes, risk factors associated with these disorders, and important treatment considerations for all at-risk athletes.

 

Athletes may resort to behaviors that can have detrimental effects on health and athletic performance such as dieting, disordered eating, and binge eating.

 

Eating Disorders in Athletes
According to research, elite athletes are at higher risk for developing an eating disorder (ED) than the general population (Mancine et al., 2020; Martinsen & Sundgot-Borgen, 2013). This risk is high for youth and adolescent athletes, but these practices can also be carried into college. One study found that 32.5% of the collegiate female athletes had eating disorders (Canbolat & Cakiroglu, 2020). EDs that are developed during adolescence can even be carried into adulthood sport participation (Sundgot-Borgen, 1994). Unfortunately, these practices are not abandoned once the athletes “retire” from their sport, as ED may continue to appear within a retired athletes’ life (DeZiel & DeBeliso, 2020).

 

Elite athletes are at higher risk for developing an eating disorder (ED) than the general population.

 

ED are defined as “behavioral conditions characterized by severe and persistent disturbance in eating behaviors and associated distressing thoughts and emotions” (American Psychiatric Association, 2021). Whereas the prevalence of EDs in the general population is 5% (American Psychiatric Association, 2021), the prevalence is higher in athletes with 6-45% of female athletes suffering from this type of disorder (Bratland-Sanda & Sundgot-Borgen, 2013). Male athletes have a higher rate of ED compared to male non-athletes as well (Karrer et al., 2020).

 

Why (i.e., Risk Factors)
Why are athletes at greater risk for ED than the general population? They embody certain personality characteristics that put them at risk for developing an ED. For example, perfectionism, achievement motivation, and competitiveness are necessary traits for improvement in one’s sport. These same characteristics, especially perfectionism, make athletes vulnerable to developing disordered eating (Prnjak et al., 2019). Female athletes are at a greater risk for developing ED than male athletes.

 

Perfectionism is the greatest risk factor for disordered eating among female athletes.

 

The type of sport that females participate in might also increase their risk of developing an ED. Gymnastics and figure skating emphasize leanness, flexibility and balance; cross country running emphasizes low body weight and percentage body fat. The female athletes who compete in any of these sports may be at higher risk for developing disordered eating or obsessive dieting as compared to athletes who compete in a sport like soccer (de Oliveira et al., 2017). This may be due to the notion that being thin in these sports leads to greater success (Aleksic Veljkovic et al., 2020). According to UK Sport, the sports with the highest risk of ED for both female and male athletes are swimming, running, gymnastics, diving, synchronized swimming, wrestling, judo, and lightweight rowing (Bashforth, 2022).

 

The type of sport that females participate in might also increase their risk of developing an ED.

 

There are several risk factors relating to this idea of thinness equals success. It can depend on whether or not someone else is “judging” their performance (as in a gymnastics routine), whether or not there is a competitive advantage in having a smaller body mass for the sport, dominant aesthetic patterns, and the size of the uniforms used in competition (Aleksic Veljkovic et al., 2020).

Some argue that the sporting environment may actually encourage or normalize these disorders through certain usual and customary practices. Daily or weekly weigh-ins or weight-monitoring practices that are common in sports, such as wrestling, may promote an over-fixation on weight which can result in EDs (Bashforth, 2022). Athletes are also encouraged to remain “healthy” and adhere to strict diet and training practices, which may also cause an over-fixation on eating behaviors. Some athletes such as Olympic diver Tom Daley have explained that a drive for thinness or the pressure to achieve a lower weight was “hammered into him” in order to perform optimally (Bashforth, 2022).

 

Consequences of ED in Athletes
ED are serious conditions that can have severe detrimental effects on one’s physical and mental health. The term “Female Athlete Triad” was previously used to explain the consequences of ED or disordered eating among female athletes. These consequences included loss of menstrual cycles (amenorrhea), and decreased levels of endogenous oestrogen and other hormones which together resulted in a loss of bone density and a higher risk for osteoporosis (Mountjoy et al., 2014).

 

The term “Female Athlete Triad” was previously used to explain the consequences of ED or disordered eating among female athletes.

 

It has since been recognized that the consequences of ED reach far beyond this “triad” and affect both male and female athletes with low energy availability. A new term called Relative Energy Deficit in Sport (RED-S) has been established to reflect these developments (Mountjoy et al., 2014).

 

Relative Energy Deficit in Sport (RED-S) has since replaced “Female Athlete Triad” to recognize that these consequences are broader than a “triad,” and that male athletes can be affected as well.

 

RED-S is a term used to describe the physiological consequences that are associated with athletes consuming too little calories for their activity levels (Mancine et al., 2020). These consequences can include: reduced hormone levels such as T3, insulin, leptin, and testosterone, and an increase in cortisol and cholesterol levels (Torstveit et al., 2018). More consequences include a disruption in menstrual cycles in females, impaired bone health, decreased resting metabolic rate, iron deficiency, impaired growth and development in adolescents, early atherosclerosis, impaired gastrointestinal functioning, and impaired immune system functioning (Mountjoy et al., 2018).

ED or RED-S can result in psychological challenges as well, including mood, anxiety, and substance abuse disorders (Mancine et al., 2020). It is important to note that while ED can result in psychological consequences, it can also be preceded by these factors as well (Mountjoy et al., 2014). For example, stress and depression might increase the risk of developing ED, but can also be a result of having low energy available (Mountjoy et al., 2014).

Athletes have much higher energy demands than nonathletes, so the consequences of low-calorie intake resulting from ED or disordered eating can be detrimental to both their health and athletic performance. The International Olympic Committee (IOC) releases regular consensus statements with recent developments, hoping to spread awareness of the risk factors, consequences, and treatment options for athletes who are suffering from such disorders.

EDs have the highest fatality rate of any mental health disorder, regardless of whether someone is an athlete or not. The fatality rate is higher in men than women, and one in five people struggling with anorexia die by suicide (Markey, 2022).

 

In Conclusion
Eating disorders are just one piece of a larger picture of overall mental health concerns of athletes. This has been a hot topic lately, as we are seeing more elite athletes, like Simone Biles in the 2020 Summer Olympics, willing to open up about their own personal mental health challenges. Athletes may be at high risk for developing ED, along with other mental health disorders, due to the intense physical and mental demands placed on them, increased public scrutiny resulting from social media, team dynamics, and potential for injury (Rice et al., 2016).

The Nutritional Psychology Research Library Sport and Disordered Eating Research Category has been developed as a tool to help coaches, trainers, parents of youth athletes, and athletes themselves, to gain a better awareness of these disorders. This increased awareness, along with knowledge of the risk factors and treatment options available, will help those who work with athletes to gain a better understanding of the mental health challenges facing them. This insight can help to support their physical and mental well-being.

 

References
Aleksić Veljković, A., ĐUrović, D., Biro, F., Stojanović, K., & Ilić, P. (2020). Eating attitudes and body image concerns among female athletes from aesthetic sports. Annales Kinesiologiae, 3–16. https://doi.org/10.35469/ak.2020.242

American Psychiatric Association (2021). What Are Eating Disorders? https://www.psychiatry.org/patients-families/eating-disorders/what-are-eating-disorders

Bashforth, E. (2022, March 21). Eating disorders in athletes: how can we tackle them? Patient. https://patient.info/news-and-features/eating-disorders-in-sport-why-are-they-so-common-and-how-can-we-tackle-them

Bratland-Sanda, S., & Sundgot-Borgen, J. (2013). Eating disorders in athletes: Overview of prevalence, risk factors and recommendations for prevention and treatment. European Journal of Sport Science, 13(5), 499–508. https://doi.org/10.1080/17461391.2012.740504

Canbolat, E., & Cakiroglu, F. P. (2020). Eating Disorders and Nutritional Habits of Female University Athletes. Turkish Journal of Sports Medicine, 55(3), 231–238. https://doi.org/10.5152/tjsm.2020.181

de Oliveira, G. L., de Oliveria, T. A. P., de Pinho Goncalves, P. S., Silva, J. R. V., Fernandes, P. R., & Filho, J. F. (2017). Body Image and Eating Disorders in Female Athletes of Different Sports. Journal of Exercise Physiologyonline, 20(2).

DeZiel, J., & DeBeliso, M. (June 2020). Eating disorders in former NCAA division 1 collegiate gymnasts and their behaviors after graduating. Journal of Physical Education Research, 7(2), 35-44.

Karrer, Y., Haliousa, R., Mötteli, S., Iff, S., Seifritz, E., Jäger, M., Claussen, M.C. (2020). Disordered eating and eating disorders in male elite athletes: a scoping review. BMJ Open Sport & Exercise Medicine, 0. doi:10.1136/bmjsem-2020-000801

Mancine, R. P., Gusfa, D. W., Moshrefi, A., & Kennedy, S. F. (2020). Prevalence of disordered eating in athletes categorized by emphasis on leanness and activity type – a systematic review. Journal of Eating Disorders, 8(1). https://doi.org/10.1186/s40337-020-00323-2

Mancine, R., Kennedy, S., Stephan, P., & Ley, A. (2020). Disordered Eating and Eating Disorders in Adolescent Athletes. Spartan Medical Research Journal. https://doi.org/10.51894/001c.11595

Markey, C. (2022). Eating Disorders Affect Boys and Men Too. U.S. & World Report News. https://health.usnews.com/health-news/blogs/eat-run/articles/eating-disorders-and-body-image-issues-in-boys-and-men

Martisen, M., & Sundgot-Borgen, J. (2013). Higher Prevalence of Eating Disorders among Adolescent Elite Athletes than Controls. Medicine & Science in Sports & Exercise, 45(6), 1188–1197. https://doi.org/10.1249/mss.0b013e318281a939

Mountjoy, M., Sundgot-Borgen, J. K., Burke, L. M., Ackerman, K. E., Blauwet, C., Constantini, N., Lebrun, C., Lundy, B., Melin, A. K., Meyer, N. L., Sherman, R. T., Tenforde, A. S., Klungland Torstveit, M., & Budgett, R. (2018). IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. British Journal of Sports Medicine, 52(11), 687–697. https://doi.org/10.1136/bjsports-2018-099193

Mountjoy, M., Sundgot-Borgen, J., Burke, L., Carter, S., Constantini, N., Lebrun, C., Meyer, N., Sherman, R., Steffen, K., Budgett, R., & Ljungqvist, A. (2014). The IOC consensus statement: beyond the Female Athlete Triad—Relative Energy Deficiency in Sport (RED-S). British Journal of Sports Medicine, 48(7), 491–497. https://doi.org/10.1136/bjsports-2014-093502

Prnjak, K., Jukic, I., & Tufano, J. J. (2019b). Perfectionism, Body Satisfaction and Dieting in Athletes: The Role of Gender and Sport Type. Sports, 7(8), 181. https://doi.org/10.3390/sports7080181
Rice, S. M., Purcell, R., de Silva, S., Mawren, D., McGorry, P. D., & Parker, A. G. (2016). The Mental Health of Elite Athletes: A Narrative Systematic Review. Sports Medicine, 46(9), 1333–1353. https://doi.org/10.1007/s40279-016-0492-2

Sundgot-Borgen J. (1994). Risk and trigger factors for the development of eating disorders in female elite athletes. Medicine and science in sports and exercise, 26(4), 414–419.

Researchers continue to pursue a better understanding of how our food choices and eating behaviors are influenced by the subjective sensations we experience in relation to foods. In their 2020 study, Duerland and colleagues explored the relationship between subjective sensations and food choice.

In this study, 253 participants, ages 18-30 years, were recruited from a university in New Zealand. Participants were approached on campus, and the experiment occurred on site. They first answered background questions and indicated their degree of health consciousness by evaluating their level of agreement with the following statements: “I choose food carefully to ensure good health,” and “I think of myself as a health-conscious consumer.” Next, participants used a 0 (“not at all”) to 10 (“very much”) scale to rate their current experience of 13 food-related sensory-specific sensation variables: Energy, Concentration, Sleepiness, Fullness, Hunger, Overall Wellbeing, Physical Well-being, Mental Well-being, Desire-to-Eat, Desire-to-Snack, Sweet Desire, Salty Desire, and Fatty Desire (see Figure 1).

 

Figure 1. Thirteen food-related sensory-specific sensation variables (Duerlund, 2020)

 

Participants were then invited to choose a snack from six available options. The six snacks were divided into two categories, “healthy” and “unhealthy,” and encompassed sweet, salty, and fatty taste sensations. Grapes (sweet), nuts (salty), and dark chocolate (fatty) comprised the “healthy” options. “Unhealthy” snacks included jelly beans (sweet), potato chips (salty), and cookies (fatty). Participants’ snack choices were recorded.

Overall, grapes were chosen most often, and jellybeans the least. Sensory-specific sensations did impact snack-choice behavior. Sweet Desire, Salty Desire, and Fatty Desire demonstrated the greatest effects. Specifically, higher ratings of Salty Desire and Fatty Desire led to an increased likelihood of selecting potato chips. High Sweet Desire was associated with choosing dark chocolate. Other sensations found to impact snack choice included Hunger, Physical Well-Being, Desire-to Eat, and Desire-to-Snack. 

 

Figure 2. Sensory-Specific Sensations and Snack Choice (Duerlund, 2020)

 

Background information also affected snack choice, which the authors explain is indicative of the multitude of factors contributing to food-selection behavior. In this study, high health consciousness and female gender drove the selection of “healthy” snacks, while the male gender was most associated with the “unhealthy” choices. 

These findings provide new insights into how subjective sensations, health consciousness, and even gender can impact snack choice, which the authors note could contribute to a better understanding of public health issues, such as unhealthy snacking and obesity.  

Editor’s Note:

While it is important to know more about people’s food choice behavior in relation to their sensations, several aspects should be taken into consideration when reading this study and its study design. Taste is one of the major contributors when it comes to a food choice (e.g., Diószegi et al., 2019) and could have influenced the results of this study; jellybeans are a good example for this as it is either liked or rather disliked by people compared to a more “neutral” food such as grapes. Thus, choosing food is also related to taste preference. Another aspect is the timing of the study. The study was conducted between 8 am and 4 pm which could have influenced food choice behavior since situational appropriateness impacts people’s food preferences (Cardello et al., 2000). The desire to eat jellybeans at 8 am might differ drastically from the desire to eat them at 3 pm, while this might not be the case for cookies or nuts. Both aspects could have been taken into consideration when conducting and analyzing this study. However, despite these limitations, the study provides an important contribution to the literature on the influence of sensations on food choice behavior. 

References: 

Cardello, A.V., Schutz, H.G., & Snow, C. (2000). Predictors of food acceptance, consumption and satisfaction in specific eating situations. Food Quality and Preferences, 11(3), 201-216. https://doi.org/10.1016/S0950-3293(99)00055-5

Duerland, M., Andersen, B.V., Alexi, N., Peng, M., & Byrne, D.V. (2020). Subjective sensations related to food as determinants of snack choice. Foods, 9(3): 336. https://doi.org/10.3390/foods9030336

Diószegi, J., Llanaj, E., & & Ádány, R. (2019). Genetic background of taste perception, taste preferences, and its nutritional implications: A systematic review. Frontiers in Genetics, 10, 1272. https://doi.org/10.3389/fgene.2019.01272

Adolescents seem to be vulnerable to feeling dissatisfied with their weight and body shape (Clay et al., 2005). Their perception of their body image (i.e., their Diet-Perceptual Relationship) may be shaped by the opinions of their family and friends; what they see in television, movies, and magazines (Silva et al. 2021); and all forms of social media (i.e., their Diet-Psychosocial Relationship). At the same time, it’s crucial that adolescents develop a healthy body image since it can affect mental and physical health — especially if their perception differs from their actual weight and nutritional status.

 

There is emerging evidence of a connection between body perception and diet.

 

There is emerging evidence of a connection between body perception and diet. For instance, researchers have found that Greek adolescents were less likely to be overweight or obese if they accurately guessed their weight status and adhered closely to a “healthy foods” dietary pattern, compared to those who followed a diet consisting of unhealthy/high-fat or starchy, protein-rich foods (Kanellopoulou et al., 2021). Unsurprisingly, many research papers have suggested that certain dietary patterns (typically those labeled “healthy” and/or “traditional”) can protect people against being obese/overweight. 

Based on such findings, it’s purported that an accurate perception of one’s weight in conjunction with healthy dietary intake habits may play into obesity prevention strategies. Let’s take a closer look at a cross-sectional research study on this topic by Silva et al. (2021), which examined the relationship between weight misperception and dietary patterns among Brazilian adolescents. 

 

Accurate weight perception in conjunction with healthy dietary habits could help prevent obesity.

 

For this study, the researchers recruited Brazilian teenagers from urban and rural schools in cities with populations larger than 100,000 across Brazil. Only adolescents deemed to be of normal weight were included. Their height and weight were measured and used to calculate their body mass index (BMI), and in turn their nutritional status (BMI relative to age). 

Next, the researchers assessed the participants’ perception of their own weight. The students were asked questions such as “Are you satisfied with your weight?” and “In your opinion, at what level is your current weight?” If they indicated feeling “not satisfied” and “below the ideal” regarding their weight, they were placed in the underestimation group. Those who answered “not satisfied” and “above the ideal” or “far above the ideal” were assigned to the overestimation group. The participants in these groups were considered to experience weight misperception. To understand the subject further, their dietary intake patterns were examined using 24-hour dietary recalls.

       

34% of the study sample (over 52,000 normal-weight adolescents) misjudged their own weight.

 

The data showed that 34% of the 52,038 normal-weight adolescents in Brazil misjudged their own weight, with higher incidence rates reported in girls (42.6%) than boys (25.6%). In addition, a higher proportion of girls perceived themselves as heavier than they actually were (weight overestimation) compared to boys (25.7% vs. 8.2%). The authors theorized that this higher prevalence of weight overestimation in girls could be attributed to gendered social constructs — in this case, perhaps the expectation of achieving a “perfect” body. While girls tend to overestimate their weight, boys are more likely to describe themselves as too thin (Park, 2011). Nowadays many young people are concerned about their body shape and size due to social pressures to conform to a thin, ideal body (Yan et al., 2018).

 

The higher incidence of weight overestimation in girls may be connected to the idea of a “perfect” body.

 

In this study, the female students showing weight overestimation were less likely to follow the “processed meat, sandwiches, and coffee,” “ultra-processed and sweet foods,” and “traditional Brazilian” dietary patterns (the latter is characterized by rice, beans, vegetables, and meat). This suggests a sense of apprehension towards eating — of restriction. A different study in South Korea demonstrated that girls with weight overestimation tend to have poor eating habits and employ unhealthy dieting methods to lose weight (Lim et al. 2014). In short, normal-weight adolescents who perceive themselves as overweight seem to put effort into losing weight — intentions that do not exactly translate into healthy weight loss behaviors. 

Similar to the girls, the normal-weight boys with weight overestimation were less inclined to adhere to a “traditional Brazilian” dietary pattern. As noted above, this “traditional” diet consists of several unprocessed or minimally processed foods, which are recommended by the Food Guide for the Brazilian Population. Worth mentioning is that this dietary guide does not recommend the intake of ultra-processed foods, warning Brazilians to avoid several of these food items found in the “ultra-processed and sweet foods” dietary pattern.  

For girls who underestimated their weight, the “ultra-processed and sweet foods” and the “traditional Brazilian” dietary patterns were more likely to be adopted. In boys, weight underestimation was directly associated with greater adherence to the “processed meat, sandwiches, and coffee” and “ultra-processed and sweet foods” dietary patterns. 

 

Weight underestimation showed correlations with the “ultra-processed and sweet foods” dietary pattern in both sexes.

 

Weight underestimation showed correlations with the “ultra-processed and sweet foods” dietary pattern in both sexes. Coupled with the association between weight overestimation and lower adherence to the “traditional Brazilian” dietary pattern, these results highlight that weight misperception is related to unhealthy eating habits among adolescents. 

Awareness of the adolescent Diet-Perceptual Relationship in children and adolescents can be an important element for policymakers in developing and implementing intervention programs to support accurate self-perceptions of body weight. Successful efforts on this front could contribute to the adoption of better eating habits and enhanced overall general health in youth. 

 

References

Clay, D., Vignoles, V.L. and Dittmar, H. (2005), Body image and self-esteem among adolescent girls: testing the influence of sociocultural factors. Journal of Research on Adolescence, 15: 451-477. https://doi.org/10.1111/j.1532-7795.2005.00107.x

Cuypers, K., Kvaløy, K., Bratberg, G., Midthjell, K., Holmen, J., & Holmen, T. L. (2012). Being normal weight but feeling overweight in adolescence may affect weight development into young adulthood-an 11-year followup: the HUNT Study, Norway. Journal of obesity, 2012, 601872. https://doi.org/10.1155/2012/601872

Lim, H., Lee, H. J., Park, S., Kim, C. I., Joh, H. K., & Oh, S. W. (2014). Weight misperception and its association with dieting methods and eating behaviors in South Korean adolescents. Nutrition research and practice, 8(2), 213–219. https://doi.org/10.4162/nrp.2014.8.2.213

Park, E. (2011). Overestimation and underestimation: adolescents’ weight perception in comparison to BMI-based weight status and how it varies across socio-demographic factors. The Journal of school health. 81. 57-64. 10.1111/j.1746-1561.2010.00561.x.

Silva, S., Alves, M. A., Vasconcelos, F., Gonçalves, V., Barufaldi, L. A., & Carvalho, K. (2021). Association between body weight misperception and dietary patterns in Brazilian adolescents: A cross-sectional study using ERICA data. PloS one, 16(9), e0257603. https://doi.org/10.1371/journal.pone.0257603

Yan, H., Wu, Y., Oniffrey, T., Brinkley, J., Zhang, R., Zhang, X., Wang, Y., Chen, G., Li, R., & Moore, J. B. (2018). Body Weight Misperception and Its Association with Unhealthy Eating Behaviors among Adolescents in China. International journal of environmental research and public health, 15(5), 936. https://doi.org/10.3390/ijerph15050936

 

 

For hundreds of years, scientists have suspected a connection between our personality traits and taste preferences. Anton Brillat-Savarin, the famous French gastronome, is quoted saying, “Tell me what you eat, and I will tell you who you are.” 

 

Tell me what you eat, and I will tell you who you are.

 

But what influences what we eat? It turns out that a symphony of elements influences our dietary intake patterns. These elements include (but are not limited to) our psychological traits (and mood states), cognitive and perceptual processes, behavioral attributes, psychosocial (including cultural) environment, and interoceptive experience. Each of these elements, in turn, is driven by physiological, biological, neuropsychological, and environmental states that are constantly at play within us (figure 1) (see the Nutritional Psychology Research Library).

Figure 1. Elements of the diet-mental health relationship (DMHR) informing nutritional psychology (NP)

 

Understanding the diet-mental health relationship (DMHR) involves a wealth of conceptual complexity. The burgeoning field of nutritional psychology is attempting to integrate this conceptual complexity into a singular infrastructure by which the conceptualization of the DMHR can grow (figure 1). Nutritional psychology involves understanding the myriad factors interconnecting our dietary intake with our psychological processes, functioning, and experience. A plethora of research exists (and is growing) to improve our understanding of these interconnections and is contained in the CNP Research Libraries. 

What is Guiding What We Eat?

On the surface, many of us believe that what we eat is guided by what we like and want to eat (or in the current dietary intake landscape additionally, what we crave to eat and what is available to eat). In fact, what we eat goes far deeper than simply wanting and liking certain foods. A host of involuntary factors, of which we are mostly unaware, influence our daily dietary intake including our perceptions and preferences, personality, mood, behavioral attributes, and even genetics (Neuroscientist News, 2022). Let’s begin by looking at taste perception, preference, and their connection with personality traits.

Genetic Basis for Taste Perception and its Connection with Personality Traits

Perceiving taste involves complex pathways that interface with multiple cranial nerves and areas in our brain. The five taste sensations (bitter, sweet, umami, sour, and salt) arise because of the activation of specific taste receptor cells on the lingual papillae on the tongue. Specific genes encode the different taste receptors. Varieties in these genes lead to the expression of different proteins associated with different tasting abilities, preferences, and personality traits. This serves as the genetic basis for taste and the perception of taste. 

Interestingly, sensory science divides people into supertasters, medium-tasters, and non-tasters. The TAS2R38 gene, located on chromosome 7, provides the genetic basis for taster status (Figure 2).  

Supertasters are defined as individuals with uncommonly low gustatory thresholds and strong responses to moderate concentrations of taste stimuli (Supertaster – APA Dictionary of Psychology, n.d.). Supertasters have an unusually high number of taste buds. This gene in supertasters increases their perception of bitter flavors in foods. 

 

Varieties in genes lead to the expression of different proteins associated with different tasting abilities, preferences, and personality traits.

 

For example, supertasters tend to find the taste of coffee to be very bitter. In relation to personality characteristics, studies have found that supertasters and medium-tasters tend to be more tense, apprehensive, and imaginative than non-tasters, while non-tasters are inclined to be more relaxed, placid, and practical (Mascie-Taylor et al., 1983).

Science also reveals a genetic basis for sweet liking, identified by a locus on chromosome 16 (Figure 2). Researchers divide the population into three categories related to the liking for sweetness: sweet-likers, sweet-neutral, and sweet dislikers. Regarding differences in the preferences for sweetness, studies have shown that these differences predicted intentions, prosocial personalities, and behaviors (Meier et al., 2012). 

Figure 2. The five taste sensations. The genetic basis for sweet liking is identified by chromosome 16, while chromosome 7 provides the genetic basis for taster status

 

It is important to note that in addition to our genes, our biochemical makeup also plays a role in our food perception and preference. For example, one study showed that salivary testosterone levels correlated with the amount of spice (Tabasco in this case) that participants chose to add to their food (Bègue et al., 2015). 

Now that we’re aware of the genetic (and biochemical) basis for taste perception and preference, and learned how our genes can influence personality, let’s look at how personality can influence food preference. 

Personality and Food Preference

Regarding food preferences, key factors of a person’s personality, including openness to experience (i.e., curiosity vs. caution), have been found to correlate with various aspects of food preference. For example, in a study by Conner et al. (2017), people with personality attributes like openness scored above average on preference for new food experiences. The controversy associated with such research, however, is that it has largely been conducted using self-rated food preferences, not in settings with actual food choices.

 

Key factors of a person’s personality have been found to correlate with aspects of food preference.

 

Many studies have addressed this issue. For example, a 2016 study analyzed participants’ willingness to try new foods. In this study, bite-sized pieces of twelve food items were placed in front of each participant (these included: octopus, hearts of palm, seaweed, soya bean milk, blood sausage, Chinese sweet rice cake, pickled watermelon rind, raw fish, quail egg, star fruit, sheep milk cheese, and black beans). Findings showed that the most anxious participants were the least willing to try new foods (Otis, 2016). This has been supported by other publications showing that anxious patients exhibit greater food aversions (Spence, 2021).

 

The most anxious participants were the least willing to try new foods.

 

Taste Perception and its Influence on Mood and Behavior

Now that we’ve explored some interconnections between genes, taste perception, and personality, let’s see how taste perception can influence our mood and behaviors. An example study by Vi and Obrist (2018) showed that those experiencing a sour taste were more likely engage in risk-taking. This was measured using the standardized Balloon Analogue Risk-Taking (BART) task, a computerized gambling task. Participants were asked to virtually pump up a balloon on a computer screen, with an accumulated monetary reward at stake. After each pump, the balloon either explodes or increases in size based on a randomized algorithm, yielding greater reward. Participants who had tasted something sour (as compared to a neutral water stimulus) were more likely to keep inflating the virtual balloon, risking the loss of the reward. 

A study exploring the interrelation between taste perception and mood (Chan et al., 2013) showed that tasting something sweet made people feel temporarily more romantic. And that by having people remember an episode of romantic love, they would report some foods as being sweeter than did those who were asked to recall a jealous memory. 

In another study by Ren et al., (2014), researchers exposed a group of participants to the sweet taste of Oreo cookies. This exposure resulted in a greater interest in initiating relationships with a potential partner. 

A study by Greimel et al., (2006) found that prompting people to remember being mistreated at work resulted in bitter tastes being rated as more intense, while watching a joyful film clip (compared to a sad movie clip) resulted in participants rating a sweet drink as more pleasant.

Taste Perception and Clinical Disorders

Some research on taste perception in the context of mental health shows that depressed patients have differences in perception of taste. While some studies have reported no difference in taste perception in depressed patients (Arrando, 2015; Nagai, et al., 2015), researchers Hur et al. (2018) found that the prevalence of altered smell and taste among patients with major depressive disorder was 39.8% and 23.7% respectively.

These changes in taste perception are hypothesized to be due to several mechanisms, but one mechanism seems to involve neurochemical changes that happen in our brain due to either emotional or pathological processes (e.g., depression leads to elevation of inflammatory cytokines like interleukin 6). These changes can result in actual changes in the gustatory system. 

It is hypothesized that changed taste thresholds could be attributed to reduced serotonin and noradrenaline levels in depressed patients, as suggested by Heath et al. (2006) (Figure 3). This proposed mechanism was supported by another study (Kim et al., 2017), which found reduced expression of 5‐HT1A receptors for serotonin in the taste cells of rats that developed anhedonia — a common symptom of depression. Case reports demonstrate that a change in taste is a neglected symptom in depressed patients that is worthy of further investigation (Miller & Naylor, 1989; Mizoguchi et al., 2012). 

Figure 3. Human gustatory pathway. Variations in serotonin levels are associated with different thresholds for certain tastes like bitter and sweet (Heath, 2006).

 

Research also shows that patients with panic disorders can have exhibited reduced sensitivity to bitterness (DeMet et al., 1989), while anxiety levels are positively correlated with the taste thresholds for bitterness and saltiness (Heath et al., 2006). 

According to Hur et al. (2018), it may be advisable for primary care providers to screen their patients for depression or other psychiatric conditions when they report changes in taste or smell.

Conclusion

In this article, we’ve had a little ‘taste’ of how our genes influence our taste perception and preferences. The DMHR plot thickens when we begin to be aware of how these perceptions and preferences can interplay with our personality, mood, and behaviors (figure 4).

Figure 4. Interconnections between genes, taste perception, and preference, behaviors, personality, and mood.

 

For example, we learned how anxious individuals can prefer a narrower range of food while people with personality attributes like openness typically score above average on preferences for new food experiences. Intriguingly, differences in food behavior and taste perception have been linked with circulating levels of certain neurotransmitters like serotonin and can affect taste perception in clinical disorders. 

While not lending to a conclusive understanding of the factors involved in dietary intake, our goal with this article is to provide you with a new awareness of the interconnection that occurs between your genes, personality, emotions, and food-related behaviors and preferences.  

To learn more, visit the CNP Diet and Personality and Diet and Sensory-Perception research categories in the NPRL. 

 

References

Arrondo, G., Murray, G. K., Hill, E., Szalma, B., Yathiraj, K., Denman, C., & Dudas, R. B. (2015). Hedonic and disgust taste perception in borderline personality disorder and depression. The British journal of psychiatry: the journal of mental science, 207(1), 79–80. https://doi.org/10.1192/bjp.bp.114.150433

Bègue, L., Bricout, V., Boudesseul, J., Shankland, R., & Duke, A. A. (2015). Some like it hot: Testosterone predicts laboratory eating behavior of spicy food. Physiology & Behavior, 139, 375–377. https://doi.org/10.1016/J.PHYSBEH.2014.11.061

Chan, K. Q., Tong, E. M. W., Tan, D. H., & Koh, A. H. Q. (2013). What do love and jealousy taste like? Emotion (Washington, D.C.), 13(6), 1142–1149. https://doi.org/10.1037/A0033758

Conner, T. S., Thompson, L. M., Knight, R. L., Flett, J. A. M., Richardson, A. C., & Brookie, K. L. (2017). The role of personality traits in young adult fruit and vegetable consumption. Frontiers in Psychology, 8(FEB). https://doi.org/10.3389/FPSYG.2017.00119

DeMet, E., Stein, M. K., Tran, C., Chicz-DeMet, A., Sangdahl, C., & Nelson, J. (1989). Caffeine taste test for panic disorder: Adenosine receptor supersensitivity. Psychiatry Research, 30(3), 231–242. https://doi.org/10.1016/0165-1781(89)90014-0

Greimel, E., Macht, M., Krumhuber, E., & Ellgring, H. (2006). Facial and affective reactions to tastes and their modulation by sadness and joy. Physiology & Behavior, 89(2), 261–269. https://doi.org/10.1016/J.PHYSBEH.2006.06.002

Heath, T. P., Melichar, J. K., Nutt, D. J., & Donaldson, L. F. (2006). Human taste thresholds are modulated by serotonin and noradrenaline. The Journal of Neuroscience, 26(49), 12664–12671. https://doi.org/10.1523/JNEUROSCI.3459-06.2006

Hur, K., Choi, J. S., Zheng, M., Shen, J., & Wrobel, B. (2018). Association of alterations in smell and taste with depression in older adults. Laryngoscope Investigative Otolaryngology, 3(2), 94–99. https://doi.org/10.1002/LIO2.142

Kim, D., Chung, S., Lee, S. H., Koo, J. H., Lee, J. H., & Jahng, J. W. (2017). Decreased expression of 5-HT1A in the circumvallate taste cells in an animal model of depression. Archives of Oral Biology, 76, 42–47. https://doi.org/10.1016/J.ARCHORALBIO.2017.01.005

Mascie-Taylor, C. G. N., McManus, I. C., MacLarnon, A. M., & Lanigan, P. M. (1983). The association between phenylthiocarbamide (PTC) tasting ability and psychometric variables. Behavior Genetics, 13(2), 191–196. https://doi.org/10.1007/BF01065667 

Meier, B. P., Moeller, S. K., Riemer-Peltz, M., & Robinson, M. D. (2012). Sweet taste preferences and experiences predict prosocial inferences, personalities, and behaviors. Journal of Personality and Social Psychology, 102(1), 163–174. https://doi.org/10.1037/A0025253

Mizoguchi, Y., Monji, A., & Yamada, S. (2012). Dysgeusia successfully treated with sertraline. The Journal of Neuropsychiatry and Clinical Neurosciences, 24(2). https://doi.org/10.1176/APPI.NEUROPSYCH.11040095

Nagai, M., Matsumoto, S., Endo, J., Sakamoto, R., & Wada, M. (2015). Sweet taste threshold for sucrose inversely 

Neuroscientist News. (2022, June 14). Do our genes determine what we eat? https://neurosciencenews.com/genetics-taste-perception-20833/

correlates with depression symptoms in female college students in the luteal phase. Physiology & behavior, 141, 92–96. https://doi.org/10.1016/j.physbeh.2015.01.003

Otis, L. P. (1984). Factors influencing the willingness to taste unusual foods. Psychological Reports, 54, 739–745.

Ren, D., Tan, K., Arriaga, X. B., & Chan, K. Q. (2014). Sweet love: The effects of sweet taste experience on romantic perceptions. Http://Dx.Doi.Org/10.1177/0265407514554512, 32(7), 905–921. https://doi.org/10.1177/0265407514554512

Smith, W., Powell, E. K., & Ross, S. (1955). Manifest anxiety and food aversions. Journal of Abnormal and Social Psychology, 50(1), 101–104. https://doi.org/10.1037/H0049253

Supertaster – APA dictionary of psychology. (n.d.). Retrieved January 28, 2022, from https://dictionary.apa.org/supertaster

Spence C. (2021). What is the link between personality and food behavior?. Current research in food science, 5, 19–27. https://doi.org/10.1016/j.crfs.2021.12.001

Vi, C. T., & Obrist, M. (2018). Sour promotes risk-taking: An investigation into the effect of taste on risk-taking behaviour in humans. Scientific Reports, 8(1). https://doi.org/10.1038/S41598-018-26164-3

 

Due to the aging world population, the number of people with cognitive impairment will have doubled by the year 2035. In addition, the number of individuals with cardiovascular disease (CVD) and Type-2 Diabetes Mellitus (T2DM) will increase substantially. Common denominators of these comorbidities are impaired vascular function and metabolic health. In this short article, we take a look at the connection between vascular health and cognitive function in the context of lifestyle factors, including nutrition. This connection is one of many within the diet-mental health relationship (DMHR), which nutritional psychology encompasses. The research discussed has been conducted by the Physiology of Human Nutrition (PHuN) research group in the Department of Nutrition and Movement Sciences at Maastricht University.

 

The number of people with cognitive impairment will double by 2035.

 

Compared to the wealth of knowledge on the effects of dietary factors on peripheral vascular function and the risk of CVD and T2DM, not much is known about the effects of diet on brain vascular and metabolic health, and cognitive performance. This is of utmost interest since the brain is one of the most metabolically active organs. Impaired brain metabolic health is associated with cognitive decline, while impaired brain vascular function is a major pathophysiological factor preceding the development of dementia. 

Although a healthy lifestyle protects against cognitive impairment, it’s not known whether these brain markers are sensitive to dietary interventions to prevent or slow cognitive impairment and the development of dementia. The specific assessment of brain metabolic health — especially in different cognitive-control brain areas — and brain vascular function is thus highly relevant (Figure 1).

Figure 1. Our research investigates the effects of dietary approaches on peripheral vascular and metabolic health, the risk of developing age-related conditions including CVD and T2DM, and the potential for dietary changes to improve brain health and cognitive performance (which can reduce the risk of dementia). 

Figure 2. Arterial Spin Labeling (ASL) cerebral blood flow (CBF) map in units of milliliters of blood per 100 grams of human brain tissue per minute (mL/100g tissue/min).

 

Methods

The research performed at the Physiology of Human Nutrition (PHuN) research group at the Department of Nutrition and Movement Sciences at Maastricht University involves well-defined nutritional intervention trials that are designed to assess the effects of diet on brain (vascular) health and cognitive performance. Intervention effects are studied using innovative and emerging non-invasive brain MRI methods based on Arterial Spin Labeling (ASL) perfusion contrast, which have provided means of probing metabolic effects in the brain, revealing brain metabolic health. Our findings show that cerebral blood flow (see Figure 2) can be considered a sensitive straightforward marker of brain vascular function, which strongly correlates with cognitive performance. 

Of note, lower cerebral blood flow is associated with accelerated cognitive decline and an increased risk of dementia in the general population. Cerebral blood flow is quantified by the non-invasive gold standard, which is the MRI perfusion technique pseudo-continuous ASL. In older adults, aging accounts for a decrease of about 0.45% to 0.50% in global cerebral blood flow per year. We therefore primarily focus on older men and women who are known to be at increased risk of cognitive impairment. 

 

Lower cerebral blood flow is associated with accelerated cognitive decline and an increased risk of dementia. 

 

Finally, cognitive performance is studied using the neuropsychological test battery CANTAB. These validated assessments for state-of-the-art cognitive performance testing focus on the main cognitive domains (i.e. attention, memory and executive function). 

 

Findings

In a published literature review (see reference 1), we have summarized the impact of dietary factors and exercise on brain vascular function in adults and discussed the relationship between these effects with changes in cognitive performance. We conclude that lifestyle factors, including diet and physical exercise, can improve brain vascular function which may contribute to the beneficial effects observed on cognitive performance. Indeed, in a recent study, we determined that aerobic exercise training improves regional cerebral blood flow in sedentary older men (2). These changes in cerebral blood flow may underlie exercise-induced beneficial effects on executive function. 

 

Diet and physical exercise can improve brain vascular function which may contribute to cognitive performance.

 

Recently, in another randomized, controlled crossover trial in older adults, the longer-term effects of soy nut consumption on brain vascular function and cognitive performance were investigated (3). We observed an increased regional cerebral blood flow following intake of soy nuts, which are not only rich in proteins but also in other potential bioactive ingredients. In fact, cerebral blood flow increased in four brain clusters located in the left occipital and temporal lobes, bilateral occipital lobe, right occipital and parietal lobes, and left frontal lobe which is part of the ventral network. These four regions are involved in psychomotor speed performance, which also improved as the movement time was reduced.

 

Relevance

The medical, psychosocial, and economic consequences of impaired cognitive performance in the context of the aging population will require multilevel assessments and multidimensional solutions. Effective dietary and evidence-based intervention and prevention strategies are therefore urgently needed. 

Beyond its scientific relevance, the outcomes of such research will contribute to other important areas. Dietary approaches, which can be implemented at relatively low costs by the aging world population, could scale down medical costs and therefore have significant societal and economic relevance. These studies are important from a consumers’ perspective as well as from an economic and public health point of view (e.g. health care costs, integrated dietary/lifestyle interventions, and dietary recommendations).

Empirical evidence on how nutrition interrelates with metabolic, vascular, and cognitive health supports our understanding of the DMHR as a whole and holds promise for future health-centric interventions. 

Visit the Diet and Aging and Diet and Brain Research Categories in the NPRL to learn more about how these factors interconnect. 

 

References

Joris, P. J., Mensink, R. P., Adam, T. C., & Liu, T. T. (2018). Cerebral blood flow measurements in adults: A review on the effects of dietary factors and exercise. Nutrients, 10. doi: 10.3390/nu10050530.

Kleinloog, J. P. D., Mensink, R. P., Ivanov, D., Adam, J. J., Uludag, K., & Joris, P.J. (2019). Aerobic exercise training improves cerebral blood flow and executive function: A randomized, controlled cross-over trial in sedentary older men. Frontiers in Aging Neuroscience, 11(333). doi: 10.3389/fnagi.2019.00333.

Kleinloog, J. P. D., Tischmann, L., Mensink, R. P., Adam, T. C., & Joris, P. J. (2021). Longer-term soy nut consumption improves cerebral blood flow and psychomotor speed: results of a randomized, controlled crossover trial in older men and women. The American Journal of Clinical Nutrition. doi: 10.1093/ajcn/nqab289.

 

This CNP Article is based on the findings from a recent study conducted by Lee, Eather, & Best, (2021).

The consumption of plant-based diets and the rate of depression have both risen within the last decade. While some studies have shown vegan and vegetarian diets to be conducive to mental health problems (e.g., Li et al., 2019), others claim that those who follow a plant-based diet experience higher levels of emotional health and well-being (Beezhold & Johnston, 2012). Still, others suggest that there is no relation (Lavallee, 2019). 

 

Could the lack of conversation around diet quality be cause for conflicting research?

 

Basically, the evidence on the relationship between plant-based dietary patterns and depression is inconsistent and conflicting. One possible explanation for this could be the lack of conversation around diet quality within the realm of plant-based diets. When we think of vegan and vegetarian diets, our brains may automatically conjure up images of health and vitality. And while such diets are associated with decreased risk of obesity, cardiovascular disease, type II diabetes, and other serious health issues, it’s important to discuss the different possible types of plant-based diets (Lee et al., 2021). 

A healthy plant-based dietary pattern is defined by a high intake of fruit, vegetables, nuts, seeds, legumes, whole grains, tofu, tempeh, and other minimally processed soy products. An unhealthy plant-based diet, on the other hand, would be characterized by high consumption of ultra-processed foods, high in fat and refined sugars. While decidedly low in nutrition, such diets can be vegetarian or vegan. You might know someone who falls into this trap — the friend who finds comfort in their decision to eat plant-based, only to consume french fries, donuts, highly processed plant-based meats, and other processed treats habitually. 

Noticing the inconsistency within current research when looking at plant-based diets and depression, researchers Lee et al. (2021) took to Facebook, Twitter, and Linkedin to survey the quality of vegans’ and vegetarians’ plant-based diets and their mental health. Of the participants surveyed, 165 self-identified as vegan and 54 as a vegetarian. The participants were aged 18–44, which is the same age group that is at the highest risk for depression (Australian Bureau of Statistics, 2019). The majority (93%) were female. Although this method of data collection and the study’s restricted sample limits our ability to draw sweeping conclusions, it nevertheless adds value to our understanding of the diet-mental health relationship. Let’s take a look at the measurement tools and findings. 

Depression rates of the participants during the week preceding the survey administration were measured using the 20-item Centre for Epidemiological Studies Depression (CESD) scale, with scores of 16 or higher suggesting greater symptoms of depression. Diet quality was assessed using an adapted version of The Dietary Screening Tool (DST), a 20-item questionnaire that asks participants to provide an estimated intake frequency of specific food categories. 

 

As diet quality increased, depressive symptoms decreased.

 

The researchers found that BMI was a significant contributor to the model. In other words, participants with higher depression scores had higher BMIs — a finding that could be a factor of diet quality. Using a multiple linear regression model, it was found that diet quality accounted for 6% of the variation in depressive symptoms, with BMI accounting for a further 3%. Overall, diet quality and BMI accounted for 9% of the variance in depression symptoms. And, notably, as diet quality increased, depressive symptoms decreased. 

With the heightened availability of processed vegan and vegetarian food products, the importance of understanding diet quality should not be understated. This is especially true when considering the rise of research demonstrating that lifestyle changes including diet and exercise have been shown to impact symptoms of depression (e.g., Jacka et al., 2017). In an era where certain diets have sky-rocketed in popularity, it’s worth discussing the quality of a diet as opposed to just its label. Only then can we be sure that the type of foods we are consuming is beneficial to both our physical and psychological health.

 

References:

Australian Bureau of Statistics. National health survey: first results, 2017-18 Canberra, act: Commonwealth of Australia, 2019. Available: https://www.abs.gov.au/AUSSTATS/abs@.nsf/Lookup/4364.0.55.001Main+Features702017-18

Jacka, F., O’Neil, A., Opie, R., Itsiopoulos, C., Cotton, S., Mohebbi, M., Castle, D., Dash, S., Mihalopoulos, C., Chatterton, M., Brazionis, L., Dean, O,. Hodge, A., & Berk, M. (2017). A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). BMC Medicine, 15(23), 1–13. https://doi.org/10.1186/s12916-017-0791-y 

Lavalleea, K.,  Zhanga, X., Michalak, J., Schneider, S., Jürgen, M. (2019). Vegetarian diet and mental health: Cross-sectional and longitudinal analyses in culturally diverse samples. Journal of Affective Disorders, 248, 147–54. https://doi.org/10.1016/j.jad.2019.01.035 

Li, X. D., Cao, H. J., Xie, S. Y., Li, K. C., Tao, F. B., Yang, L. S., Zhang, J. Q., & Bao, Y. S. (2019). Adhering to a vegetarian diet may create a greater risk of depressive symptoms in the elderly male Chinese population. Journal of affective disorders, 243, 182–187. https://doi.org/10.1016/j.jad.2018.09.033

Lee, M. F., Eather, R., & Best, T. (2021). Plant-based dietary quality and depressive symptoms in Australian vegans and vegetarians: A cross-sectional study. BMJ Nutrition, Prevention & Health, e000332. https://doi.org/10.1136/bmjnph-2021-000332

 

The Diagnostic and Statistical Manual of Mental Disorders, version 5, DSM-5 for short, classifies autism spectrum disorder, attention-deficit/hyperactivity disorder, intellectual disabilities, specific learning disorders, communication disorders, and motor disorders as neurodevelopmental disorders, or NDDs. This cluster of disorders is associated with abnormal brain development and impairments in cognition, social-emotional functioning, and speech and language skills.

A common feature of NDDs involves changes in synaptic plasticity in the brain. Synaptic plasticity is the brain’s process of modifying synaptic transmission in response to experiences and stimuli. 

 

Lifestyle factors, such as diet, impact synaptic plasticity.

 

While the underlying molecular mechanisms associated with changes in synaptic plasticity are only partially understood, lifestyle factors, such as diet, also impact synaptic plasticity. In juvenile mice studies, a high-fat diet contributed to decreased hippocampal neurogenesis, poor memory, and impaired synaptic and cognitive function. By examining the molecular mechanisms affected by a high-fat diet, defined as a diet with a 30-50% fat content, Penna and his colleagues suspected there’s potential for understanding the molecular mechanisms associated with NDDs. 

Based on their review of study findings, Penna and his colleagues developed a diagram to illustrate potential molecular mechanisms connecting metabolic dysfunction of a high-fat diet to synaptic plasticity deficits related to NDDs.

Figure 1.

(From Penna et al., 2020)

A chronic, high-fat diet contributes to low-grade inflammation in the body. Persistent activation of the body’s inflammatory response system leads to the release of proinflammatory cytokines and other hormones into the bloodstream. This results in neuroinflammation. 

 

A decrease in Brain-Derived Neurotrophic Factor (BDNF) — a neurotrophin impacting synaptic transmission, was detected after consumption of a high-fat diet.

 

An associated dysfunction of neuroinflammation is changes in synaptic plasticity. These changes could be brought on by dysregulated local protein synthesis. In mice studies, a decrease in Brain-Derived Neurotrophic Factor (BDNF) — a neurotrophin impacting synaptic transmission, was detected after consumption of a high-fat diet (Pistell et al., 2010). The resulting hypothesis is that lowered levels of BDNF may lead to lowered protein synthesis at the synapse. This contributes to mitochondrial dysfunction, which is linked to neuroinflammation, and alterations in synaptic plasticity found in NDDs — the effects of a high-fat diet.   

 

Improving the function of mitochondria in the synapse could have potential therapeutic and/or preventive benefits for neurodevelopmental disorders.

 

Since neuroinflammation and impaired synaptic plasticity are associated with NDDs, Penna and his colleagues suggested that diet changes focused on improving the function of mitochondria in the synapse could have potential therapeutic and/or preventive benefits for neurodevelopmental disorders.

 

References 

Pistell, P. J., Morrison, C. D., Gupta, S., Knight, A. G., Keller, J. N., Ingram, D. K., & Bruce-Keller, A. J. (2010). Cognitive impairment following high fat diet consumption is associated with brain inflammation. Journal of Neuroimmunology, 219(1-2), 25–32. https://doi.org/10.1016/j.jneuroim.2009.11.010

Adolescence is a developmental period commonly associated with increasing independence. With regards to eating behavior, teens and young adults take on more responsibility for exactly when they eat, along with what types of foods they choose to consume. This age group is therefore at greater risk for developing unhealthy lifestyle habits (Quehl et al., 2017). 

 

Adolescence is a developmental period commonly associated with increasing independence.

 

One lifestyle habit that tends to develop during the adolescent years is skipping meals. Hayhoe et al. (2021) explored the relationship between dietary choices and mental well-being and discovered that secondary school-age students who skipped breakfast or lunch scored lower on well-being. Well-being scores were also lower for those who chose an energy drink over eating a more traditional breakfast. Similar findings have been reported for older adolescents (Lesani et al., 2016). More specifically, college students who ate breakfast and did not skip meals reported being happier.   

So, once teens decide to eat, WHAT they eat definitely matters. Higher fruit and vegetable intake has been repeatedly linked to better mental health and well-being (Glabska et al., 2020; Guzek et al., 2020; Hayhoe et al.). Self-reported creativity, curiosity, and “eudaemonic” well-being (whether people feel engaged and experience life as meaningful and purposeful) are also greater with higher fruit and vegetable consumption (Conner et al., 2015). 

 

Higher fruit and vegetable intake has been linked to better mental health and mental well-being.

 

You may have heard of the Mediterranean diet — it has garnered much attention for its potential mental health benefits. It includes fish, fruits, vegetables, whole grains, legumes/nuts, and monounsaturated fats from olive oil. This diet prioritizes whole foods over highly processed convenience foods. Adherence to a Mediterranean diet among adolescents has been associated with higher levels of subjective happiness, mental well-being, and positive emotional states (Esteban-Gonzalo et al., 2019; Ferrer-Cascales et al., 2019; Lopez-Olivares et al., 2020). Unfortunately, teens more commonly adopt Westernized diets. These consist of high-inflammatory foods, such as refined starches, sugar, saturated fats, and trans-fats that are nutritionally deficient. Think of processed meats, chips, sugary desserts, and other “junk” foods. 

Increased symptoms of depression have been associated with diets poorer in nutritional quality among female college students (Quehl et al.). McMartin et al. (2013) noted similar findings in preadolescents; diet quality was inversely associated with feelings of worry, sadness, or unhappiness. In other words, as diet quality dropped, these negative feelings grew. Also worth noting is that inflammatory dietary components can lead to a higher risk of being in the worst mental well-being category on outcome measures of psychosocial health, quality of life, and life satisfaction in this preadolescent age group (Lycett et al., 2021). Observing the diet trends in this slightly younger age group can help us predict what food choices they will make in adolescence.  

 

Westernized diets more commonly adopted by teens consist of high-inflammatory foods.

 

On a positive note, it doesn’t take long to notice the mental health benefits of a nutrient-rich diet. According to White et al. (2013), eating fruits and vegetables predicted improvements in positive affect the following day for young adults. These meaningful changes in positive affect were noted with 7-8 servings of fruits and vegetables per day. Smith and Rogers (2014) reported that eating fruit as a mid-afternoon snack for just 10 consecutive days (versus a chocolate/crisp) was associated with lower anxiety, depression, and emotional distress.  

Researchers are just beginning to investigate dietary change as an intervention for the treatment of mental health problems. To date, Francis et al.’s 2019 study represents the only randomized controlled trial demonstrating how a brief, three-week diet intervention in young adults decreases symptoms of depression. By increasing their intake of vegetables, fruits, whole-grain cereals, protein, unsweetened dairy, fish, nuts and seeds, olive oil, and spices, and decreasing refined carbohydrates, sugar, fatty or processed meats, and soft drinks, participants saw a significant reduction in depressive symptoms. Intervention effects were even maintained at a three-month follow-up.

 

Researchers are just beginning to investigate dietary change as an intervention for the treatment of mental health problems.

 

The teen years are often characterized by greater freedom, increased opportunity, and new challenges. What adolescents eat and when they eat can impact their outlook on these experiences and affect their overall well-being. So, when addressing the question, “Is diet affecting our children’s mood, happiness, and well-being?” the answer is proving to be “Yes.” To find out more about the child diet-mental health relationship, view CNP’s Parent Research Libraries.

 

References

Conner, T. S., Brookie, K. L., Richardson, A. C., & Polak, M. A. (2015). On carrots and curiosity: Eating fruit and vegetables is associated with greater flourishing in daily life. British Journal of Health Psychology, 20(2), 413-427. https://doi.org/10.1111/bjhp.12113

Esteban-Gonzalo, L., Turner, A. I., Torres, S. J., Esteban-Cornejo, I., Castro-Piñero, J., Delgado-Alfonso, Á., Marcos, A., Gómez-Martínez, S., & Veiga, Ó. L. (2019). Diet quality and well-being in children and adolescents: The UP&DOWN longitudinal study. The British Journal of Nutrition, 121(2), 221–231.  https://doi.org/10.1017/S0007114518003070

Ferrer-Cascales, R., Albaladejo-Blazquez, N., Ruiz-Robledillo, N., Clement-Carbonell, V., Sánchez-SanSegundo, M., & Zaragoza-Marti, A. (2019). Higher adherence to the Mediterranean diet is related to more subjective happiness in adolescents: The role of health-related quality of life. Nutrients, 11(3), 698. https://doi.org/10.3390/nu11030698

Francis, H. M., Stevenson, R. J., Chambers, J. R., Gupta, D., Newey, B., & Lim, C. K. (2019). A brief diet intervention can reduce symptoms of depression in young adults – A randomised controlled trial. PLoS ONE, 14(10), e0222768. https://doi.org/10.1371/journal.pone.0222768

Glabska, D., Guzek, D., Groele, B., & Gutkowska, K. (2020). Fruit and vegetables intake in adolescents and mental health: A systematic review. Roczniki Państwowego Zakładu Higieny, 71(1), 15-25. https://doi.org/10.32394/rpzh.2019.0097

Guzek, D., Głąbska, D., Groele, B., & Gutkowska, K. (2020). Role of fruit and vegetables for the mental health of children: A systematic review. National Institute of Hygiene, 71(1), 5–13. https://doi.org/10.32394/rpzh.2019.0096

Hayhoe, R., Rechel, B., Clark, A. B., Gummerson, C., Smith, S. J. L., & Welch A. A. (2021). Cross-sectional associations of schoolchildren’s fruit and vegetable consumption, and meal choices, with their mental well-being: A cross-sectional study. BMJ Nutrition, Prevention & Health 2021; 0. http://dx.doi.org/10.1136/bmjnph-2020-000205

Lesani, A., Mohammadpoorasl, A., Javadi, M., Esfeh, J. M., & Fakhari, A. (2016). Eating breakfast, fruit and vegetable intake and their relation with happiness in college students. Eating and weight disorders: EWD, 21(4), 645–651. https://doi.org/10.1007/s40519-016-0261-0

López-Olivares, M., Mohatar-Barba, M., Fernández-Gómez, E., & Enrique-Mirón, C. (2020). Mediterranean diet and the emotional well-being of students of the campus of Melilla (University of Granada). Nutrients, 12(6), 1826. https://doi.org/10.3390/nu12061826

Lycett, K. M., Wijayawickrama, D. J., Liu, M., Grobler, A., Burgner, D. P., Baur, L. A., Liu, R., Lange, K., Wake, M, & Kerr, J. A. (2021). Does an inflammatory diet affect mental well-being in late childhood and mid-life? A cross-sectional study. British Journal of Nutrition, 17, 1-9. https://doi.org/10.1017/S0007114521001616

McMartin, S. E., Willows, N. D., Colman, I., Ohinmaa, A., Storey, K., & Veugelers, P. J. (2013). Diet quality and feelings of worry, sadness or unhappiness in Canadian children. Canadian Journal of Public Health, 104(4), e322-326. https://doi.org/10.17269/cjph.104.3845

Quehl, R., Haines, J., Lewis, S. P., & Buchholz, A. C. (2017). Food and mood: Diet quality is inversely associated with depressive symptoms in female university students. Canadian Journal of Dietetic Practice and Research : A Publication of Dietitians of Canada = Revue canadienne de la pratique et de la recherche en diététique : une publication des Diététistes du Canada, 78(3), 124–128. https://doi.org/10.3148/cjdpr-2017-007

Smith, A. P., & Rogers, R. (2014). Positive effects of a healthy snack (fruit) versus an unhealthy snack (chocolate/crisps) on subjective reports of mental and physical health: a preliminary intervention study. Frontiers in Nutrition, 1, 10. https://doi.org/10.3389/fnut.2014.00010

White, B. A., Horwath, C. C., & Conner, T. S. (2013). Many apples a day keep the blues away–daily experiences of negative and positive affect and food consumption in young adults. British Journal of Health Psychology, 18(4), 782-798. https://doi.org/10.1111/bjhp.12021

 

Elite athletes are under immense pressure to perform well. In many instances, their very livelihoods rely on them winning or performing optimally in competition. This pressure often results in an athlete feeling stressed and anxious before and during competition, something that sport psychologists refer to as pre-competitive anxiety. The majority of athletes consider anxiety to be debilitating to performance, and over 50% of sport psychology consultants working with Olympic athletes reported using techniques that help athletes to manage this anxiety during competition (Parnabas et al., 2014).

 

Pre-competitive anxiety that athletes experience, if left unmanaged, can have severe negative consequences on their overall performance.

 

The pre-competitive anxiety that athletes experience, if left unmanaged, can have severe negative consequences on their overall performance. These negative consequences can include lapses in concentration, muscle tightness, and diminished perception (Parnabas et al., 2014). In some cases, it can result in a complete breakdown of skilled technical movements, often referred to as the phenomenon of “choking” (Dong et al., 2020). 

Big sports fans (and athletes, themselves), know all too well what “choking” looks like in sport. An infamous example of this phenomenon is from Super Bowl LI, when the Atlanta Falcons were winning 28-3 in the third quarter only to end up losing by 6 points in overtime, after letting Tom Brady and the New England Patriots score 31 unanswered points for the win. Still a touchy subject for many Falcon fans out there!

Sport psychologists have been studying the phenomenon of “choking” for decades, and working with athletes to utilize techniques that lessen the impact that their anxiety has on their ability to perform. There have been several theories developed suggesting why this phenomenon occurs, many of which offer insight into how sport psychologists can work with athletes to improve their anxiety symptoms and lessen the instances of “choking” under pressure (Martens, 1990; Woodman et al., 2003; Yerkes & Dodson, 1908). Most of the skills that sport psychologists use to help their athletes manage their anxiety are relaxation techniques including deep breathing, meditation, imagery, and progressive muscle relaxation (Parnabas et al., 2014). However, even more recently researchers are beginning to investigate the impact that an athlete’s diet may have on the instances of “choking” in sport. 

 

Researchers are beginning to investigate the impact that an athlete’s diet may have on the instances of “choking” in sport.

 

Researchers in China sought to find out diet’s relationship to “choking” by studying elite divers’ performance under pressure. Dong et al. (2020), examined whether the consumption of a cultured probiotic yogurt containing live strains of beneficial bacteria could influence both the contents of an athlete’s gut microbiome and the instances of them choking under pressure in a simulated competition situation. 

Why yogurt? To understand why the researchers chose this food source, it’s important to have some background knowledge on the gut microbiome. According to the World Health Organization, probiotics are “live microorganisms which when administered in adequate amounts confer health benefits to the host” (Reid et al., 2019). When looking at several fermented foods, they found yogurt to be one of the best sources of probiotics. 

The human intestines are home to trillions of bacteria, together called the gut-microbiome. These bacteria have an impact on human physical health, and are more recently being implicated in mental health and performance (Liang et al., 2018). How does something so far away from the brain have any control over our mental processes? Well, gut bacteria produce substances such as neurotransmitters and hormones that make their way up to the brain and play a role in an individual’s response to stress, anxiety, and depression (Dong et al., 2020), something that athletes who are under pressure to perform optimally know well! Probiotics have been shown to ameliorate depression and anxiety scores in several studies because of their impact on the gut microbiome (Mohajeri et al., 2021). 

Dong et. al (2020), hypothesized that the “choking” phenomena in sport may be related to the composition of an athlete’s gut microbiome, and that supplementing an athlete’s diet with probiotics found in yogurt could both alter the composition of the gut microbiome, and lessen the instances of “choking” under pressure.

 

The “choking” phenomena in sport may be related to the composition of an athlete’s gut microbiome.

 

Because of the technical nature of their sport, elite divers are at high risk for experiencing “choking.” The researchers in this study wanted to find out if supplementing these diver’s diets with probiotics found in yogurt would help to regulate the athletes’ gut microbiome, and whether this would impact the likelihood of them “choking” under the pressure in a stimulated competition situation. This study explored two different experiments: the first being the correlation between the gut microbiome and the instances of “choking” in the athletes, and the second being the potential cause-effect relationship between supplementing the athletes’ diet with yogurt containing probiotics, and subsequent changes in the gut microbiome and the “choking” phenomena. 

To determine the correlation between the gut microbiome and instances of “choking,” researchers collected fecal matter samples to determine the microbiome contents of athletes at baseline, and then tested their performance in both high and low pressure competition-like situations. They found that there was a significant negative correlation between higher levels of the bacteria strains Bifidobacteriaceae and Lactobacillaceae, commonly thought of as beneficial bacteria strains in the gut, and the lowered instances of “choking.” They also found a significant positive correlation between the instances of bacteria Prevotellaceae in the gut, which is commonly referred to as a pathogenic bacteria strain, and “choking” (Dong et al., 2020). 

After this initial measurement, the researchers then divided the group between a high yogurt consumption group that received a higher intake of probiotic yogurt for 15 days, and a control group which did not receive extra yogurt supplementation. They then tested their gut microbiome content and their choking index, and found significant differences between the two groups in their gut-microbiome composition and their instances of “choking” under pressure! 

After the 15 day experiment, athletes in the high yogurt group had significantly lower amounts of Prevotellaceae bacteria, significantly higher amounts of Bifidobacteriaceae bacteria, and significantly lower instances of choking under pressure when compared to the control group. 

Studies like these illuminate that many aspects of human performance are impacted by the diet-mental health relationship, including sport. To find out how dietary intake patterns affect all aspects of human psychological, behavioral, cognitive, sensory-perceptual, interoceptive, and psychosocial well-being, visit the CNP Research Libraries.

 

References

Dong, W., Wang, Y., Liao, S., Lai, M., Peng, L., & Song, G. (2020). Reduction in the choking phenomenon in elite diving athletes through changes in gut microbiota induced by yogurt containing bifidobacterium animalis subsp. lactis BB-12: A quasi experimental study. Microorganisms, 8(4), 597. https://doi.org/10.3390/microorganisms8040597 

Liang, S., Wu, X., & Jin, F. (2018). Gut-Brain Psychology: Rethinking Psychology from the microbiota–gut–brain axis. Frontiers in Integrative Neuroscience, 12. https://doi.org/10.3389/fnint.2018.00033 

Martens, R., Burton, D., Vealey, R.S., Bump, L.A. and Smith, D.E. (1990) Development and Validation of the Competitive State Anxiety Inventory-2 (CSAI-2). In: Martens, R., Vealey, R.S. and Burton, D., Eds., Competitive Anxiety in sport, Human Kinetics, Chapaign, 117-190.

Mohajeri, M. H., La Fata, G., Steinert, R. E., & Weber, P. (2018). Relationship between the gut microbiome and brain function. Nutrition Reviews, 76(7), 481–496. https://doi.org/10.1093/nutrit/nuy009 

Parnabas, V. A., Mahamood, Y., Parnabas, J., & Abdullah, N. M. (2014). The relationship between relaxation techniques and sport performance. Universal Journal of Psychology, 2(3), 108–112. https://doi.org/10.13189/ujp.2014.020302 

Woodman, Tim & Hardy, Lew. (2003). The relative impact of cognitive anxiety and self-confidence upon sport performance: A meta-analysis. Journal of Sports Sciences, 21, 443-57. https://doi.org/10.1080/0264041031000101809  

Yerkes, R.M. and Dodson, J.D. (1908), The relation of strength of stimulus to rapidity of habit-formation. The Journal of Comparative Neurology and Psychology, 18, 459-482. https://doi.org/10.1002/cne.920180503

 

Today’s food landscape is full of sensory-perceptual cues that can drive us to consume high-calorie, energy-dense foods (Ravussin & Ryan, 2018). The abundance of these food cues is believed to be one of the main drivers of food overconsumption (Charbonnier, 2018), as is the availability of high-calorie, energy-dense foods. Exposure and availability are two concepts within nutritional psychology shown to influence our dietary intake behaviors and patterns.

Exposure to high-calorie, energy-dense food cues invoke a host of psychological, cognitive, behavioral, sensory-perceptual, and interoceptive processes that affect our response to these foods. This can be particularly true for those with obesity (Chao et al., 2020). The cognitive process associated with learning and memory involve the hippocampus — which is one of the structures in our brain found to be particularly vulnerable to the influence of high-calorie, energy-dense foods.

What does memory have to do with our response to food cues in our environment? Studies show that memories can influence our future food seeking for highly palatable and remembered food experiences. Let’s explore how these memories influence our response to food cues in our environment, particularly when related to memories of events we find stressful, or foods we remember as preferred.

 

Many situations that cause people to recall memories from their past are related to food.

 

Humans become conditioned to respond to food-related cues that are informed by past memory associations with previous food experiences. For example, an individual may start to associate stressful events with the feeling of reward experienced after eating high-calorie foods. Once this association is learned, encountering that same food stimulus can induce the same physiological and behavioral responses as previously experienced, including salivation, hunger, and ultimately repeated food intake (Chao et al. 2020).

A study by Chao et al. in 2020 examined whether briefly exposing individuals to their personal favorite foods or to an event they personally find stressful, would impact their hunger, anxiety, and food intake, compared with exposing them to cues that are considered ‘neutral’ to them.

Since it was hypothesized that the obese participants would have greater responses to cues than ‘normal weight’ participants, the researchers also investigated whether cue responses of hunger and food intake differed by weight status. Participants recruited were 18 to 45 years old and scored less than 40 on the BMI scale (30 and above is classified as obese).

 

It was hypothesized that the obese participants would have greater responses to cues than ‘normal weight’ participants.

 

‘Scene imagination’ questionnaires were used to find out more about the participants’ recent life events, helping to create personalized imagery scripts indicating participant’s personal stressors, favorite foods, and the cues they deemed neutral. Audiotapes were recorded using these structured and personalized scripts, and were played during the 3-day laboratory experiments to reproduce the same stressful, food, or neutral situation. In these sessions, participants were given headphones to listen to different audio recordings of these cues each day.

After each scene imagination session, each person was given free access to a buffet consisting of high-calorie snack foods such as chips, cookies, and brownies, as well as low-calorie snack alternatives including carrots and grapes. After an hour, the snack tray was carried away and examined to measure how much the person had eaten.

The results showed that food cues induced hunger to a significantly greater extent than the neutral and stress stimuli. But the weight class of the individual did not have an impact on the level of hunger evoked by food cues. A similar number of calories were consumed across the three stimuli. However, a difference was observed in the type of snacks mostly eaten by certain individuals after listening to the food and stress cue audiotapes.

In response to the food cue, those with obesity sought 81% of their calories from high-calorie snacks, which was significantly higher than ‘normal weight’ participants (63.5%). The obese subjects also recorded a significantly higher percentage intake of calories from calorie-rich snacks than their ‘normal weight’ counterparts following exposure to stress cues. Weight status, however, did not predict how much calorie-rich food a person ate following the neutral cue condition.

 

Interventions that decrease cue reactivity to food and stress may help obese individuals to cut down on calorie-rich foods.

 

This study found that obese adults obtained a greater proportion of their calories from high-calorie foods relative to ‘normal weight’ adults in response to food cues and stress, which is in accordance with previously conducted research. While these findings represent the efforts in this study only, they support the notion that people with obesity can be more vulnerable to food cues and stress, leading them to seek out more high-calorie and energy-dense foods. The study authors note that interventions that decrease cue reactivity to food and stress may help obese individuals to cut down on their intake of calorie-rich foods, and in turn, improve their diet-mental health relationship.

 

References

Chao, A. M., Fogelman, N., Hart, R., Grilo, C. M., & Sinha, R. (2020). A laboratory-based study of the priming effects of food cues and stress on hunger and food intake in individuals with obesity. Obesity (Silver Spring, Md.), 28(11), 2090–2097. https://doi.org/10.1002/oby.22952

Charbonnier, L., van Meer, F., Johnstone, A. M., Crabtree, D., Buosi, W., Manios, Y., Androutsos, O., Giannopoulou, A., Viergever, M. A., Smeets, P., & Full4Health consortium (2018). Effects of hunger state on the brain responses to food cues across the life span. NeuroImage, 171, 246–255. https://doi.org/10.1016/j.neuroimage.2018.01.012

Ravussin, E., & Ryan, D. H. (2018). Three New Perspectives on the Perfect Storm: What’s behind the obesity epidemic?. Obesity (Silver Spring, Md.), 26(1), 9–10. https://doi.org/10.1002/oby.22085

Stevenson, R., Francis, H., Attuquayefio, T., Gupta, D., Yeomans, M., Oaten, M., & Davidson, T. (2020) Hippocampal-dependent appetitive control is impaired by experimental exposure to a Western-style diet. Royal Society Open Science, 7(2).