Diet, Mood & Well-Being
The CNP Diet, Mood & Well-being Research Category consolidates research exploring the interconnected relationship between dietary intake and how we feel and experience mood, including creativity, happiness, well-being, etc. To view each original study on the open internet, click “Original.” To view the CNP-written abstract summary, click “CNP Summary.” While only some CNP-written abstract summaries are available below for free, all abstract summaries are available to CNP members through the CNP Library Membership.
FEATURED CNP RESEARCH SUMMARY
This 2018 study evaluates whether psychological well-being predisposes older adults to eat more fruits and vegetables. The 6,565 participants of the English Longitudinal Study of Ageing were examined over a seven-year span to determine their psychological functioning. Boehm (2018) focused on 17 items from the Control, Autonomy, Satisfaction, and Pleasure Scale (CASP-19), including pleasure, self-realization, and autonomy. From the initial stages, the participants with a greater sense of psychological well-being were shown to eat more fruits and vegetables. It was also shown that these individuals who started the study with a greater feeling of satisfaction would consume fruits and vegetables for longer over the 7 years (11% reduced risk of dropping below the recommended levels during follow-up).
2023
Household food insecurity and health service use for mental and substance use disorders among children and adolescents in Ontario, Canada
Although it is uncertain how food insecurity affects the utilization of mental health services, it is a critical public health issue connected to children's and adolescents' mental health. Anderson et al. (2023) looked to quantify the relationship between family food insecurity and contact with medical services for mental or drug use disorders among kids and teenagers (aged 1–17 years) who submitted a household answer to the Household Food Security Survey Module. Using health administrative data linked to five waves of the Canadian Community Health Survey enabled the identification of contacts with outpatient and acute care services for mental or drug use problems in the year prior to survey completion. After correcting for a number of confounding variables, prevalence ratios for the relationship between food insecurity in the household and the use of services supporting mental health were derived. Analysis of the results revealed that, of the 32 321 children and adolescents in the sample, 5216 (16.1%) were living in homes where there was a lack of food. 9.0% of the sample had an outpatient contact for a mental or drug use issue, and 0.6% had an acute care contact. Although substance use disorders were rare, children and adolescents in food-insecure households had a 55% higher prevalence of outpatient contacts for a mental or substance use disorder and a 74% higher prevalence of acute care contacts. The authors conclude that, compared to children and adolescents living in homes without food insecurity, individuals who are food insecure seek health services more frequently for mental or drug use issues. Focused initiatives to assist food-insecure households might boost the mental health of children and adolescents and ease pressure on the mental health system. [NPID: Food insecurity, mental health, substance abuse, children, adolescents, Canada]
CNP Research Summary can be found in the CNP Library Membership
2023
The relationship between a plant-based diet and mental health: Evidence from a cross-sectional multicentric community trial (LIPOKAP study)
Plant-based eating regimens may be neuroprotective and have positive effects on mental health. The correlation between a plant-based dietary index and indicators of mental health, however, is weakly supported by the available research. In this cross-sectional research study by Haghighatdoost et al. (2023), a sizeable multicentric adult sample (n = 2,033) was used to investigate the relationship between anxiety, depression, and plant-based dietary indices (PDI). The dietary intakes of the subjects were assessed using a validated food frequency questionnaire, developing a whole PDI, a healthy PDI (hPDI), and an unhealthy PDI (uPDI). The HADS (Hospital Anxiety and Depression Scale - validated Iranian version) was used to evaluate for anxiety and depression. After possible confounders (sex, age, energy, physical activity, marital status, and smoking) were adjusted, the authors noted that PDI and hPDI were unrelated to depression and anxiety. However, the crude model showed that the greatest uPDI use correlated with increasing the risk of anxiety by around 50% and around twice the risk of developing depression. The relationships were little altered after possible confounders were taken into account. The authors conclude that while whole plant-based and healthy plant-based diets were not linked to anxiety and depression, bad plant-based diets were linked to a greater risk of these conditions. [NPID: Depression, anxiety, plant based diet, vegetarian, vegan, adults, nutrition]
2023
Dietary Approaches to Stop Hypertension (DASH) diet and mental well-being: A systematic review
One of the most often recommended diets for preventing and managing hypertension is the Dietary Approaches to Stop Hypertension (DASH) diet. However, a thorough understanding of how the DASH diet affects mental health and well-being is still lacking. To close this gap, the current study by Tan, Wang & Tomiyama (2023) thoroughly investigated the most recent research on the relationship between the DASH diet and mental health. To find qualifying papers (up to May 2021), the Web of Science, PsycINFO, and PubMed databases were thoroughly searched to include English-language interventional and observational studies that drew conclusions regarding mental health. Using the NIH quality evaluation method, two writers independently evaluated the examined papers' quality and gathered qualitative information. The senior author decided on conflicts. The final review comprised 16 trials with 48824 individuals: Six randomized controlled trials and ten observational studies. The studies' methodological quality was generally of medium strength. There were contradictory findings on psychological tests, but overall, analysis of the results revealed that the DASH diet was linked to better mental health outcomes. A negative correlation between following the DASH diet and depressive symptoms/depression was found in five observational studies. According to four randomized controlled trials, the DASH diet has been shown to improve mental health, including quality of life and emotional symptoms. Thus, the authors conclude that the DASH diet may benefit mental health. However, the findings varied between published studies, which may be related to variations in the methodologies used to evaluate the DASH diet's effects on mental health outcomes. The authors recommend that future research focus on well-powered randomized controlled trials with mental health as the main goal. [NPID: DASH diet, dietary index, epidemiology, mental health, psychological well being, systematic review]
CNP Research Summary can be found in the CNP Library Membership
2021
Understanding the interactions of happiness, self-rated health, mental feelings, habit of eating healthy and sport/activities: A path model for Abu Dhabi
In this study by Badri et al. (2021), the authors used data from a Quality of Life survey conducted in the city of Abu Dhabi (September 2019 - March 2020, participants aged 15 and above, n = 72,034) to investigate the links between how we perceive health, happiness, healthy eating habits, psychological symptoms of mental health and physical activity. Analysis of participant responses to the online survey revealed three distinct mental variables as pathways to perceived happiness, namely, “having lots of energy,” “feeling calm and peaceful,” and “feeling downhearted and depressed.” Happiness also correlated positively with self-rated health, and positively related to “often doing physical activities.” On the other hand, mental variables relating to “often feeling rushed or pressed for time” are linked directly to self-rated health only. Finally, the consumption of healthy food was substantially linked to the self-perception of health and happiness domains. The authors conclude by discussing their study’s limitations, and recommendations for future research, and present these findings to improve policymakers' understanding of self-rated health and happiness to guide efficient decision-making. [NPID: Eating healthy, happiness, mental health, path analysis, physical activities, self rated health]
2021
Consumption of dietary guidelines for Americans types and amounts of vegetables increases mean subjective Happiness Scale scores: A randomized controlled trial
Dietary intake of fruits and vegetables (FV) confers several health benefits. Recent evidence from observational and intervention studies postulates that consuming FV could also enhance psychological well-being. Based on these findings, De Leon et al. (2022) conducted their randomized controlled trial to examine the impact of FV consumption according to the 2010-2015 Dietary Guidelines for Americans (DGA) on mean Subjective Happiness Scale (SHS) scores in a population of 75 individuals (age 18-65 years old, Body Mass Index ≥ 25, low dietary vegetable intake). The study included an eight-week feeding phase, where study participants were divided into two groups, and those in the intervention group received a supply of vegetables compliant with DGA recommendations. At the end of week 8, SHS scores were evaluated. Analysis of the results revealed a substantial increase in SHS scores in individuals who received vegetables, while the control group did not show any changes in SHS scores compared to their baseline. Thus, the authors conclude that enhancing dietary vegetable intake to comply with DGA recommendations leads to a substantial increase in SHS scores, highlighting the benefit of DGA vegetable intake recommendations in enhancing psychological well-being. [NPID: Dietary Guidelines for Americans, fruits and vegetables, happiness, psychological well-being, vegetable consumption]
CNP Research Summary can be found in the CNP Library Membership
2021
A differential threshold of breakfast, caffeine and food groups may be impacting mental well-being in young adults: The mediation effect of exercise
Young adults (YA) are increasingly vulnerable to mental stressors. Research has shown that physical exercise and diet modulate mental health, however, the understanding of the underlying mechanisms remains insufficient. Although YA are physically active, their dietary intake is poor in quality. In this study by Begdache et al. (2021), the authors investigated the links between diet, exercise, and mental health in a population of YA (n = 1804, 644 males, 18 - 29 years of age) through the use of a Food-Mood questionnaire. Results were incorporated in casual loop diagrams (CLD) that accounted for participant gender, demonstrated that a certain threshold of dietary quality and physical exercise is required to achieve optimum mental well-being, and highlighted a necessity for adjusting exercise, and dietary quality to enhance mental well-being in YA. Finally, the authors comment that their findings demonstrate how physical exercise may enhance the impact of diet on improving mental health and ameliorating negative mental stressors. [NPID: Young adults, mental health, diet, exercise, mental stressors]
2022
Frequency of fruit consumption and savoury snacking predict psychological health; selective mediation via cognitive failures
Despite increasing evidence pointing to the relationship between diet and psychological well-being, the evidence examining how foods rich in nutrients (like fruits and vegetables) and foods deficient in nutrients (like sweet and savory energy-dense snacks) affect psychological well-being remains insufficient. In the same vein, the mechanisms modulating the links between psychological health and dietary intake are not well understood. This spurred Tuck and colleagues (2022) to conduct their cross-sectional study on understanding the links between psychological health and dietary intake through examining cognition in a population of 428 adults (age = 39.7 ± 13.0, 53% female), where study participants completed several validated questionnaires that evaluated their psychological health and dietary habits. Analysis of the results demonstrated a reduction in depressive symptoms and improved psychological well-being in participants who ate fruits regularly, while the regular intake of savory snacks was associated with higher levels of anxiety, depressive symptoms, stress, cognitive failures, and negative psychological well-being. The authors highlight how their results showcase the impact of individual food items on psychological health, and the mechanisms behind these relationships. Furthermore, the authors comment on the necessity of conducting additional studies to further understand the existing cause-and-effect relationships and to explore the possibility of using dietary interventions to modulate psychological health, whether directly or indirectly. [NPID: Fruits, vegetables, snacking, cognition, psychological health, mental health, well-being]
CNP Research Summary can be found in the CNP Library Membership
2022
Hangry in the field: An experience sampling study on the impact of hunger on anger, irritability, and affect
Insufficient research has been conducted to explore the links between hunger and negative emotions and affect, a condition known in layman’s terms as being “hangry.” In this study by Swami et al. (2022), the authors investigated the relationship between daily experiences of hunger and negative emotions through experience sampling in a population of 64 participants over the course of 3 weeks. The participants reported feelings of hunger, anger, irritability, pleasure, and arousal, five times a day for a total of 9,142 responses. Analysis revealed a significant relationship between higher levels of self-reported hunger and pronounced feelings of anger and irritability, in addition to declining pleasure. These relationships remained consistent as participant variables like sex, age, body mass index, dietary behaviours, and trait anger were accounted for. No significant relationships with feelings of arousal were observed. In conclusion, the authors comment that the extent of hunger one may experience is directly related to negative emotions, which provides evidence to justify feeling “hangry.” [NPID: Emotions, eating habits, hunger, aggression]
2021
The evaluation of dark chocolate-elicited emotions and their relation with physico chemical attributes of chocolate
The aim of this 2021 study was to assess the emotions induced by eating dark chocolates of different origins including Venezuela, Peru, and Ghana. Another objective was to determine the association among overall acceptability of the chocolates, emotions induced, and the different chocolate attributes such as quantity of fatty acids and volatile compounds. The FaceReader 8 software was used to measure chocolate-elicited emotions, characterizing the participants’ facial expressions as either happy, neutral, sad, angry, surprised, scared, disgusted, contempt, valence, or arousal. The intensity of the “happy” emotion was the highest in the subjects out of every measured emotion. In many cases, the dark chocolates had a significant influence on the emotions induced, while the origin of the chocolates had a considerable effect on the levels of many volatile compounds, and on the contents of several main fatty acids. There were notable correlations between chocolate-triggered emotions, and separate fatty acids and volatile compounds. Overall, the origin of dark chocolate appeared to have a marked impact on emotions and physicochemical attributes of chocolates. Moreover, separate fatty acids and volatile compounds can be used as quality indicators since they have been linked with overall acceptability of the chocolates and with elicited emotions. [NPID: mood, chocolates, dark chocolate, fatty acids, diet, emotions, happy, happiness, aromatic]
CNP Research Summary can be found in the CNP Library Membership
2018
An electronic ecological momentary assessment study to examine the consumption of high-fat/high-sugar foods, fruits/vegetables, and affective states among women
Here, Liao et al. (2018) examines the interaction between high-fat, high-sugar (HFHS) foods, and fruit and vegetable (FV) consumption with affective states (the underlying experience of feeling, emotion or mood) among women. The 202 female participants’ levels of HFHS foods and fruit and vegetable intake in the previous 2 hours was reported as well as their current affective states across 1 week. It was later revealed that fruit and vegetable consumption over the previous 2 hours positively correlated with the feeling of happiness. Conversely, higher average sadness was observed among individuals who either ate more HFHS foods or less fruits and vegetables than others in the study. The overweight/obese women who ate high-fat and high-sugar foods more frequently also experienced greater stress on average when compared to the normal-weight ladies. Thus, this relationship between HFHS food consumption and stress may be stronger in overweight and obese females than normal weight women. [NPID: mood, high-fat high-sugar foods, HFHS, fruit, vegetables, affect, obesity]
2017
Dietary patterns and mental health after myocardial infarction
In this 2017 study, Rius-Ottenheim et al. examined the relationship between dietary patterns and mental health among elderly patients (age range 60-80 years) who have previously suffered a myocardial infarction. The data from the Alpha Omega cohort (2171 participants) was used, including information on depressive symptoms, dispositional optimism, and diet. The average age of the subjects was 72.2 years old and 79.5% were men. One of the diet scores (the Dutch Healthy Nutrient and Food Score) was associated with fewer depressive symptoms and increased dispositional optimism, while the other diet score (the Dutch Undesirable Nutrient and Food Score) was not linked with any of these mental health measures. The most notable interactions were between the consumption of vegetables, fruits, whole grains, fish, and low fat-dairy with lower prevalence of depressive symptoms and higher optimism. A healthy dietary pattern appears to be related to lower risk of depression and a more optimistic personality, although the direction of causality of this association needs to be clarified. It is possible that the more optimistic individuals make healthier food choices. [NPID: mood, happiness, well-being, depression, optimism]
CNP Research Summary can be found in the CNP Library Membership
2020
Food and mood: How do diet and nutrition affect mental wellbeing?
In this study, Firth et al. (2020) sought to understand the dynamic between diet and mental health, in particular which specific foods and dietary patterns are related to mental health conditions. The most common of these mental health conditions are depression and anxiety, which affect a vast percentage of people both in their functioning and health. New approaches are needed to better manage clinically diagnosed and subclinical depression and anxiety. Diet-related studies over the last few years have linked specific dietary patterns such as Mediterranean or healthy, and the high consumption of fruits, vegetables, nuts, and legumes, and moderate intake poultry, eggs, and dairy products, with reducing risk of developing depression. But there are other factors to consider when analyzing diet’s relationship with mental health, such as barriers to maintaining a favourable diet (finances, side effects of medications, and other environmental factors). Humans can also make different food choices based on their temporary psychological state — eating “comfort foods” at periods of low mood, for example. This review discusses this important but complex, multidirectional relationship between diet and mental health. [NPID: mood, happiness, well-being, depression, anxiety, mediterranean diet, comfort food]
2012
Mild dehydration affects mood in healthy young women
Armstrong et al. (2012) identified the lack of data on what impact mild dehydration has on cognitive function, and investigated mild dehydration among 25 female participants (age 23.0 ± 0.6 y), achieved by intermittent moderate exercise without hyperthermia, and analyzed its influence on the women’s cognitive function. Three 8-hour placebo-controlled experiments were set up for the women, involving a different hydration state each day: dehydration through exercising without diuretic (DN); exercise-induced dehydration as well as 40mg of the diuretic, furosemide (DD); and euhydration (EU). Cognitive ability, symptoms of dehydration and mood were all monitored during each experiment, 3 times at rest and during each of 3 exercise sessions. The DN and DD trials, when pooled together, achieved a 1.36 ± 0.16% loss of body mass. When the various pooled readings were compared with the EU group, the adverse effects of dehydration were evident both at rest and during exercise when looking at vigor-activity, fatigue-inertia, and total mood disturbance scores of the Profile of Mood States, as well as for task difficulty, concentration, and headache (as assessed by questionnaire). However, cognitive performance was unaffected, and the serum osmolarity, which is an indicator of hydration level, was actually higher in the coupled DD-DN trials, compared with the EU group. To conclude, inducing 1.36% dehydration in females lowered their concentration levels and mood, and increased headaches and perception of task difficulty. Now warranted are studies investigating optimal hydration during and after moderate exercise. [NPID: mood, happiness, well-being, dehydration, cognition, task difficulty, concentration, headaches, exercise]
CNP Research Summary can be found in the CNP Library Membership
2020
Fruit and vegetable intake and mental health in adults: A systematic review
This 2020 systematic review was conducted to evaluate the relationship between fruit and vegetable intake and mental health in adults, using peer-reviewed observational studies found on either PubMed or Web of Science databases. Further searches were performed manually through inspection of references from the included studies, which increased the number of included studies for the narrative synthesis of findings to 61. The majority of studies were centered around depression and depressive symptoms, although a range of characteristics were assessed overall, from quality of life to attempted suicide. Głąbska et al. (2020) highlight a particular set of findings that indicate greater overall consumption of vegetables and fruits, as well as some subgroups (berries, citrus, and green leafy vegetables) may increase optimism and self-efficacy, while reducing psychological distress, cancer fatalism, ambiguity, and contributing to the prevention of depressive symptoms. It was difficult to compare the findings of all the studies given the variations in methodologies and samples used, which was a limitation, but the review as a whole concluded that fruits and vegetables, processed and natural, as well as their specific subgroups, may elicit positive effects on mental health. The authors advised to consume at least 5 selections of fruit and vegetables daily to improve mental health. [NPID: mood, happiness, well-being, fruit, vegetables, depression, suicide, optimism, self-efficacy, psychological distress, cancer]
2019
The association between diet and mood: A systematic review of current literature
This 2019 systematic review searched 6 databases (PubMed, Cochrane's Library, Science Direct, Scopus, Google Scholar, and ISI Web of Science) for current literature on the association between diet and mood. The Newcastle-Ottawa Scale and Jadad scale for reporting randomized clinical trials were utilized to measure the quality of the 18 studies that met the inclusion criteria and were later included in this review. The findings were not consistent across the studies, although it appears that diets such as DASH, vegetable-based diets, as well as glycemic load-based, ketogenic, and Paleo diets are perhaps the more effective mood-enhancing diets. Arab et al. (2019) concluded that more research is required to examine this relationship over a longer time period to confirm associations at this point. [NPID: mood, happiness, well-being, DASH, vegetables, keto, ketogenic diet, paleo, mood-enhancing]
CNP Research Summary can be found in the CNP Library Membership
2014
Mood, food, and obesity
This 2014 article describes the complex nature of food consumption and its link with mood and brain signalling, while also touching on the sensations of reward and gratification associated with eating certain foods — the dangerous sequence of biological events that overrides an individual's satiety and hunger signals. This constant search for dopamine, the chemical that activates reward and pleasure centers in the brain, can often lead to overeating and morbid obesity, which in addition stem from many biological factors engaging both central and peripheral systems in a bi-directional manner involving mood and emotions. Overeating and obesity can even result from the changes in food choice and consumption levels induced by altered mood and emotional eating. [NPID: mood, happiness, well-being, psychological distress, brain signaling, reward, gratification, satiety, dopamine, obesity, emotional eating]
2019
Linking what we eat to our mood: A review of diet, dietary antioxidants, and depression
This 2019 review investigated the benefits of dietary patterns and consumption of certain foods on depression. The balanced Mediterranean Diet was found to reduce risk of depressive symptoms, while the Western Diet consisting of more saturated fats and refined sugars would more likely lead to depression by disturbing gut microflora and reducing nutrient absorption. Furthermore, sugar intake in sugar-sweetened drinks was positively associated with depression, while the consumption of certain foods such as fish, fruits, and vegetables had a beneficial effect on symptoms. The use of the antioxidants green tea polyphenols or isoflavonoid have been shown to reduce signs of depression. The influences of food and nutrients are important factors to consider when clinically treating depression. [NPID: mood, happiness, well-being, psychological distress, diet, nutrition, mental health, depression, mediterranean diet, saturated fat, refined sugar, gut microbiota, microbiome, nutrient absorption, fish, fruits, vegetables, green tea, polyphenols]
CNP Research Summary can be found in the CNP Library Membership
2017
The role of diet and nutrition on mental health and wellbeing
In this 2017 editorial, the aim was to set the scale of the mental illness problem into context while presenting recent evidence linking nutrition to psychological outcomes. Owen and Corfe (2017) wrote that the intent of the 2016 Nutrition Society Winter Meeting, "Diet, nutrition and mental health and wellbeing," was to review where the evidence was strong, where the data was lacking, and to discuss findings with others in the communities working in this area of research. This meeting, as well as the present research in the field, led Owen and Corfe (2017) to theorize that even dietary-based interventions with relatively small effect sizes may significantly reduce the disease burden of mental and neurological diseases. [NPID: mood, happiness, well-being, psychological distress, diet, nutrition, mental health]
2020
Associations among diet, the gastrointestinal microbiota, and negative emotional states in adults
This study conducted a cross-sectional examination of dietary intake, subjective emotional state, and faecal microbial taxa abundances in 133 adults (ages 25-45) without physician-diagnosed mood disorders in order to explore the relationships among their diets, gastrointestinal microbiota, and mood. Habitual dietary consumption was indicated using the National Cancer Institute’s Diet History Questionnaire II, diet quality was evaluated with the 2010 Healthy Eating Index (HEI), subjective mood state was assessed using the 42-item Depression, Anxiety, and Stress Scale (DASS-42), while fecal DNA was also extracted and a region of the rRNA gene was sequenced and subsequently analysed using QIIME2. The data showed sex-dependent associations among 21 bacteria taxa and DASS-42 scores, including an inverse relationship between anxiety scale scores and Bifidobacterium in females and an inverse relationship between depression scale scores and Lactobacillus in males. Furthermore, the total fruit and dairy components of HEI were negatively associated with Depression and Stress scales, respectively. The findings of this study suggest that gastrointestinal microbes are connected to mood in adults without diagnosed mood disorders, that these relationships differ by sex, and that they are influenced by dietary fibre intake. If future gut-microbiota-brain studies were to incorporate dietary intake into their research, they may be able to confirm roles of specific microbes and dietary components in mental health symptoms. [NPID: mood, happiness, well-being, psychological distress, emotional state, microbiota, microbiome, gut health, lactobacillus, fruit, vegetables, fiber]
CNP Research Summary can be found in the CNP Library Membership
2020
Food and mood: How do diet and nutrition affect mental wellbeing?
This short 2020 article sought to analyse the complex relationship between food and mental health, answering questions on carbohydrates, dietary patterns, and bacteria in the gut, and explaining how these factors could be affecting our mood and depressive tendencies. Firth et al. (2020) state that healthy eating patterns such as the Mediterranean Diet are associated with reduced risk of depression and better mental well-being compared to “unhealthy” eating patterns, namely the Western diet. This article links certain foods and eating patterns with glycaemia (concentration of sugars in your body), immune activation and responses, and the gut microbiome to provide insight into how food and mood are closely related. In addition to physical health risks, diets with a high glycaemic index (eg. diets containing high amounts of refined carbohydrates and sugars) are found to be associated with depressive symptoms. High-calorie meals rich in saturated fat appear to stimulate immune activation and inflammation, which is the proposed mechanism by which the Western diet may have detrimental effects on the brain, including cognitive decline, hippocampal dysfunction, and damage to the blood-brain barrier. Moreover, ingestion of probiotics, which theoretically target the gut microbiome, can alter the brain’s response to a task that requires emotional attention and may reduce symptoms of depression. It is highlighted that more research into the complex pathways through which diet and nutrition can influence the brain is required, particularly interventional research investigating if, how, and when dietary interventions can be used to prevent mental illness or reduce its symptoms. [NPID: mood, happiness, well-being, psychological distress, gut microbiota, depression, mediterranean diet, glycaemia, immune system, gut microbiome, microbiome, hippocampus]
2016
Trans fatty acid intake is related to emotional affect in the Adventist Health Study-2
Trans fatty acids (primarily from margarines), polyunsaturated fatty acids (PUFAs), and their inverse associations on positive affect and positive associations with negative affect were hypothesised in this 2016 study. The participants, taken from the Adventist Health Study-2, completed a food frequency questionnaire in 2002-2006 before those identified with cardiovascular disease were excluded to create this present study's subset of 8,771. These participants completed the Positive and Negative Affect Schedule (PANAS) in 2006-7, and linear regression analysis was performed (controlling for age, gender, ethnicity, education, body mass index, exercise, sleep, sleep squared, Mediterranean diet, total energy intake, and alcohol). The hypothesis was confirmed; increased trans fatty acid intake was linked to more negative affect (p<0.001), while being inversely associated with positive affect (p<0.001). While n-3 PUFAs could not be associated with either positive nor negative affect, the inverse association between the n-6:n-3 PUFA ratio with positive effect suggests that emotional affect can be improved by not only a low trans fat diet but also by the right n-6:n-3 PUFA ratio. [NPID: mood, happiness, well-being, psychological distress, trans fatty acids, polyunsaturated fatty acids, PUFAS, cardiovascular disease, affect, trans fat]
CNP Research Summary can be found in the CNP Library Membership
2019
Mental health status and dietary intake among California adults: A population-based survey
Banta et al. (2019) used the California Health Interview Survey (representing 27.7 million adults’ answers annually) stretching from 2005-2015 to explore the relationship between mental health and dietary consumption. Kessler-6 scores allowed categorisation of the giant cohort into no/low (NLPD), moderate (MPD) and serious psychological distress (SPD). 13.2% of the population studied were found to have MPD, and 3.7% had SPD. After adjusting for a range of factors (including BMI, geography, year, gender, age, race, education, marital status and poverty), the following were significantly associated with MPD and SPD: lower consumption of fruits and vegetables, and increased intake of french fries, fast food, soda, and variance-adjusted daily teaspoons of sugar. In this study, the trends all pointed to the risk of experiencing MPD or SPD rising in individuals who consume unhealthy foods. [NPID: mood, happiness, well-being, psychological distress, fruits, vegetables]
2019
Assessing the effects of vegetable consumption on the psychological health of healthy adults: a systematic review of prospective research
This 2019 review analysed the potential association between vegetable consumption and mental health. Many studies have grouped fruits and vegetables together and examined their psychological effects but in this review, only research with data on vegetable intake alone was included. The total sample size taken from 10 different studies was 33,645. Out of all the healthy non-clinical adults, two thirds reported feeling better on the vegetable only group in relation to depressive symptoms. When the recommended amount of both fruits and vegetables were eaten, psychological well-being improved. However, its efficacy in reducing negative mental health symptoms was unclear. This begs the question of if more research work should be undertaken on vegetables alone and their potential role in the treatment of psychological disease. [NPID: mood, happiness, well-being, depression, psychological disease]
CNP Research Summary can be found in the CNP Library Membership
2018
Longitudinal associations between psychological well-being and the consumption of fruits and vegetables
This 2018 study evaluated whether psychological well-being predisposes older adults to eat more fruits and vegetables. The 6,565 participants of the English Longitudinal Study of Ageing were examined over a seven year span to determine their psychological functioning. Boehm (2018) focused on 17 items of CASP-19 including pleasure, self-realisation, and autonomy. From the initial stages, the participants with a greater sense of well-being were shown to eat more fruits and vegetables. It was also shown that these individuals who started the study with a greater feeling of satisfaction would go on to consume fruits and vegetables for longer over the 7 years (11% reduced risk of dropping below the recommended levels during follow-up). [NPID: mood, happiness, well-being, fruits, vegetables, psychological functioning, pleasure, self-realisation, autonomy]
2018
Food for mood: Relevance of nutritional omega-3 fatty acids for depression and anxiety
Since polyunsaturated fatty acids (PUFAs) are abundant in the brain and have been linked to anxiety and depression, Larrieu & Laye (2018) analysed the role of the PUFA omega-3 (ω3) series in the prevention and treatment of neuropsychiatric diseases. The review delves into the potential mechanisms of ω3 PUFAs in altering the neurobiological processes leading up to depression and anxiety. [NPID: mood, happiness, well-being, PUFA, anxiety, depression, polyunsaturated fatty acids]
CNP Research Summary can be found in the CNP Library Membership
2017
Fruit and vegetable consumption and psychological distress: Cross-sectional and longitudinal analyses based on a large Australian sample
This 2017 study examined the association between fruit and vegetable consumption and incidence of psychological distress. It examined 60,404 Australian adults aged 45 and over using the validated Kessler Psychological Distress Scale (K10) to assess psychological distress (indicated by high K10 scores >22) and a short validated questioning system to determine their fruit and vegetable (FV) intake. Participants were examined in 2006-2008 and in 2010 for a follow-up. Lower prevalence of psychological distress was associated with increased FV intake even after both minimal and full adjustments on sociodemographic and lifestyle risk factors. Many of these associations were significant in the medium-level FV consumption but not significant in the highest FV consumer group in fully adjusted models. The results of this study suggest that increasing dietary intake of fruits and vegetables in middle-aged and older adults may help reduce chances of psychological distress, although more research is encouraged to find the optimal quantity. [NPID: mood, happiness, well-being, fruit, vegetables, psychological distress]
2015
Mitigation of inflammation-induced mood dysregulation by long-chain omega-3 fatty acids
This 2015 study found positive links between the ratio of Long-Chain Omega 6 fatty acids (LCn-6) to Long-Chain Omega 3 fatty acids (LCn-3) and low eicosapentaenic acid (EPA) and/or docosahexaenoic acid (DHA) biostasis with the incidence of mood disorders, major depressive disorder, and bipolar disorder. This is explained by the implication of LCn-3, EPA, and DHA possessing anti-inflammation properties. Therefore, it is predicted that increased intake in LCn-3 could relieve mood disorder through reducing immune-inflammatory signalling. [NPID: mood, happiness, well-being, omega-6 fatty acids, omega-3 fatty acids, DHA, EPA, major depressive disorder, MDD, bipolar disorder, BD, inflammation]
CNP Research Summary can be found in the CNP Library Membership
2015
On carrots and curiosity: Eating fruit and vegetables is associated with greater flourishing in daily life.
In this 2015 study, eudaemonic well-being and behaviours were measured against fruit and vegetable (FV) consumption in young adults. The experiment involved 405 subjects writing a daily internet diary noting any intake of crisps, sweets, fruits, and vegetables. Greater average eudaemonic well-being, increase in creativity, and intensity in curiosity were seen in those young adults who ate more fruits and vegetables than those consuming less, and on days when participants ate more FV compared to the days when they didn’t eat as much FV. While this study suggests increased FV can improve eudaemonic happiness, creativity and curiosity, there was little evidence of the benefits of eating crisps and sweets. [NPID: mood, happiness, vegetables, fruit, eudaemonic well-being, creativity, curiosity]
2019
Lettuce be happy: A longitudinal UK study on the relationship between fruit and vegetable consumption and well-being.
Due to the scarcity of studies using this method, Ocean et al. (2019) decided to adopt the panel data analytical technique to investigate the relationship between increased consumption of fruits and vegetables and psychological well-being. The same individuals were questioned a total of 3 times between 2010 and 2017 as part of the UK Household Longitudinal Survey. The fixed-effects regression estimates using a reversed form of GHQ-12 demonstrated that as the number and frequency of fruit and vegetable intake increased, so did the well-being of the participant. The results suggest that the relationship is robust and the subjective aspect of the study should be negligible. After comparing age with fruit and vegetable consumption, a hump-based relationship was found. [NPID: mood, happiness, vegetables, well-being, fruit]
CNP Research Summary can be found in the CNP Library Membership
2017
Healthy food choices are happy food choices: Evidence from a real life sample using smartphone based assessments
Using smartphone-based ecological momentary assessment, this 2017 study measured immediate changes in eating happiness levels over eight days. 14 different food types were investigated in this study, including healthy options such as vegetables and high-caloric foods such as sweets. Contrary to popular belief that high-caloric foods elicit happiness and counter negative moods, there were surprisingly comparable results between sweets and healthier foods, and between dinner and snacking. Vegetables had the most profound positive impact on eating-induced satisfaction over the course of the study. [NPID: mood, happiness, vegetables, well-being]
2015
Switching to a 10-day Mediterranean-style diet improves mood and cardiovascular function in a controlled crossover study
Lee et al. (2015) explored changes in mood and cognitive and cardiovascular function in response to a 10-day Mediterranean-style dietary intervention. The foods associated with countries bordering the Mediterranean Sea include legumes, olive oil, and fish, and are linked to a reduced risk of developing depression. This crossover study randomly divided 24 women into two groups differing in diet: one was given a Mediterranean diet for 10 days and the other remained on their regular diet for the same length of time, before the diets of both groups were switched to those of the other group for another 10 days. In this study the Mediterranean diet was found to be a mood enhancer (raised contentment and alertness) and improve memory recall and cardiovascular features. These findings were not affected by the order in which diets were adopted, and shows promise for treating mood disorders long-term. [NPID: mood, cognition, mediterranean diet, depression, contentment, alertness, memory, cardiovascular function, well-being]
CNP Research Summary can be found in the CNP Library Membership
2020
KiwiC for vitality: Results of a randomized placebo-controlled trial testing the effects of Kiwifruit or vitamin C tablets on vitality in adults with low vitamin C levels
Conner et al. (2020) state that fruits and vegetables containing high concentration of vitamin C have been linked to greater feelings of vitality but rarely has it been studied in randomised controlled trials. This is why Conner and her team of researchers took 167 young adults (61.1% female, aged 18-35) with vitamin C levels of less than 40 micromoles per liter in the blood and randomly assigned them into one of three intervention conditions including, kiwifruit (given 2 SunGold™ kiwifruits to eat every day), vitamin C (250mg tablet daily), and placebo (involving taking 1 tablet daily). The trial consisted of a two-week lead-in, four-week intervention, and two-week washout, and its purpose was to measure the effect of eating the kiwifruit (a vitamin C-rich food) on the participants’ vitality and to find out whether these effects are driven by vitamin C. Questionnaires on vitality and plasma vitamin C were undertaken every 14 days while sleep quality and physical activity was also self-reported every couple of days through smartphone surveys. The trial found vitamin C levels reached saturation levels within two weeks for both the kiwifruit and vitamin C groups. The kiwifruit-consuming subjects improved in mood and well-being during the 4-week intervention period, and these effects were sustained during washout. In the vitamin C tablet group, less fatigue and enhanced well-being were observed but only in those with consistently low vitamin C levels during the lead-in. The three-day food diaries taken also uncovered a reduction in fat intake by the kiwifruit group during the intervention period. No changes in plasma vitamin C status or vitality were found in the placebo group. The effects of these interventions remained significant after adjustments for age and ethnicity were made, and were not explained by sleep quality, physical activity, BMI, or dietary patterns like fat intake. Since kiwifruit consumption correlated with increased vitality in adults with low vitamin C status, a similar but not identical impact to that of vitamin C tablets, these findings suggest that the additional properties of kiwifruit may contribute to improved vitality. [NPID: mood, fruits, vegetables, vitamin C, kiwi, vitality]
2016
Evolution of well-being and happiness after increases in consumption of fruit and vegetables
This 2016 study evaluated whether an enhanced level of psychological well-being directly correlates to the quantity of fruits and vegetables consumed. Food diaries from 2007, 2009, and 2013 were taken from 12,385 Australian adults randomly selected in the "Household, Income, and Labour Dynamics in Australia" Survey (HILDA). A greater consumption of fruit and vegetables was found to have a positive relationship with psychological health, shown by the jump in satisfaction points associated with consuming 8 added portions a day. These psychological gains were found to equal the happiness achieved by changing from being unemployed to employed. [NPID: mood, fruits, vegetables, employment, unemployment, well-being]