Diet and Stress

Since it is not known whether the Mediterranean diet can reverse the increased inflammation induced by stress, this 2018 study examined the two associations - between cortisol with inflammation, and cortisol with the adolescent Mediterranean diet score (aMDS) - before testing whether aMDS associates with cortisol levels and inflammation, and whether inflammation can be reduced by aMDS. The aMDS of the 242 adolescent participants (12.5-17.5 years old) was derived from their salivary cortisol levels, blood results and 2-day 24-h dietary recall. Several relationships involving cortisol were determined, including its inverse correlation with adherence to the Mediterranean Diet (B = -1.023, p = 0.002), and association with elevated tumor necrosis factor (TNF-α B = 11.887, p = 0.001) when adjusted for age, gender, parental education and body mass index (although this became insignificant when aMDS was included in the model). Moreover, when comparing lower and higher aMDS groups, the cortisol-TNF-α interaction was only seen in the lower aMDS group. The concentrations of TNF-α and interleukins (IL) IL-1, IL-2, IL-6 were also found to be lower in individuals highly adherent to the aMDS, compared with those who did not adhere to the diet score. These findings suggest that adherence to the Mediterranean diet may counteract the stress-induced alterations in inflammatory markers, which could ultimately lower prevalence rates of mental disorders. [NPID: stress, Med diet, Mediterranean diet, inflammation, cortisol, tumor, tumor necrosis]

Since the dramatically increasing perceived loneliness among adolescents are linked with high stress levels and dysfunctional lifestyles, which are strongly influenced by eating habits, Ferrer-Cascales et al. (2018) analyzed the relationship between perceived loneliness, stress, dietary habits and adherence to the Mediterranean diet (MD) among 527 Spanish adolescents. Greater perceived loneliness and stress levels were significantly associated with lower MD adherence. It was also highlighted that dietary patterns were poorer among those adolescents with greater perceived loneliness, compared with those with low levels of perceived loneliness. Moreover, mediation analyses revealed an indirect effect of the loneliness on adherence to the MD through the mediation effect of stress. This study suggests poorer adherence to a healthy dietary pattern such as MD may play an influential role in the association between loneliness and health deterioration. [NPID: stress, loneliness, adolescents, dysfunctional lifestyles, Mediterranean diet, MD, Med diet, health deterioration]

This 2019 study aimed to identify the relationship between physical activity (determined by PAQ-A), adherence to the Mediterranean diet (MD; assessed using KIDMED), and academic stress (measured using the Scale of Academic Stress) among a sample of 515 university students. Chacón-Cuberos et al. (2019) discovered that women experienced greater levels of academic stress, especially with respect to communicating their own ideas and their academic obligations. Students in the overweight or underweight class also suffered from high levels of stress, while those less adherent to the MD scored higher for stress associated with conveying their own ideas. Physical activity could not be linked with academic stress, and nor could diet quality after controlling for sex and BMI in the regression model. Although a connection between diet quality and stress cannot be claimed, stress was associated with gender and poorer health - considering the link with being overweight. [NPID: stress, Mediterranean diet, MD, Med diet, academic stress, diet quality, gender]

In this 2016 study, adolescent Lewis rats (28 days postnatal) were given unrestricted access to either a Western-like Diet (41.4% kcal from fat) or the control diet (16.5% kcal from fat) for 8 weeks, before being exposed to a cat odor threat (to induce psychological trauma), in order to test if an obesogenic Western-like high-fat diet (WD) pre-disposes rats to post-traumatic stress responsivity. One week into encountering stress, increased anxiety-like behavior was evident in the rats fed on the WD, compared with those on the control diet (indicated by the elevated plus maze and the open field test). The high-fat diet was also associated with significant hippocampal atrophy (20% reduction) and lateral ventricular enlargement (50% increase), observed in the magnetic resonance imaging results. As well as these volumetric disturbances, leptin and FK506-binding protein 51 (FKBP51) levels were elevated, while hippocampal blood vessel density was reduced. Asymmetric structural vulnerabilities to the WD were discovered, particularly in the ventral and left hippocampus and lateral ventricle. This study demonstrates that WD consumption during adolescence influences key substrates implicated in post-traumatic stress disorder. It is important to develop our knowledge on WD’s impact on a person’s course of development since susceptibility to stress translates to greater vulnerability to neuropsychiatric disorders. [NPID: stress, animal, Western-style diet, WS diet, psychological trauma, responsivity, anxiety, hippocampus, hippocampal atrophy, PTSD, neuropsychiatric disorders]

The objective of this 2020 study was to explore the interaction between the perceived stress levels of Korean college students with their level of physical activity and dietary behaviors. Questionnaires were distributed to students on campus, while the 10-item Perceived Stress Scale (PSS-10) was employed to assess the degree of stress perceived. Demographic characteristics were also utilized to determine its influence on the students’ dietary behaviors. Regarding demographics, the eating behaviors and physical activities of the subjects were found to vary by sex, academic year, and residence type. But there were significant differences in dietary behaviors between participants with low and high levels of perceived stress. For example, those with high perceived stress ate more ready-prepared meals (p<0.001). Choi (2020) has conducted a study that has demonstrated the need for stress management in college, and that supports the provision of programs capable of fostering healthy dietary behaviors in students, especially in first year. [NPID: stress, perceived stress, Korea, college, students, stress management]

Begdache et al. (2019) states that diet may impact mental health in different ways in young adults and mature adults since full maturation of the brain is thought to be achieved at the age of 30. This study investigated the relationship between mental distress with exercise and dietary consumption and practices, and compared the differences between young adults (YA) aged 18-29 and matured adults (MA) aged 30 years and above. Additionally the researchers aimed to find out whether mental health supports exercising and healthy eating and practices. The data was collected by distributing an anonymous online survey on social media platforms. The mood of young adults appeared to depend on foods that increases availability of neurotransmitter precursors and concentrations in the brain such as frequent meat consumption and exercise, while matured adults’ mood were greatly influenced by foods such as fruits that provide antioxidants and by abstaining from foods that inappropriately activates the sympathetic nervous system (e.g. coffee, high glycemic index, and skipping breakfast). These findings may indicate that diets require adjustments as people’s brains start to mature and undergo age-related morphological and functional alterations. [NPID: stress, adults, brain maturation, mental stress, meat, exercise, fruits, antioxidants, breakfast, high glycemic, coffee, nervous system]

This 2021 study explored the prevalence rates of insomnia among adolescents and of psychological distress among young adults. The objective was to find out whether these figures show correlations with low levels of physical activity, high intake of sugar-sweetened beverages, or low consumption of whole grain bread. Data was retrieved from Trøndelag Health Study (HUNT) in Norway, which included participants in the Young-HUNT3 study (when aged 13-19) as well as those in the HUNT4 study 11 years later (at 23-31 years old). The sample consisted of 2,230 participants (1,287 females and 943 males). The adolescents self-reported their physical activity levels and their dietary intake. Those who did less physical activity were more likely to experience psychological distress at early adulthood. Psychological distress was also associated with higher sugar-sweetened beverage intake, lower ingestion of whole grain bread, and insomnia in adolescence. Moreover, unhealthy lifestyle behaviors seen during adolescence increased the risk of psychological distress in young adulthood by 3.18-6.01 percentage points. To summarize these results, several lifestyle features of adolescents showed correlations with psychological distress in young adulthood, including low levels of physical activity, drinking sugar-sweetened beverages regularly, low ingestion of whole grain bread, and insomnia.[NPID: insomnia, physical activity, exercise, whole grain, sugary drinks, psychological distress, Norway, diet, dietary habits, unhealthy diet]