Foods, Nutrients and Dietary Patterns in Relation to Irrational Beliefs and Related Psychological Disorders: The ATTICA Epidemiological Study

Dietary eating patterns, dairy consumption, and anxiety: A systematic literature review

BACKGROUND

Nutrition affects both physical and mental health but evidence is mixed regarding potential associations between anxiety and diet, particularly dairy consumption. We conducted a systematic literature review (SLR) of dairy consumption and/or various dietary patterns and risk of anxiety.

METHODS

Literature searches were conducted in PubMed and Embase. All study designs except case reports, small case series, and SLRs were considered for inclusion. Reference lists of previously published SLRs were reviewed for any relevant additional studies. Studies of populations without dairy sensitivities exploring the association between dietary patterns and/or dairy consumption and anxiety published through May 2022 were identified using predefined eligibility criteria. Study quality was determined using the Academy of Nutrition and Dietetics Quality Criteria Checklist.

RESULTS

For this SLR, 132 studies were included; 80 were cross-sectional. Studies examined different dietary patterns (e.g., Mediterranean, gluten-free) and anxiety using various anxiety scales, with 19 studies specifically reporting on whole dairy consumption and anxiety. Dairy consumption was significantly associated with a lower risk of anxiety in 7 studies, while the remaining 12 studies showed no significant associations. Evidence was mixed for the association between various dietary patterns and anxiety, but more studies observed a lower risk of anxiety with greater adherence to "healthy" diets (e.g., Mediterranean, diet quality score, vegetarian/vegan) than a higher risk. Notable heterogeneity in study populations, time periods, geographical locations, dietary assessment methods, and anxiety scales was observed.

CONCLUSIONS

The results of this SLR suggest a potential link between diet including diary consumption and anxiety, but future studies, especially with longitudinal designs that measure diet and anxiety at several timepoints and comprehensively adjust for confounders, are needed to fully understand the relationship between diet and anxiety.

Comparison of maternal versus postweaning ingestion of a high fat, high sucrose diet on depression-related behavior, novelty reactivity, and corticosterone levels in young, adult rat offspring

Consumption of a Western-type diet, high in fat and sugar, by mothers as well as maternal weight gain and obesity during gestation and lactation may impact offspring risk for mood and cognitive disorders. The objective of this study was to determine if ingestion of a high fat, high sucrose (HFS) diet by rat dams during gestation and lactation or by their pups after weaning impacted these behaviors and stress responsivity in young, adult offspring. To accomplish this, dams consumed either a 45% fat/high sucrose (HFS) diet or the AIN93G control diet during gestation and lactation. At weaning, pups from dams that consumed the HFS diet were weaned to the control diet. Pups from dams assigned to the control diet were weaned to either the control or HFS diet. Pup behavioral testing began at 10 weeks of age. Pups whose dams consumed the HFS diet during gestation and lactation exhibited increased depression-related behavior and baseline serum corticosterone levels, but no difference in peak levels in response to stress. Male pups of these dams displayed increased working memory during acquisition of the holeboard task and tended to exhibit more anxiety-related behavior in the elevated O-maze test. Regardless of when consumed, the HFS diet increased novelty reactivity in the open field test. These data indicate that diet but not maternal weight gain during gestation impacts offspring behavior and elevates stress hormone levels. Also, regardless of when consumed, the HFS diet increases novelty reactivity, a risk factor for depression and addiction.

The relationship between the Mediterranean diet and Axis I disorders: A systematic review of observational studies

Axis I disorders are one of the major health burdens worldwide. Evidence suggests that Mediterranean diet has key biological factors associated with reducing the progression of these disorders. This systematic review aimed to clarify the relationship between Mediterranean diet and Axis I disorders. PubMed and Scopus databases were searched from January 2016 up to June 2021. Those observational studies in English language that assessed the relationship between Mediterranean diet and Axis I disorders (such as depression, anxiety, eating disorders, schizophrenia, etc.) were included in this review. The Newcastle–Ottawa Scale was used to evaluate the quality of studies. Thirty‐six studies (15 cohorts, 19 cross‐sectional, and 2 case–control) met the inclusion criteria. The results revealed that more than two‐thirds of the studies (25 studies, 69.44%) had significant protective relationship between receiving Mediterranean diet and reducing the symptoms or incidence of Axis I disorders. Most studies were performed on depression (29 studies measured depression at least as one of the Axis I disorders), of which 72.41% reported an inverse relationship. There were also 9 studies on anxiety (studies that measured anxiety at least as one of the Axis I disorders), that 77.77% of them observed protective association. Moreover, majority of the studies (25 studies, 69.44%) had high quality, of which 76% found an inverse relationship. In conclusion, it seems that the Mediterranean diet can reduce the symptoms or the occurrence of Axis I disorders (especially depression and anxiety). However, more extensive review studies, particularly with interventional designs, are necessary to prove the result.