Does fruit and vegetable consumption impact mental health? Systematic review and meta-analyses of published controlled intervention studies

Associations between fruit and vegetable (FV) consumption and mental health are suggested, largely from observational studies. This systematic review aimed to identify and summarise all published controlled intervention studies investigating the effects of FV consumption on mental health in adults. Four academic databases (Medline, PsycINFO, PubMed, Web of Science) were searched on 16 September 2022, over all years, for studies that used an intervention design; included FV consumption; included an appropriate non-FV-consumption control; used a validated measure of mental health and were conducted in healthy adults or adults with solely a depressive or anxiety-related condition. Study details were tabulated and combined using meta-analyses. Risk of bias was assessed using the domains of the Cochrane Collaboration. Six studies, enrolling 691 healthy adults and reporting on one or more mental health outcomes, were found. Meta-analyses found small and imprecise effects of FV consumption for: psychological well-being (4 studies, 289 participants) standardised mean difference (SMD) = 0·07 (95 % CI -0·17, 0·30), P = 0·58, I2 = 0 %; depressive symptomology (3 studies, 271 participants) SMD = -0·15 (95 % CI -0·40, 0·10), P = 0·23, I2 = 47 % and anxiety-related symptomology (4 studies, 298 participants) SMD = -0·15 (95 % CI -0·39, 0·08), P = 0·20, I2 = 71 %. Some benefit for psychological well-being was found in change-from-baseline data: SMD = 0·28 (95 % CI 0·05, 0·52), P = 0·02, I2 = 0 %. Risk of bias was high in many studies. Limitations include the consideration only of published studies and stem from the studies found. Given the few, limited studies available and the small size of effects, stronger evidence is needed before recommending FV consumption for mental health.

Associations of overall and specific carbohydrate intake with anxiety status evolution in the prospective NutriNet-Santé population-based cohort

We investigated the association between carbohydrate intake and anxiety evolution within the general-population NutriNet-Santé cohort (N = 15,602; 73.8% female; mean age = 53.8y; mean follow-up = 5.4y). Carbohydrate intake was estimated at baseline from ≥ 2 24-h dietary records. Trait anxiety (STAI-T) was measured once at baseline (2013-2016) and once at follow-up (2020), resulting in 4 groups: "None" = absence of high anxiety (STAI-T > 40 points) at any time point; "Transient" = high anxiety only at baseline; "Onset at follow-up" = high anxiety only at follow-up; "Persistent" = high anxiety at baseline and follow-up. Polytomous logistic regression models revealed that sweetened beverage intake was associated with higher odds of "Transient" anxiety (OR_Q4vsQ1 = 1.11; 95% CI 1.02-1.21). Intake of complex carbohydrates (OR_Q4vsQ1 = 1.12; 1.01-1.25) was associated with higher odds of anxiety "Onset at follow-up." The % energy from carbohydrates (OR_Q4vsQ1 = 1.11; 1.03-1.19), intakes of total carbohydrates (OR_Q4vsQ1 = 1.10; 1.03-1.18) and complex carbohydrates (OR_Q4vsQ1 = 1.09; 1.02-1.17) were associated with higher odds of "Persistent" anxiety, whereas 100% fruit juice intake showed lower odds of "Persistent" anxiety (OR_Q4vsQ1 = 0.87; 0.81-0.94). This prospective study found significant associations between dietary carbohydrate intake and anxiety status evolution among French adults. The findings could help inform dietary interventions aimed at anxiety prevention and management.

Longitudinal correlates of fruit and vegetable consumption with depressive symptoms among middle-aged and older adults in South Africa

BACKGROUND

Fruit and vegetable intake may influence mental well-being. The aim of this study was to assess longitudinal associations between fruit and vegetable intake and depressive symptoms among rural South Africans.

METHODS

This longitudinal community study enrolled 3,891 adults (≥ 40 years) from the "Health and Ageing in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI)". Fruit and vegetable intake was assessed by self-report at wave 1, and depressive symptoms were assessed using the Center for Epidemiological Studies Depression Scale at wave 1 and 2. Outcomes were incident and persistent depressive symptoms at wave 2. Logistic regression was used to assess the associations between fruit and vegetable intake at wave 1 and incident, and persistent depressive symptoms.

RESULTS

Results indicate that in the fully adjusted model for individuals with no depressive symptoms at baseline, we found no significant association between frequency of fruit or vegetables intake and incident depressive symptoms. We also found no significant association between frequency of fruit or vegetable intake and persistent depressive symptoms.

CONCLUSION

Fruit and vegetable intake was not significantly associated with incident and persistent depressive symptoms.

The association between major dietary patterns and severe mental disorders symptoms among a large sample of adults living in central Iran: Baseline data of YaHS-TAMYZ cohort study

Background

The diet’s role in developing psychological disorders has been considered by researchers in recent years.

Objective

To examine the association between major dietary patterns and severe mental disorders symptoms in a large sample of adults living in Yazd city, central Iran.

Methods

This cross-sectional study used the baseline data of a population-based cohort study (Yazd Health study: YaHS). Dietary intakes were assessed by a multiple-choice semi-quantitative food frequency questionnaire (FFQ, Yazd nutrition survey called TAMYZ). Psychological assessments were also done by using the depression, anxiety, and stress scale-21 (DASS-21) questionnaire. Major dietary patterns were identified using principal component analysis (PCA). Analysis of covariance (ANCOVA) and logistic regression analyses were used to evaluate the relationship between dietary patterns and mental disorders symptoms.

Results

A total of 7574 adults were included in the current analysis. Four major dietary patterns were identified: "Sugar and Fats”, “Processed Meats and Fish”, "Fruits" and “Vegetables and Red Meat”. After adjustment for all confounding variables, participants in the fifth quintile of “Fruits” dietary pattern which was highly correlated with dried fruits, canned fruits, fruit juice, olive, hydrogenated fats and fruits intake, had a lower odds of severe depression (OR=0.61, 95% CI: 0.45–0.81, p for trend=0.057), anxiety (OR=0.64, 95% CI: 0.50–0.80, p for trend=0.007), and stress, (OR=0.45, 95% CI: 0.30–0.68, p for trend=0.081).

Conclusions

The intake of a dietary pattern high in dried fruits, canned fruits, fruit juice, olive, hydrogenated fats, and fruits might be inversely associated with depression, anxiety, and stress symptoms. Future prospective studies are needed to warrant this finding.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13518-w.

Fruit and Vegetable Intake and Mental Health in Adults: A Systematic Review

The role of a properly balanced diet in the prevention and treatment of mental disorders has been suggested, while vegetables and fruits have a high content of nutrients that may be of importance in the case of depressive disorders. The aim of the study was to conduct a systematic review of the observational studies analyzing association between fruit and vegetable intake and mental health in adults. The search adhered to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and the review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42019138148). A search for peer-reviewed observational studies published until June 2019 was performed in PubMed and Web of Science databases, followed by an additional manual search for publications conducted via analyzing the references of the found studies. With respect to the intake of fruit and/or vegetable, studies that assessed the intake of fruits and/or vegetables, or their processed products (e.g., juices), as a measure expressed in grams or as the number of portions were included. Those studies that assessed the general dietary patterns were not included in the present analysis. With respect to mental health, studies that assessed all the aspects of mental health in both healthy participants and subjects with physical health problems were included, but those conducted in groups of patients with intellectual disabilities, dementia, and eating disorders were excluded. To assess bias, the Newcastle-Ottawa Scale (NOS) was applied. A total of 5911 studies were independently extracted by 2 researchers and verified if they met the inclusion criteria using a 2-stage procedure (based on the title, based on the abstract). After reviewing the full text, a total of 61 studies were selected. A narrative synthesis of the findings from the included studies was performed, which was structured around the type of outcome. The studies included mainly focused on depression and depressive symptoms, but also other characteristics ranging from general and mental well-being, quality of life, sleep quality, life satisfaction, flourishing, mood, self-efficacy, curiosity, creativity, optimism, self-esteem, stress, nervousness, or happiness, to anxiety, minor psychiatric disorders, distress, or attempted suicide, were analyzed. The most prominent results indicated that high total intake of fruits and vegetables, and some of their specific subgroups including berries, citrus, and green leafy vegetables, may promote higher levels of optimism and self-efficacy, as well as reduce the level of psychological distress, ambiguity, and cancer fatalism, and protect against depressive symptoms. However, it must be indicated that the studies included were conducted using various methodologies and in different populations, so their results were not always sufficiently comparable, which is a limitation. Taken together, it can be concluded that fruits and/or vegetables, and some of their specific subgroups, as well as processed fruits and vegetables, seems to have a positive influence on mental health, as stated in the vast majority of the included studies. Therefore, the general recommendation to consume at least 5 portions of fruit and vegetables a day may be beneficial also for mental health.