In recognition of a month focused on mental health and wellbeing, we investigated the intriguing findings that suggest plant-based diets may help improve mental health. The following blog has excerpts from Dr Shireen Kassam and Dr Zahra Kassam’s book ‘Eating Plant Based’, which you can find here.
Wellbeing and Fruit & Veg
High psychological wellbeing is more than the absence of mental illness. It is a sense that we are functioning well in our life. People with high psychological wellbeing also report feeling capable, well-supported, and satisfied with life and are more likely to live healthier and longer lives. Accumulating data now show that PBDs, or simply increasing fruit and vegetable (FV) consumption, are associated with gains in wellbeing.
Worldwide Studies
A study that used data on over 45,000 individuals followed over time, found that wellbeing increased in a dose-response fashion with the number of portions of FV consumed or with the frequency of FV consumption. Even modest increases in FV intake had substantive positive effects on wellbeing.
Similarly, a novel 2-week study in New Zealand showed that providing high-quality FV to young adults resulted in short-term improvements in mental wellbeing, specifically vitality, flourishing, and motivation. Consumption of raw FV may also be important in optimising better mental health wellbeing, with a high level of correlation with consumption of carrots, bananas, apples, leafy greens, citrus fruits, fresh berries, cucumber, and kiwi fruit in one study.
In another longitudinal study of over 12,000 Australian adults, increased FV consumption was predictive of increased happiness, life satisfaction, and wellbeing. The gain was up to 0.24 life-satisfaction points (for an increase of eight portions a day), which is equal in size to the psychological gain of moving from unemployment to employment.36 In a systematic review of 30 studies examining the association between FV consumption and general (broad) mental health in women, a positive influence of FV was seen using measures of wellbeing, quality of life, positive and negative affect, self-esteem, anxiety, distress, depressive symptoms, depression, and suicide.
Wellbeing, Diet and Diabetes
Wellbeing and diet have also been studied in the context of type 2 diabetes. Diabetes has significant co-morbidity with depressive illness, which itself places high demands on the individual’s inner resources. A large longitudinal study of patients with diabetes has shown improved outcomes for 5-year mental health and wellbeing associated with higher intakes of FV and specifically FV-derived dietary fibre and resistant starch, such as that found in cereals and whole grains. A systematic review of 11 controlled trials concluded that a plant-based diet can significantly improve psychological wellbeing and quality of life in people with type 2 diabetes. The studies included were conducted in several different countries suggesting broad clinical applicability. Specifically, PBDs were associated with significant improvement in emotional wellbeing, physical wellbeing, depression, quality of life, general health, pain perception, weight, diabetes control and lipids, compared with several diabetes associations’ official guidelines and other comparator diets.
Nutrition and Mental Health in Children
In children and adolescents, a systematic review of 12 epidemiological studies reported a significant relationship between unhealthy dietary patterns (including higher intake of foods with saturated fat, refined carbohydrates and processed food products) and worse mental health.40 They also observed an association between good quality diet and better mental health. Since mental disorders often begin in youth, the implications are far-reaching.
A worksite-based pilot study using a whole food plant-based diet intervention resulted in significant improvements in the psychological subscale of quality of life, alongside other wellbeing improvements and is an early indicator that such interventions are both feasible and effective.
For more information on plant based diets, you can read Dr Zahra Kassam and Dr Shireen Kassam’s full books ‘Eating Plant Based’ and ‘Plant Based Nutrition in Clinical Practice’ which provides in depth guidance supported by scientific evidence.
