Wellbeing & Veganism: Eating vegan for mind and mood (Part 1)

In a special three-part series for our new wellbeing research programme, Researcher Network member, Laura Grimes looks at the literature on mental health and veganism and considers how a variety of different lifestyle factors contribute to positive mental wellbeing. However, she asks, where does a vegan diet fit into this?

Mental health has never been a more relevant or topical subject, especially in the midst of a global pandemic. With one in four of us reportedly experiencing a mental health problem each year (1) research into those lifestyle choices which both positively and negatively impact upon mental wellbeing have never been more timely. If we can make educated choices to improve our mental and physical health then we are moving towards a knowledge base that can help us work to improve our quality of life.

Mental health and wellbeing is a wide-ranging scale which begins with the positive indicators of mental wellbeing (2) and reaches to the other end of the scale to include mental health disorders such as anxiety disorders, clinical depression and obsessive-compulsive disorder amongst others. Research suggests a variety of different lifestyle factors contribute to positive mental wellbeing, but where does a vegan diet fit into this?

The picture to date is mixed, with some evidence presenting both positive and negative links between mental health and a vegan diet.  One study found that lower levels of anxiety in males were related to a vegan diet and improved daily fruit and vegetable intake, whilst lower stress scores in females were related to a vegan diet and lower intake of sweets. Overall here it was suggested that a reduction in animal foods and products may have mood-enhancing benefits (3).  Meanwhile, an observational study exploring changes in quality of life, anxiety, stress and immune markers in participants staying at a raw vegan institute for between one and three weeks found quality of life improved by 11.5%, anxiety levels decreased by 18.6% and perceived levels of stress also decreased by 16.4% (4).  If we look a bit further than this, a vegan diet has also been shown to positively impact upon the symptoms of Fibromyalgia – a condition characterised by symptoms such as sensitivity to touch, stiffness, fatigue, and problems with cognition including mental health symptoms such as depression and anxiety (5), whilst research demonstrated improvements in sleep quality, general health and body mass index (BMI) which did in the short-term at least improve overall symptoms of fibromyalgia (6).

So it seems that a vegan diet may at least contribute to improved mental wellbeing, but where does this come from?  Is it a simple ‘one-size fits all’ mechanism or can it be sourced back to the ability of diet to regulate our pathophysiology and therefore also our neuropsychological functioning? 

Cholecystokinin (CCK) is a digestive hormone released within the small intestine when fats and proteins are ingested and acts as a transmitter in central and intestinal neurons (7).  CCK can also be used experimentally to induce panic and bolus injections have been shown to increase the levels of circulating stress hormones which can produce panic attacks (8).  We know that a vegan diet that is rich in plant-based foods is often lower in fat content compared with that of omnivores (9) and therefore lower levels of this hormone should be secreted in vegans compared to omnivores, supporting the finding that vegans experience reduced levels of anxiety compared to those consuming a diet with higher levels of processed meats (which contain higher levels of processed fats and proteins).  Furthermore a vegan diet is often higher in fibre compared to omnivores which can slow the movement of food in the gut and result in a reduction upon the secretion of CCK and other gut neurotransmitters (10).

Where this has presented a wealth of evidence supporting the benefits of a vegan diet to mental health and wellbeing and some of the supporting explanations behind it, it is important to note that there is evidence to the contrary also.  A vegan diet has not always been linked to better mental health and next month the second installment will be looking at the literature against the supporting evidence and examines some of the reasons as to why this might be. 

The second part of Eating vegan for mind and mood: An evidence-based look at mental health and veganism will be published next month.

Comment from Heather Russell, The Vegan Society's in-house Dietitian:

“We know that an adequate supply of essential nutrients and a healthy vascular system are important for looking after our minds. A well-planned vegan diet can provide all the nutrients that our bodies need. It is also rich in minimally processed plant foods like vegetables, fruit, nuts and wholegrains, which are great for vascular health. Although vegan nutrition and brain health has been a popular topic among journalists, the current evidence base is actually pretty limited and further research would certainly be welcome.”

References

The views expressed by our Research News contributors are not necessarily the views of The Vegan Society.