Nutrition and Mental Health
Canadian statistics cite a 11% chance of developing Major Depressive Disorder in your life, with 4 % of Canadians suffering from major depression in any given year, and 2% of these committing suicide. This does not include the thousands of others suffering from milder forms of depression which still have significant social, emotional and financial costs.
Many people cannot tolerate antidepressants due to side effects, or do not benefit from them. Others are reluctant to take the medication or won’t seek counselling due to the stigma attached to mental illness. As result, they miss on average 19 days work a year, costing employers millions dollars a year in lost productivity.
As part of the Nurses’ Health Study, researchers analyzed the diets of nearly 44 000 women who were free of depression at the beginning of the study and followed them for an average of 12 years. Using proven markers of depression as well as requiring a doctor’s diagnosis confirming the depression and the new use of antidepressants, they found that women who ate more inflammatory food products (those high in meat, fish, sodas and refined grains) were 41% more likely to be depressed.
Vegetarians have a lower incidence of depression -and score significantly better on mood tests which measure depression, anxiety & stress. The vegetarians ate less eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) & arachidonic acid - all animal sources of omega-6 fatty acids, but had higher intakes of plant sources of omega-6 and omega-3. The main sources of arachidonic acid are poultry, eggs and meat. Increased arachidonic acid intake creates pro-inflammatory metabolites which increase inflammation throughout the body and exacerbate joint pain and neuro-inflammation.
A recent study published in American Journal of Health Promotion showed how a plant-based nutrition program improved depression, anxiety, fatigue, productivity and other markers of well-being.
The 18 week study was conducted in a corporate setting with participants being either overweight or having type 2 diabetes. They adopted a low-fat vegan diet which emphasized high fibre, low-glycemic foods. As well as the improvement in their mental health, they lost on average 10 pounds and the diabetics got better control of blood sugars.
SO how does a plant based diet improve depression? Depression has been shown to be related to excess inflammation in the body and to low levels of serotonin. Plant based foods naturally lower inflammation, being lower in fat and high in antioxidants. Also, high intake of veggies increases the amount of B vitamins in the diet, which has also been shown to positively impact moods.