Diet and Depression

Martina Watts, who both organised and spoke at this conference, reports.

Last year Sustain and the Mental Health Foundation reported that dietary changes may be one of the driving forces behind the rising tide of mental health problems. Click here to read the report.

Depression has increased twenty-fold since 1945 and, according to the World Health Organisation, is set to become the second highest cause of the global ‘disease burden’ by 2020.

Intensive farming and the way our food is stored have altered the balance of nutrients in food thereby potentially affecting the structure and functioning of the brain.

Modern diets are at odds with that of our hunter-gatherer ancestors, who depended on good ‘brain food’ to survive. In the UK, we eat only small amounts of a few types of fruit and vegetables, few wholegrains and little oily fish - but vast quantities of refined carbohydrates, altered fats, intensively reared meat and dairy products, and unknown combinations of synthetic chemicals.

A well attended Pavilion conference examined the latest scientific evidence on how diet, lifestyle and environment influence mood and behaviour and suggested cost-effective diet and lifestyle interventions to be used alone or in conjunction with drug treatments.

No cure - but some help

Dr Andrew McCulloch, chief excecutive of the Mental Health Foundation, admitted there is little clinical evidence that diet can prevent or cure mental health problems. However, in practice, a nutritious diet may relieve the symptoms of mental illness, reduce the side effects of antidepressants and improve their effectiveness.
A Mood and Lifestyle Clinic at Doncaster and South Humber NHS Trust recently found that exercise and diet were as effective as anti-depressants. A high intake of essential fatty acids (EFAs) appears to be protective and treatment with micronutrients (folate, zinc, vitamins B1, B2 and C) helpful.

Andrew suggested that it is time nutrition becomes a mainstream component of mental health care. Diet needs to be a factor in the life style assessment of people with mental illness and services should routinely provide dietary advice.

Link between fish eating and depression

Consultant dietitian, Dr Lynn Harbottle explained the link between low intakes of fish and high levels of depression and suicide worldwide.

Studies suggest that those with depression have lower levels of omega 3 fatty acids in their blood, and may improve if the essential fatty acid EPA is given together with an antidepressant. A one gram dose has been shown to give the best result; giving more has not been found helpful. However, Lynn warned that studies in genetics suggest that although fish oils can have an anti-inflammatory effect for some, for others the effect may be pro-inflammatory. She also advised that cod liver oil should be avoided as it is high in vitamin A which is toxic in high doses. Furthermore, many commercial fish oils are contaminated with marine pollutants.

Many people who are depressed tend to eat diets high in sugar and stimulants and low in nutrients. The advice was for regular oily fish intake (2-4 portions per week) and to choose purified, vitamin A free supplements.

In addition, a healthy diet with baseline nutrients is required, otherwise omega 3 supplementation might do harm rather than good.

Mental health and immune function

The keyspeaker, Michael Ash, nutritionist and founder of the Eldon Health Clinic, explained that depression occurs more frequently in those with medical conditions associated with immune dysfunction.

Our brain and immune system talk to each other constantly using specialised ‘cell-messengers’ called cytokines which come in two varieties: pro-inflammatory and anti-inflammatory.

Researchers found that consistently raised levels of pro-inflammatory cytokines cause lack of energy, appetite suppression, sleep disturbances, changes in mood and loss of interest. If their body cannot produce appropriate anti-inflammatory cytokines to restore the balance when under psychological stress or physical threat (virus or bacteria) some people may develop depressive episodes.
This type of depression is not just a reaction to the illness, but is caused by cytokines provoking an immune system that has lost its ability to return to a state of neutrality. Anti-depressant drugs may further inhibit the production of these crucial anti-inflammatory cytokines.

Michael believes that one reason for the increase in depressive disorders may be a failure to develop a fully functional mucosal immune system in the gut and colon, possibly as a result of exposure to antibiotics at an early age. Nutritional programmes that influence cytokines are new but show considerable promise.

Trace elements, mood and behaviour

Conference chair, Dr Neil Ward, senior lecturer in chemistry at the University of Surrey, explained the impact of trace elements on mood and behaviour.

Deficiencies in selenium, zinc and chromium are commonplace and may play an important role in mood disorders. Toxic elements, such as aluminium, cadmium and lead have long been associated with anti-social behaviour.

In addition, toxic metals block the utilisation of essential trace elements such as calcium, iron, magnesium and zinc, which are required for normal brain and immune system development.

Exercise, green space and mental health

Jo Peacock from the University of Essex’s Green Exercise programme explained the synergistic health benefits of participating in physical activities whilst being directly exposed to nature and green space.
Even short exposure was shown to lower blood pressure, reduce anger, depression and tension and increase self-esteem and mood.
We need to improve accessibility to ‘green exercise’ for all social groups but especially those suffering with ill-health. Added benefits would include reduced public health costs and conservation of our natural resources.

Putting it into practice

In my own practice I have found that depressed clients respond well to a healthier lifestyle, diet and supplements. Devising an individual nutritional programme whilst improving digestive function and efficiency is key, but can only work if clients have the motivation to carry out the programme.

If a family member or friend is present during consultations (and at home) to help with shopping and cooking, this task is made much easier. Effective nutritional intervention includes building practical cooking skills and explaining how digestion works (the importance of gastric juice, probiotics etc). A free weekly phone-in also helps the therapist to pick up on potential difficulties.

The ‘take-home’ message

The dietary message is: more variety, traditional cooking methods and unprocessed, fresh, local, seasonal food high in nutritional value. Weeding out caffeine, nicotine, alcohol, sugar, hydrogenated fat and additives is best done step-by-step. Clients may find this easier if healthier items are introduced consistently, leaving less room for ‘unhealthy’ ones.

Food intolerances, hormone imbalances, dehydration, blood sugar issues, compromised gut immunity, increased essential fatty acid, amino acid or micronutrient requirements, toxic metals or chemical sensitivities are all risk factors and need to be addressed. For some clients, lab testing is useful, for others it is either unnecessary or not financially viable.

The challenge for the nutritional therapist remains effective intervention in difficult circumstances. This would surely be easier if we were part of an integrated team. One delegate suggested diet and green exercise should routinely be handed out ‘on prescription’! We wish!

Martina Watts is a nutritional therapist, health writer and nutrition consultant for schools, local government and the NHS.
For more information check

First Published in 2007

Click here for more articles

Back to top