Eating yourself happy

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Photo of smiling woman with title Prof Jenny Firman AM

When I was a child I was often told to eat my fish dinner with the encourage­ment that fish was brain food. I usually thought this was just a trick to get me to eat something I didn’t like very much. Now we know that fish contains omega fatty acids that are good for our brains. My mother, of course, knew best.

Veterans’ Health week this year was themed around ‘eating well’. I know this comes up again and again in articles on keeping well and living longer but science is bringing new information to light all the time around the link between what you eat and your health, including mental health.

Science is increasingly recognising the link between food and the brain. This can be through sufficient energy for the brain – the brain uses 25% of our energy requirements each day – or through micronutrients needed for the brain’s neurotransmitters to function adequately. There is also much interest in the effect of the gut micro­biota on the brain.

Unfortunately, in Australia the number of peo­ple eating the recommended amounts of fruit and vegetables is low. The Australian Bureau of Statistics reported in its 2020–21 Dietary behav­iour report that, of people aged 18 years and over, only 6.1% met both the fruit and vegetable recom­mendations in the Australian Dietary Guidelines with 9.0% of women meeting both recommen­dations compared to 2.9% of men. In the same period, the National Study of Mental Health and Wellbeing found one in five people (21.4% or 4.2 million) had a mental health disorder in the pre­vious 12 months while 7.5% (1.5 million people) had an affective disorder such as depression.

The Mediterranean diet is recognised as having good benefits for your health. This is a diet high in vegetables and fruits, whole grains, beans, nuts and seeds with olive oil as an important source of fat. Large studies have shown this reduces the risk of heart attack and stroke as well as reduc­ing mortality from cardiovascular disease. It has been associated with a decreased incidence of Parkinson’s disease, Alzheimer disease and many cancers.

Increasingly the Mediterranean diet is also being shown to be beneficial to mental health. The Royal Australian and New Zealand College of Psychiatrists recognises the impact of diet on mood disorders and psychological wellbeing in their recently updated Clinical practice guide­lines for mood disorders. Conversely a diet high in red and/or processed meat, refined grains, sweets, high-fat dairy products, butter, potatoes and high-fat gravy, and low intakes of fruits and vegetables is associated with an increased risk of depression.

Australian researchers have studied the effect of the Mediterranean diet on depression – the SMILES Trial. They conducted a randomised trial on people with moderate to severe depres­sion. One group took part in seven clinical dietician sessions on the Mediterranean diet while the other had seven sessions of social sup­port. Participants were commonly also receiving antidepressant medication or psychotherapy. The researchers measured depression symp­toms and found that the dietary support group demonstrated significantly greater improvement than the social support control group at the end of 12 weeks: a third of those in the dietary sup­port group met criteria for remission of major depression, compared to 8% of those in the social support group.

The Mediterranean diet has also been shown to reduce frailty and loss of independence asso­ciated with aging. While many people take supplements such as omega 3 fatty acids and vitamin D, evidence to date shows that taking supplements alone are not effective at reducing frailty. The mixture of vitamins and nutrients in the largely plant-based Mediterranean diet along with olive oil, whole grains, fish and nuts does provide these required protective ingredients. This is a relatively inexpensive diet and can be supplemented by home-grown vegetables. I am sure there are many veterans who took a keen interest in gardening during COVID. Growing your own vegetables combines exercise in an outdoor setting with the benefits of fresh vegeta­bles in your diet – all good for your mental health.

There are lots of opportunities for Australians to improve their diet and this can have benefits for their mental health. There is no shortage of excellent online resources including recipes and meal plans – see below. If you want to dis­cuss your diet in detail and receive personalised advice, your GP can refer you to a dietician. Your GP can also refer you to a dietician, for a limited number of sessions, as part of a comprehensive treatment plan for a mental health condition.

So switching to the Mediterranean diet can mean you can live longer and feel happier.

Online resources

Food & Mood Centre

Royal Australian College of General Practitioners

Queensland Health website