How the change in Western diet is affecting our mental health: evidence is getting more compelling

Most people accept that what we eat affects our overall sense of wellbeing: when we eat better, we feel better. But research is increasingly showing that the change in modern diet is contributing to mental health issues in many countries. More and more medical and therapeutic trials and research projects are taking place to find out how and why.

In two generations, the nature of what we eat, certainly in the Western world, has undergone rapid change. The focus for many people now is on convenience not nutrition.

Foods that are highly processed, with far fewer nutrients and laden with calories, are being consumed in ever higher quantities. And food has become big business: companies that peddle convenience foods make billions.

A traditional diet

In recent years, claims that diet can affect our mental health were met by some with scepticism, as science hasn’t yet conclusively proved or disproved the idea. But there is no smoke without a little bit of fire, and studies published so far provide, pardon the pun, food for thought about why we should be eating a more traditional diet.

Traditional diets consisted of different things in different cultures. In some parts of the world, it consisted of plants exclusively; in others, fish and wholegrains were a large part, and in others, meat featured prominently.

But even for those of us who eat healthily (at least most of the time), with plenty of fresh fruits and vegetables – or are making efforts to eat this way – the news can be alarming. The level of nutrients in fruits and vegetables has become severely depleted over recent years due to modern agricultural methods and depletion of soil quality.

Studies into nutrition and mental health

In spite of this worrying trend, there is still benefit to be had in following a diet that sticks as closely as possible to wholefoods. Analysis of 21 studies that the University of Newcastle conducted in Australia showed that a diet consisting fruits, vegetables, wholegrains and fish provided good defence against depression.

The British Journal of Psychiatry published a study in 2013 that found a correlation, after studying 90,000 Japanese people, of both sexes, between a lower suicide risk and a diet rich in vegetables, fruit, seaweed, fish and soy.

Studies investigating diet and its effect on children and teenagers found that diets with high intakes of sugar, saturated fats, refined carbohydrates and processed foods all lead to poor mental health in young people.

How foods impact on the brain

The brain is still largely unknown to even the world’s most brilliant scientists, but neurologists are starting to understand the biological pathways that underlie depression and other mental health illnesses. One example is the way Omega-3 acids help brain cells communicate with each other. Studies into Omega 3 and the brain are increasingly showing this fatty acid’s link with depression.

A wholefood diet has a high brain-derived neurotrophic (BDNF) quotient, which is good news for attention and concentration levels, and it stabilises moods. A diet high in saturated animal fats has been proven to diminish BDNF to alarmingly low levels, with the resultant effects of lethargy, inability to concentrate and mood swings.

Gluten, which is blamed for just about everything these days and may sometimes not be the culprit it is made out to be, does show up in medical studies for being (at least partly) to blame for mood disorders.

Fruit and vegetables have well-known anti-inflammatory properties, and these help brain chemicals keep emotions stable. A study this year by the Centre for Addiction and Mental Health in Toronto showed an increase in brain inflammation of 30 per cent in people with clinical depression.

The importance of diet in mental health

More studies are being initiated all the time, many now with a focus on the most prized type of scientific evidence, that of controlled trials.

Once these studies are completed and their findings released, there will be a much more indisputable link between diet and mental health. But even now, with the evidence at hand, The Lancet released a statement earlier this year that said diet is “as important to psychiatry as it is to cardiology, endocrinology and gastroenterology”.