Psychiatrists could start prescribing diet

June 28, 2019
/ Nutrition

If you visit a psychiatrist one day in the not-too-distant future, you may be surprised to find that you are given dietary advice.

That doesn’t mean you won’t be given counselling, and medication where necessary, but it reflects a growing awareness about the importance of nutrition for good mental health.

In fact, some psychiatrists are already doing this, like Dr Drew Ramsey in the US, who regularly prescribes his clients a diet high in fresh, nutritious food and low in highly processed food.

Why does nutrition matter?

Research on links between diet or nutrition and mental health has steadily grown over the past decade or so. This comes from a combination of studies investigating single nutrients and whole diets.

A whole array of nutrients is essential for brain function. Accordingly, research has found that supplementing with nutrients such as vitamins B and D, omega-3, zinc, and magnesium can improve symptoms of depression and anxiety.

Vitamin B and omega-3 may also help alleviate cognitive decline and dementia with aging.

But, although nutritional supplements may be necessary at times, we don’t eat nutrients, we eat whole food. Importantly, interactions between nutrients play important roles in brain function.

Fibre is also critical as it helps to facilitate healthy gut bacteria. This is increasingly recognised as being critical for reducing systemic inflammation and maintaining healthy brain function.

Population studies have consistently shown links between unhealthy diets and higher levels of depression and anxiety, and conversely between healthy diets and better mental health.

It might be said that people who are anxious or depressed eat more poorly, but longitudinal studies also found that people who ate poorly were more likely to develop mental health problems over time.

Other research has shown that people who have higher inflammatory markers in their blood – which underlie a range of chronic diseases – are more likely to become mentally ill.

And diet is a key contributor to low-lying inflammation.

More recently, two randomised controlled trials have confirmed what population research has found. Both were conducted in Australia independently finding that diet substantially reduced depressive symptoms in people suffering major depression.

What diet?

The quick answer: a diet high in fresh food and low in processed food. Like Michael Pollan famously said: “Eat food. Not too much. Mostly plants.”

The traditional Mediterranean diet is high in plant foods – including fruit, vegetables, legumes, nuts, seeds, and whole grains, and includes generous amounts of extra virgin olive oil for salads and cooking (it has a high smoke point so is safe for cooking over moderate heat).

It contains moderate amounts of fish, dairy, and red wine with meals, and little or no meat, highly processed foods and confectionary.

There is endless scope to experiment with this type of diet, which is deceptively simple, tasty, and cheap.

And you never know, healthy food prescriptions might be subsidised by Medicare one day – US researchers have predicted that subsidising 30% of the cost of healthy foods could prevent nearly two million heart attacks, prevent 350,000 deaths and save $100 billion in health care costs.

Given that physical health and mental wellbeing are intimately related, this remedy be just what the psychiatrist ordered.