It’s a no-brainer: diet affects mental health

April 26, 2019
/ Cognition, Nutrition

Recognition of links between diet and mental health has snowballed in recent years. This includes the impact of nutrition on risk of dementia and Alzheimer’s disease.

Some individual nutrients have been singled out, such as vitamin B6 and omega-3. While these are important, by themselves they are no replacement for healthy dietary patterns.

In particular, the Mediterranean diet has been showered with accolades for its physical and mental health benefits.

Not just another organ

Most people won’t argue with the fact that a healthy diet can ward off heart disease, diabetes, obesity and other chronic lifestyle ailments.

Not so many connect diet with mental health. But the brain is an organ, just like the heart, the liver and the pancreas.

It’s not just any organ. Although the brain accounts for only 2-2.7% of the body’s weight, it uses up 25% of the body’s glucose supply at rest – and this increases to 50% when it’s active.

As such, the brain is highly dependent on a regular supply of energy and nutrients from food. This fuels its structure and function, keeping us sharp and happy.

From gut to brain

Not only does the brain need nutrients to work properly and create the neurotransmitters that keep it ticking over, it is directly influenced by signals from the gut through pathways known as the ‘gut-brain axis’.

These pathways are hormonal, neuronal and immunological. And there are trillions of little workers that help or hinder gut-brain messages: microscopic bacteria that dwell in the intestines.

These microbial communities are impacted by several factors including antibiotics, stress and excessive hygiene. They are also influenced by the food we eat.

Specifically, a diet high in sugar and processed food breeds less healthy bacteria while the beneficial microbes munch and proliferate on a whole food, high fibre diet.

Which diet?

There isn’t just one Mediterranean diet. Likewise, populations that live long healthy lives – with miniscule risk of dementia – have variations in their diets.

But there is no need for confusion; some basic underlying dietary principles are simple to follow.

The driving tenet is eating plenty of plant foods: fruit, vegetables, legumes, nuts, seeds and wholegrains. These are teeming with nutrients, antioxidants and fibre that promote a healthy gut and brain.

Fats are also important. In particular, extra virgin olive oil – a healthy monounsaturated fat – has numerous benefits attributed to its antioxidant properties. This oil has a high smoke point so can be used liberally for cooking as well as salads.

The diet typically includes moderate intakes of fish, which is associated with reduced risk of dementia, fermented dairy and red wine with meals. Importantly, it is low in sugar, processed foods and meat.

Nurturing a healthy lifestyle not only includes following these dietary principles; engaging in regular physical activity is also robustly linked to better physical and cognitive outcomes with aging.