What should we eat for a healthy brain?

There’s a huge amount of evidence that eating a balanced diet is an important way of keeping ourselves healthy. What we eat has an impact on the health of our hearts and blood vessels – and this in turn has an impact on our brain health.

As blood is pumped around the body, our vital organs – including the brain – are constantly supplied with the oxygen and nutrients we need to survive. An unhealthy diet can increase the risk of high blood pressure and clogged arteries, both of which can reduce blood flow to the brain. What we eat can also directly impact brain health by affecting the structure and function of brain cells, inflammation and the production of energy in the brain. But what does research show about the different foods we eat and their impact on brain health? And what should a balanced diet look like?

There’s no shortage of claims about different ‘miracle foods’ that will supposedly help your brain and prevent dementia. But in fact, there’s no single food or supplement that will prevent dementia, no matter what you may see in the headlines. In reality, it’s about a healthy balance, with lots of fruits, vegetables and wholegrains. And while foods that are high in sugar or saturated fats don’t have to be off the menu completely, we really should save them as treats for special occasions.

Perhaps the most promising research in this area has looked at the Mediterranean diet. This is something that my team and I are very interested in.

Examining the traditional Mediterranean diet

In recent years, we’ve been trying to understand how a traditional, high quality Mediterranean diet affects the brain.

A traditional Mediterranean diet looks a lot like the NHS Eatwell Guide to a healthy, balanced diet. It includes:

• Lots of whole unprocessed plant-based foods that are high in fibre and full of compounds that support good heart health. This means foods like fruit and vegetables, wholegrains, legumes (peas, beans and lentils), nuts and seeds. Some recent studies have also suggested that berry fruits and green leafy vegetables may be particularly beneficial for brain health.
• The use of olive oil for cooking instead of saturated fats – rapeseed oil is an excellent alternative to olive oil. And herbs and spices to add flavour instead of salt.
• Fish (and in particular oily fish) as the main source of protein, eaten around two to three times a week.

Importantly, red meats (such as beef, lamb and pork) don’t feature too heavily, and nor do sugary treats. A traditional Mediterranean diet also doesn’t include lots of alcohol, although the occasional glass of wine with a meal wouldn’t be out of place.

Oily fish is an important source of omega-3 fatty acids, which are important for brain health. People with vegan or vegetarian diets can buy omega-3 supplements, but these don’t contain all the nutrients that you’ll get from eating fish.

Our research: the MedEx study

Studies have shown that in Mediterranean countries, people who follow this diet tend to have a lower risk of developing dementia. But we know less about its impact for people in Northern Europe, or how it may affect overall brain health. This is why we set up the MedEx study, with funding from Alzheimer’s Research UK.

As part of our research, we looked back at data from a large, long-running study that was first set up to look at cancer risk. Thousands of people aged 40-79 years gave information about their diet, behaviour and health for this study. Crucially, they also took memory and other cognitive (thinking) tests.

We found that those who followed a Mediterranean-style diet performed better on these tests of brain function.

But the main focus of our MedEx study was on helping people adapt their diet. After all, most people already know it’s good to follow a healthy diet and maintain a healthy weight – but lots of us struggle to put this advice into practice.

We recruited 108 people aged 55-74 years, and asked some of them to eat a Mediterranean-style diet for six months. Some of them were also asked to do more physical activity. To help our volunteers stick to their new routines, we provided online support, regular contact with our team, food deliveries and group sessions.

Right now, we’re still analysing and writing up our results. But early signs suggest the trial was a success, helping people to improve not only their diets, but their memory and thinking too.

It’s never too late to make a change

Another important take home message is that it is never too late to start. Even small changes to your diet can have a major effect on not only your brain health but also your overall mood, anxiety and sleep patterns.

The bigger picture

What we eat is heavily influenced by factors such as our knowledge about different foods and access to affordable food. We live in economically challenging times. Much greater efforts are needed to ensure healthy foods are easily available, at a price people can afford. Government, health professionals and our wider communities all need to be part of this discussion. There are no easy answers – but it’s an important topic with huge potential to help more of us protect our incredible brains and live longer, healthier lives.