8 ways the food you eat affects your brain

What is a brain-friendly diet?

Eating a wide variety of fruit and vegetables provides vitamins, minerals and antioxidants that help to nourish the brain and protect it from a form of damage known as oxidative stress.

Research calls out the Mediterranean diet for its benefits to brain health. This involves eating a diet rich in fruit, vegetables, wholegrains, nuts, seeds and healthy oils and fats. This diet is believed to help slow the rate of cognitive decline, lower the risk of cognitive impairment and potentially reduce the risk of dementia.

How does the food I eat affect my brain?

1. Energising carbs

Although the brain accounts for just two per cent of our body weight, it consumes almost 20 per cent of our the energy we get from glucose – this means nutrition is vital.

The preferred source of energy for the brain comes from carbohydrates like wholegrains, vegetables, fruit, rice, potatoes and lactose (the sugar found in milk). These healthy carbs are broken down by the body into glucose, then used by the brain as energy. Without an adequate intake, the brain cannot function correctly – so you may experience brain fog, lack of focus and irritability.

Glucose forms the building blocks of these carbohydrates. As well as fuelling the brain, it helps with the production of the feel-good chemical, serotonin. Serotonin is responsible for balancing our mood and relieving anxiety.

Some scientists believe refined table sugar – the white stuff you add to tea and coffee, and that’s found in biscuits, cakes and confectionery, may produce addiction-like effects in the brain. However, there are mixed views on this with no conclusive evidence to date.

Enjoy wholesome carbs with our recipes for wholemeal wraps with minty pea hummus & beetroot, cod & olive tagine with brown rice, and brown rice tabbouleh with eggs.

2. Foundational fats

Certain fats are crucial to the brain as they form a key component of our cell walls and help nerve cells, called neurons to function. We know approximately 60 per cent of the brain is made up of omega-3 fats and a type called docosahexaenoic acid (DHA) is the most dominant.

Omega-3 fats are found in fatty fish, like salmon and sardines as well as nuts, like walnuts, and seeds such as flaxseed – these are especially important for brain development in the womb and early childhood. Most brain cells are developed before birth and the rest in the first year of life. This means it’s important to include sources of omega-3 fats during pregnancy and early childhood.

There is evidence to suggest that a lack of these fats in the diet may have an adverse effect on cognition and that eating plenty of them may be associated with a reduction in the development and progression of dementia. Despite these encouraging findings, cause and effect has yet to be demonstrated – so again, larger studies are needed before we can determine the exact relationship between the fat we eat and our brain health.

To boost the beneficial fats in your diet, try our recipes for sesame salmon, purple sprouting broccoli & sweet potato mash, grilled aubergines with spicy chickpeas & walnut sauce, and apricot & seed overnight chia.

3. Vital vitamins

B vitamins as well as C, D and E are all essential for brain health and development. Research shows that a diet rich can mean a lower risk of developing cognitive problems later in life.

Vitamins E, C, B1, B6 and B12 play an important role in our nerve cells.

Studies also identified vitamins B, E, C, and D as being important for brain function. What’s more, B group and vitamin C are essential for energy production in the brain.

Try celeriac ribbons tossed with chard, garlic & pumpkin seeds, kale with chana & coconut and spinach, sweet potato & lentil dhal.

4. Mighty magnesium

Magnesium is a mineral that’s found in avocado, spinach, brown rice and nuts, one of its many uses is that it improves neural plasticity, meaning the nerves are more able to adapt and avoid damage. As a result, eating adequate magnesium may improve memory, help to fight stress and depression and be crucial for the production of energy and neurotransmitters.

Enjoy our delicious chickpea, spinach and almond butter bowl or our spicy red lentil chilli with guacamole and rice.

5. Beneficial gut bacteria (probiotics)

It’s widely accepted that there is a two-way communication between our gut and central nervous system. We often refer to this as the 'gut-brain axis', as this describes the link between cognitive and emotional areas of our brain and our gut.

There’s been a lot of interest in the role gut bacteria, known as probiotics, play in the health and function of our brains. It’s believed that probiotics change the processing of information that is strongly linked to anxiety and depression. A small study involving 20 healthy participants found that, compared to those taking a placebo, people who took a probiotic food supplement experienced fewer negative thoughts associated with sad moods. A further study showed that healthy women who ate probiotic-rich yogurt for four weeks had a reduced emotional response when shown photos of people who were fearful, angry or sad.

While these studies are encouraging, they are limited in size and further studies are needed before we can draw any firm conclusions as to how and why probiotics might affect our mood.

Include more fermented foods in your diet with our raspberry kefir overnight oats, homemade kimchi and simple sauerkraut.

6. Breakfast brain boost

Aim to switch cereals and toast for lean proteins and beneficial fats. Adding protein in the form of milk, yogurt, eggs or beans will help manage appetite and provide the essential amino acids (the building blocks) needed for cell growth and brain development. Combining these with beneficial fats, such as those found in nuts, seeds and oily types of fish, like salmon, will be sure to enhance morning – helping you think more clearly and perform better at cognitive tasks.

Try our breakfast egg wraps, superfood scrambled eggs, smoked salmon and lemon scrambled eggs and slow cooker breakfast beans.

7. High hydration

The brain is made up of 80% water, which explains why staying well hydrated is important for us to think clearly. If our hydration drops, even slightly, we can start to feel the effects in the form of headaches, fatigue and poor concentration.

If plain water sounds unappealing try this delicious alternative, our fruit-infused water.

Read more about hydration and how much water you should drink

8. Be careful with caffeine

Caffeine is widely accepted to be one of the most commonly used psychoactive substances worldwide and is found in a wide variety of food and drinks. In small doses, it is a performance-enhancing substance, acting on the central nervous system to delay tiredness and increase alertness. The caffeine found in tea may be beneficial for cognition in older adults, but may be problematic for those who have trouble sleeping.

Human studies have reported better cognitive function amongst tea and coffee drinkers, and a recent analysis of caffeine concluded that it was consistently associated with a lower risk of Parkinson’s disease, depression and cognitive disorders such as Alzheimer’s disease. However, exactly how and why this occurs is currently unclear.

Learn more about caffeine, including how it affects your body.

Enjoyed this? Now read…

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This article was last reviewed on 31^st May 2024 by Kerry Torrens.

Emer Delaney BSc (Hons), RD has an honours degree in Human Nutrition and Dietetics from the University of Ulster. She has worked as a dietitian in some of London's top teaching hospitals and is currently based in Chelsea.

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