My research shows that eight everyday foods can help protect our brain health as we age. Here’s what to put on your plate.

1. Oily fish

If you do only one thing for your brain health, eat more oily fish. It gives you the biggest return for the least effort, yet most of us don’t eat nearly enough.

Salmon, sardines, mackerel and other oily fish are the richest source of DHA (docosahexaenoic acid), an omega-3 fatty acid that forms a key structural building block of the brain. Without that support, all the other nutrients are feeding a brain that is not functioning at its best.

Your body can only make small amounts of DHA, so dietary sources are essential. Maintaining a good supply throughout life may help keep the brain more resilient as we age. A study in the American Journal of Preventive Medicine found fish eaters had larger brain volumes, particularly in areas linked to memory and cognition.

Smaller oily fish such as sardines, anchovies and mackerel are best, as they’re lower in contaminants, nutrient-dense and affordable. A tin of sardines a week provides enough DHA (325-350mg) to replace losses, with calcium and vitamins B and D.

I recommend eating oily fish at least twice a week. If you don’t eat fish, consider an algae-based omega-3 supplement. DHA originates in marine microalgae, which fish consume, and it’s often less contaminated.

2. Berries

A daily handful of berries is one of the simplest ways to protect your brain as it ages.

Berries are rich in flavonoids, particularly anthocyanins – the pigments that give them their deep red, blue and purple hues. These compounds improve blood flow to the brain, helping your brain cells get more oxygen and nutrients.

Our research here at Reading shows eating one to two portions (80 to 160g) of berries can boost cognitive performance within just a few hours. If you’re doing a complex task, it can really help, even if you’re not consciously aware of it.

But flavonoids have longer-term benefits, too. They can help brain cells become more resistant to age-related stress. A 20-year Harvard study tracking more than 77,000 middle-aged people found those who ate the most flavonoid-rich foods were 20% less likely to report memory problems as they aged.

Shop with your eyes – the brightest-coloured berries tend to contain the highest concentrations of beneficial compounds. Blueberries, blackberries and strawberries are all good options, and frozen berries are just as beneficial, and cheaper.

I add berries to my breakfast oats or have them for dessert with other fruits. One tip: avoid eating them with banana. It contains an enzyme called polyphenol oxidase, which destroys some of the beneficial compounds.

3. Cocoa

If berries are the number-one food for boosting blood flow to the brain, cocoa comes a close second. It contains another group of flavonoids called flavanols, which have some of the strongest evidence of any brain food.

A major study of more than 21,000 older adults, the COSMOS trial, found cocoa flavanols improve blood flow to the hippocampus – a part of the brain involved in short-term memory and one of the main regions affected in Alzheimer’s.

People hear “cocoa” and think any dark chocolate will do, but it’s not that simple. Many of cocoa’s beneficial compounds are destroyed when it’s heavily processed, so if you’re buying dark chocolate, it’s not just about a high cocoa percentage – the less processed, the better. Look for “raw cocoa” and a short list of ingredients. You want that bitterness, which is a good sign you’re getting the beneficial compounds.

Raw cacao powder is another good option. Try stirring it into porridge, yoghurt or smoothies. You don’t need huge amounts to get the benefits. Around 10 to 50g of unprocessed cocoa powder can provide a good dose.

Apples, grapes and tea also contain flavanols, so you don’t need to rely on chocolate alone.

4. Eggs

The humble egg contains all the nutrients needed to build a healthy brain.

Egg yolks are one of the richest sources of choline, a nutrient that helps create healthy brain cell membranes and produce acetylcholine, which is a neurotransmitter involved in memory, learning and concentration.

Research suggests people with higher intakes of choline tend to perform better in memory tests. A study published in the American Journal of Clinical Nutrition found a low choline intake was associated with a higher risk of Alzheimer’s disease and dementia.

Egg yolks also provide DHA, B vitamins and minerals such as iron and zinc, all of which play an important role in brain function.

I recommend eating four to six eggs a week. One recent study, in the Journal of Nutrition, found eating at least five eggs a week was associated with a 27% lower risk of Alzheimer’s.

Whatever you do, don’t ditch the yolk – it’s where many of the brain-friendly benefits lie.

5. Oats

I always start the day with a bowl of oats – it’s one of the best ways to support brain energy and cognitive function.

The brain is one of the most active organs in the body, so it needs a constant fuel supply to perform. Wholegrains such as oats, wholemeal bread and brown rice provide a combination of B vitamins, fibre and slow-release carbohydrates that help fuel the brain steadily throughout the day, rather than sending blood sugar on a roller coaster.

Always choose whole, rolled oats rather than instant varieties. When grains such as wheat and rice are heavily processed, much of the fibre is stripped away, leaving mainly starch. This can trigger glucose spikes and crashes, which may contribute to insulin resistance and inflammation, both of which are linked to cognitive decline.

A 12-year study of almost 3000 adults published in The Journal of Prevention of Alzheimer’s Disease, found people with the highest wholegrain intake were around 36% less likely to develop Alzheimer’s disease than those eating the least.

6. Leafy green veg

A daily serving of greens could help protect your memory as you age.

Spinach, kale, chard and other varieties of leafy green veg contain dietary nitrates, which are converted in the body into nitric oxide – a compound that widens blood vessels, lowers blood pressure and improves blood flow to the brain.

This ensures a better supply of oxygen and nutrients to your brain cells, and allows them to function more efficiently. A five-year study of older adults published in the journal Neurology found eating one serving of green leafy veg a day was associated with slower age-related cognitive decline.

To preserve the benefits, prepare your greens carefully. Nitrates are water-soluble, so they can leach out during cooking. Steaming, stir-frying or eating greens raw in salads preserves more of the compounds than boiling. Try spinach folded into an omelette, kale grated into coleslaw or chard stirred into soups.

7. Pulses

Packed with B vitamins, fibre and slow-release carbohydrates, pulses support steady brain energy while also feeding the gut microbiome – something we now know plays an important role in healthy brain ageing.

When fibre reaches the gut, beneficial bacteria break it down into compounds called short-chain fatty acids. These help support the blood-brain barrier (the brain’s protective shield) while reducing inflammation, both of which play a role in cognitive decline and dementia risk.

Aim for at least three portions a week. Add beans to soups and stews, toss chickpeas into salads or stir lentils through pasta sauces and curries.

8. Green tea

Tea is a bit of a bonus food – it combines a few brain-friendly benefits in one cup.

Alongside caffeine, tea contains L-theanine, an amino acid that sharpens memory and attention while promoting a calmer, more focused state versus the jittery burst you get from coffee.

Green tea is best because it’s particularly rich in flavanols, the plant compounds that improve brain blood flow. A review of studies published in Oncotarget found each additional daily cup of green tea was associated with a 6% lower risk of cognitive decline.

Aim for a couple of cups of tea a day. I make mine quite strong – three tea bags or two big teaspoons of green tea powder.

Dr Jeremy Spencer is Professor of Nutritional Biochemistry and Medicine at University of Reading.

As told to Mary Comber