Last updated: October 2026
The best brain foods are the ones that make up a healthy diet overall: oily fish, berries, leafy greens, nuts, eggs, wholegrains and beans, plus enough water. Most of the evidence is observational, and no single food will sharpen your memory on its own. For focus today, regular meals, water and sleep matter most.
Below: each food ranked by the strength of the research, what the MIND diet trial found, nutrients with official brain claims, and what to eat for exams and for kids.
Brain foods at a glance
Most “brain food” lists treat every food as equally proven. They aren’t. Studies that follow what people eat can show links but not cause, because people who eat more fish or berries often live healthier lives in other ways too.
| Food | What the research found | How strong is it? |
|---|---|---|
| Oily fish | Each extra weekly serving linked to about 5% lower dementia risk (21 studies). Omega-3 capsules didn’t help in trials | Consistent links for the food; capsules disappointing |
| Berries | Most blueberries and strawberries linked to slower memory decline (16,010 older women) | One large observational study |
| Leafy greens | About one serving a day linked to slower decline (960 older adults) | Observational only |
| Nuts and olive oil | Mediterranean diet plus 30g nuts a day protected memory better than a low-fat diet | One randomised trial |
| Eggs | Rich in choline, used to make brain messengers | Indirect only |
| Wholegrains and regular meals | Breakfast, versus none, helped children’s attention and memory that morning | Reasonable for regular meals |
| Cocoa flavanols | No benefit to overall thinking in a large three-year trial | Large trials, mostly negative |
| Coffee and tea | Caffeine improves alertness and attention; memory effects less consistent | Strong for short-term alertness |
| Water | Dehydration can affect some thinking skills and mood | Reasonable, mixed quality |
The whole diet matters more than any one “superfood”. If your main problem is feeling foggy, start with our guide to brain fog.
1. Oily fish and omega-3
Oily fish (salmon, mackerel, sardines, herring, pilchards, trout, kippers) is the classic brain food and the main food source of DHA, a long-chain omega-3 fat.
A 2016 analysis pooled 21 long-term studies covering 181,580 people. Each extra serving of fish a week was linked to about a 5% lower risk of dementia and a 7% lower risk of Alzheimer’s disease.
Capsules are a different story. A Cochrane review of three high-quality trials (3,536 people) found omega-3 supplements gave no benefit to thinking skills in healthy older people. The evidence points to eating fish, not a pill.
DHA is one of the few nutrients with an official brain claim in the UK: DHA contributes to maintenance of normal brain function, with the benefit obtained from 250mg of DHA a day.
How much: the NHS advises at least 2 portions of fish a week, one of them oily, with a portion around 140g. Girls, and women who are pregnant, breastfeeding or may have a baby one day, should have no more than 2 portions of oily fish a week. Fresh and tinned tuna don’t count as oily fish.
2. Berries
Berries are rich in flavonoids, plant compounds that give them their deep colours. In the Nurses’ Health Study, researchers followed 16,010 women aged 70 and over. Those who ate the most blueberries and strawberries had slower memory decline, equivalent to delaying cognitive ageing by up to 2.5 years.
It’s one observational study, so it can’t prove cause. But berries (frozen work just as well) count towards your 5 a day, so add a handful to porridge or yoghurt.
3. Leafy greens
Spinach, kale, cabbage, rocket, watercress and spring greens carry folate, vitamin K, lutein, nitrate and other nutrients. In a study of 960 adults aged 58 to 99, people who ate the most leafy greens (about 1.3 servings a day) declined more slowly over nearly five years, by an amount equal to being 11 years younger.
A link, not proof, but the takeaway is simple: aim for a serving of greens a day. Leafy greens are also good sources of magnesium; see our list of foods high in magnesium.
4. Nuts and olive oil
Nuts have some of the better trial evidence of any single food. In a Spanish trial of 447 older adults at high risk of heart disease, people were randomly given a Mediterranean diet plus 30g of mixed nuts a day, a Mediterranean diet plus extra virgin olive oil, or advice to cut fat. After about four years, memory scores held up better in the nuts group, and the olive oil group did better on attention and overall thinking. Scores fell in the low-fat group.
Only 334 people were retested, but it’s a useful sign that eating patterns can make a difference. A small handful of nuts a day is a sensible habit.
5. Eggs
Eggs are one of the richest everyday sources of choline, which the body uses for cell structure and to make neurotransmitters, the messengers between nerve cells.
That said, there’s no strong trial showing eggs improve memory, and choline’s official health claims in the UK relate to the liver and fat metabolism, not the brain. Eggs also provide iodine and vitamin B12, both covered in the nutrients section below.
6. Wholegrains, beans and regular meals
Going for hours without food is a common reason for flagging focus. Carbohydrates contribute to the maintenance of normal brain function (the benefit comes from 130g of carbohydrates a day from all sources).
The NHS Eatwell Guide says to base meals on starchy foods and choose wholegrain or higher-fibre versions, such as oats, brown rice, wholemeal bread and wholewheat pasta. Beans, lentils and chickpeas add fibre and protein too. A review of 45 studies in children found that eating breakfast, compared with skipping it, helped attention, memory and planning the same morning.
If big lunches leave you sluggish, see why you feel tired after eating. For the 4pm biscuit habit, see sugar cravings.
7. Dark chocolate and cocoa: the honest answer
Cocoa contains flavanols, and “dark chocolate is good for your brain” is a popular claim. The best trials are less exciting.
- COSMOS-Mind gave 2,262 older adults a cocoa extract capsule (500mg of flavanols a day) or a placebo for three years. The cocoa extract had no effect on overall thinking skills.
- COSMOS-Web (3,562 older adults) found no memory improvement overall after a year. Memory did improve in people whose diets were lower in quality or in flavanols to begin with, which suggests topping up a shortfall rather than boosting a healthy brain. Mars, which makes cocoa extracts, part-funded the research.
Both trials used concentrated extracts, not chocolate bars, so a few squares of dark chocolate won’t reproduce them. Enjoy it as a treat. If you like a warm cacao drink, our guide to ceremonial cacao covers the options. We make no brain claims for our own cacao drink, the Reishi Mushroom Adaptogenic Complex.
8. Coffee, tea and caffeine
Caffeine has the clearest short-term effect of anything here. A research review found that low to moderate doses (roughly 40mg to 300mg) improve alertness, attention and reaction time, with less consistent effects on memory and decision-making.
There is no authorised health claim for caffeine in Great Britain. The European Food Safety Authority (EFSA) says up to 400mg a day is safe for healthy adults, single doses up to 200mg, and up to 200mg a day in pregnancy. As a guide, EFSA puts a 200ml cup of filter coffee at about 90mg and a cup of black tea at about 50mg.
If coffee leaves you jittery or flat later in the day, see coffee crash. Tea also contains L-theanine, which is studied alongside caffeine for focus; see L-theanine benefits.
9. Water
A review of hydration research found that dehydration can affect some thinking skills and mood, particularly in children and older people, who regulate fluids less well. The studies vary in quality, but the advice is easy.
The NHS recommends 6 to 8 cups or glasses of fluid a day, more in hot weather or when you’re active. Water, lower-fat milk, tea and coffee all count. Pale yellow pee is a good sign you’re drinking enough.
The MIND diet: does it work?
The MIND diet is a hybrid of the Mediterranean and DASH (blood-pressure lowering) diets, built around the foods most linked with slower brain ageing.
The 2015 study that made it famous followed 923 people aged 58 to 98 for about 4.5 years. Those whose diets matched MIND most closely had about half the rate of Alzheimer’s disease of those who matched it least. This was observational.
The 2023 trial in the New England Journal of Medicine put it to the test. 604 older adults with a family history of dementia, who were overweight and had a less healthy diet, followed either the MIND diet or their usual diet, both with the same mild calorie cutting. After three years, thinking scores improved in both groups, and the difference between them was small and not statistically significant. Brain scans were similar too.
So the MIND diet didn’t beat a calorie-controlled usual diet over three years. The control group probably ate better too, and three years may be too short, but it’s a reality check on any eating plan called “proven” to protect memory. These were the trial’s targets:
| Eat more | Eat less |
|---|---|
| Green leafy vegetables | Red and processed meat |
| Blueberries (about 425g a week) | Butter and margarine |
| Mixed nuts (about 140g a week) | Whole-fat cheese |
| Extra virgin olive oil | Pastries and sweets |
| Fish and plant-based foods | Fried foods |
Nutrients with official brain claims (and where to find them)
In the UK, only claims on the Great Britain nutrition and health claims register can be made about foods. These are the authorised brain and mind claims, and where to find each nutrient.
| Nutrient | Authorised claim | Good food sources |
|---|---|---|
| DHA (omega-3) | Contributes to maintenance of normal brain function (250mg a day) | Oily fish |
| Iodine | Contributes to normal cognitive function | Milk and dairy, eggs, sea fish, shellfish; some fortified plant drinks |
| Iron | Contributes to normal cognitive function | See iron-rich foods |
| Zinc | Contributes to normal cognitive function | Meat, shellfish, cheese, bread, wheatgerm |
| Vitamin B12 | Contributes to normal psychological function and normal functioning of the nervous system | Meat, fish, milk, cheese, eggs, some fortified breakfast cereals |
| Folate, B6, thiamine, niacin, biotin, vitamin C | Contribute to normal psychological function | Folate: leafy greens, broccoli, peas, chickpeas and kidney beans |
| Magnesium | Contributes to normal psychological function | Spinach, nuts, wholemeal bread |
| Carbohydrates | Contribute to the maintenance of normal brain function (130g a day from all sources) | Wholegrains, potatoes, fruit, beans |
Adults need 140 micrograms of iodine a day (NHS); if you avoid dairy, eggs and fish, check your plant milk is fortified. If you feel tired and foggy, low B12 or iron are worth ruling out with your GP; see vitamin B12 deficiency symptoms.
Food comes first, but if you’d like a magnesium top-up, our Magnesium Glycinate Sleep Complex is a caffeine-free evening drink with 148mg of magnesium per serving. Magnesium contributes to normal psychological function and to the reduction of tiredness and fatigue. More in magnesium for focus and brain fog.
What works against your brain
Alcohol
A UK study followed 550 adults for 30 years, then scanned their brains. Those drinking 14 to 21 units a week had three times the odds of shrinkage in the right hippocampus, a key memory area, compared with non-drinkers; light drinking showed no protective effect. The NHS advises no more than 14 units a week, spread over 3 or more days, and lists memory loss among the long-term risks of drinking more.
Ultra-processed food
In UK Biobank, 72,083 people aged 55 and over were followed for about 10 years. Each 10% increase in the share of ultra-processed food in the diet was linked to a 25% higher risk of dementia, and swapping 10% of it for unprocessed or minimally processed food was linked to a 19% lower risk. It’s observational, but it fits the wider picture: meals built from whole foods look better for the brain than ready meals and snacks.
Short sleep
No food can make up for a short night: the NHS notes that good sleep helps thinking and concentration. See sleep deprivation.
Brain foods for studying and exams
There’s no exam-day superfood: what helps is regular food, water and sleep. The NHS says a balanced diet can help young people feel well during exams, that most teenagers need 8 to 10 hours’ sleep a night, and that cramming all night is usually a bad idea.
- Eat breakfast on exam days: porridge with berries, eggs on wholemeal toast, or yoghurt with fruit and nuts.
- Eat regular meals with some protein and starchy carbs, rather than grazing on sweets.
- Pack snacks: fruit, a small handful of nuts (adults and older children), oatcakes with cheese or hummus, or a banana.
- Take a water bottle into revision sessions and the exam if allowed.
- Go easy on caffeine, especially after lunch, so it doesn’t spoil sleep. The NHS notes some parents find high-sugar, high-caffeine foods make children moody.
- Move: the NHS says exercise can boost energy, clear the mind and relieve stress. A short walk between revision blocks helps.
For more on staying on task, see how to focus better.
Brain foods for kids
Children don’t need special brain foods. From age 2, the NHS says they can eat the same foods as the rest of the family, in the proportions of the Eatwell Guide.
- Fish: the NHS suggests at least 1 portion of oily fish a week for young children, with no more than 4 a week for boys and 2 for girls. Children under 16 should avoid shark, swordfish and marlin.
- Breakfast: eating breakfast helps children’s attention and memory the same morning, compared with skipping it.
- Nuts: don’t give whole nuts, including peanuts, to children under 5 because of the choking risk.
- Drinks: stick mainly to water and milk. The NHS says children should avoid sugary fizzy drinks, squash and juice drinks.
- Caffeine: EFSA suggests children and teenagers stay under 3mg per kg of body weight a day, so limit cola, tea and coffee, and avoid energy drinks.
If you’re worried about a child’s concentration, learning or eating, talk to your GP or health visitor. Evopure products are for adults (18+) only, and we don’t recommend them for children.
What about brain supplements?
Supplements can fill a gap, such as B12 for vegans or iodine if you avoid dairy and fish, but they don’t replace food. Omega-3 capsules and cocoa extract didn’t help in the big trials. COSMOS-Mind did find a small benefit from a daily multivitamin over three years, which the researchers said needs confirming.
For a plain-English look at what’s legal and what has evidence, see nootropics in the UK. If you’re curious about mushrooms, our lion’s mane guide covers the early research and its limits. And for how diet links to mood rather than memory, see food and mood.
FAQs
What is the number one brain food?
There isn’t one. Oily fish has the most consistent research, but the strongest message is that the overall diet matters more than any single food: fish, berries, leafy greens, nuts, wholegrains, beans and enough water.
What should I eat before an exam?
A normal breakfast with protein and starchy carbs, such as porridge with berries or eggs on wholemeal toast, plus water. Avoid trying new foods or lots of caffeine on the day, and prioritise sleep the night before.
Which fruit is best for the brain?
Berries have the most research. In a study of 16,010 older women, those eating the most blueberries and strawberries had slower memory decline. Frozen berries work just as well as fresh.
Is dark chocolate good for your brain?
Not as much as headlines suggest. Large trials of concentrated cocoa flavanol extracts found no benefit to overall thinking in older adults, with a memory benefit only in people with poorer diets. Enjoy dark chocolate as a treat.
Does the MIND diet work?
Observational studies linked it to lower Alzheimer’s rates, but a 2023 three-year trial of 604 older adults found no significant difference in thinking or brain scans compared with a usual diet with the same calorie cutting.
Are eggs good for your brain?
Eggs are a good source of choline, iodine and vitamin B12, and make a filling breakfast. There is no strong evidence that eggs on their own improve memory.
What are good brain foods for kids?
The same healthy family diet as adults from age 2: fruit and vegetables, wholegrains, oily fish once a week, eggs, beans and dairy, plus a regular breakfast and water. No whole nuts for under-5s.
Sources
- NHS. Fish and shellfish.
- NHS. The Eatwell Guide.
- NHS. Water, drinks and your health.
- NHS. Iodine.
- NHS. The risks of drinking too much.
- NHS. Help your child beat exam stress.
- NHS. What to feed young children.
- GOV.UK. Great Britain nutrition and health claims (NHC) register (May 2026 version).
- EFSA. Caffeine.
- Zhang Y et al. (2016). Intakes of fish and polyunsaturated fatty acids and mild-to-severe cognitive impairment risks: a dose-response meta-analysis of 21 cohort studies. Am J Clin Nutr.
- Sydenham E et al. (2012). Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database Syst Rev.
- Devore EE et al. (2012). Dietary intakes of berries and flavonoids in relation to cognitive decline. Ann Neurol.
- Morris MC et al. (2018). Nutrients and bioactives in green leafy vegetables and cognitive decline. Neurology.
- Valls-Pedret C et al. (2015). Mediterranean diet and age-related cognitive decline: a randomized clinical trial. JAMA Intern Med.
- Zeisel SH, da Costa KA (2009). Choline: an essential nutrient for public health. Nutr Rev.
- Adolphus K et al. (2016). The effects of breakfast and breakfast composition on cognition in children and adolescents. Adv Nutr.
- Baker LD et al. (2023). Effects of cocoa extract and a multivitamin on cognitive function (COSMOS-Mind). Alzheimers Dement.
- Brickman AM et al. (2023). Dietary flavanols restore hippocampal-dependent memory in older adults with lower diet quality (COSMOS-Web). PNAS.
- McLellan TM et al. (2016). A review of caffeine’s effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev.
- Masento NA et al. (2014). Effects of hydration status on cognitive performance and mood. Br J Nutr.
- Morris MC et al. (2015). MIND diet associated with reduced incidence of Alzheimer’s disease. Alzheimers Dement.
- Barnes LL et al. (2023). Trial of the MIND diet for prevention of cognitive decline in older persons. N Engl J Med.
- Topiwala A et al. (2017). Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline. BMJ.
- Li H et al. (2022). Association of ultraprocessed food consumption with risk of dementia. Neurology.
This guide is general information, not medical advice. If you’re worried about your memory or concentration, speak to your GP. Evopure makes the Magnesium Glycinate Sleep Complex and the Reishi Mushroom Adaptogenic Complex.
