Is this ingredient the secret to good brain health?

Masala Mackerel with Tamarind Chickpeas in Two Bowls

According to Holland and Barrett’s 2025 Wellness Trends report, many of us are thinking about brain food more than ever before. Omega-3 fatty acids are considered a key component for brain health because of the role they play in critical brain function. They’re known as an essential nutrient because your body can’t produce them on its own, so you need to get them through food.

There are three types of omega-3 fatty acids:

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), found mostly in fatty fish.
Alpha-linolenic acid (ALA), found primarily in plant-based sources.

The science: how omega-3 supports brain health

Our brains are actually made up of 60% fat, and a big chunk of the fatty acids found in brain cell membranes is DHA. This powerhouse fatty acid helps maintain membrane fluidity, allowing efficient communication between brain cells. This is crucial for neurotransmission, memory and general cognitive performance.

And it’s not just brain structure and function, studies have found that omega-3s:

Are anti-inflammatory, which may help reduce inflammation in the brain.
May lower the risk of neurodegenerative diseases like Alzheimer’s.
Maintain healthy blood flow to the brain.
Influence the production of our ‘happy hormones’, dopamine and serotonin.
Are critical in the brain development of infants and children.
Play a role in reducing age-related cognitive decline.
Reduce the risk of stroke.

And if that's not reason enough to incorporate more of it into your diet, registered nutritionist Michaella Mazzoni tells us there’s even more benefits. “Omega-3 offers many benefits. It supports cell health, which translates into supple-looking skin, and it’s also wonderful for supporting heart health as it can aid in keeping the balance right within the ‘good’ versus ‘bad’ cholesterol.”

Basically, omega-3s are a hard-working, essential nutrient, not only helping to keep our brains healthy but helping to keep other parts of our body in shape, too.

Foods high in omega-3

If you want to get the most brain-boosting benefits from omega-3s, your best bet is whole foods. Fatty, oily fish like salmon, sardines, and mackerel are rich in DHA and EPA. For plant-based options, flaxseeds, chia seeds and walnuts provide ALA.

However, it’s important to note here that your body needs to convert ALA into DHA and EPA, therefore it’s not as efficient or effective as getting your omega-3 sources from things like fish.

“Oily fish is always your best bet,” explains Mazzoni. “Salmon is great but can be pricey to eat all the time so tinned oily fish like anchovies or sardines which are milder in flavour are good, too.”

If you’re vegetarian, or don’t eat fish, regularly including plant-based ALA-rich sources may help. You can also look for fortified foods, for example omega-3 enriched eggs from hens that have been fed flaxseed, or enriched plant-based milks.

Best sources of omega-3s include:

Fatty fish: salmon, mackerel, sardines, herring, anchovies, trout
Shellfish: oysters, mussels, crab
Seeds and nuts: chia seeds, flaxseed, hemp seeds, walnuts
Oils: flaxseed oil, chia seed oil, hempseed oil, rapeseed oil
Algae-based sources: nori, wakame, kelp
Soy-based foods: edamame, tofu, soybeans

While there's not a definitive amount of omega-3s we should be consuming, the NHS recommends at least one 140g portion of oily fish a week. Girls and women who haven’t been through the menopause, including those trying to conceive, pregnant, or breastfeeding should have no more than two portions of oily fish a week. According to the Physicians Committee for Responsible Medicine, this is equivalent to around 1 tbsp of plant-rich omega-3 food a day.

Two plates of mackerel with crisp skin sat on a tomato and chickpea mix with a pink linen background

What about omega-3 supplements?

There are a lot of omega-3 supplements on the market, but it is always recommended to get your omega-3 intake through whole foods. According to The Association of UK Dietitians, omega-3 supplements are not recommended in the UK general population because evidence of benefits are inconclusive.

And you can have too much of a good thing, warns Mazzoni. “If you do take them, you should always follow the dose on your supplement,” she tells us. “And I recommend that if you are going to take a supplement don’t get cod liver oil and instead opt for omega-3 supplements sourced from small fish like anchovies.”

And what if you’re not getting enough omega-3s in your diet? “Things including skin irritation, dry skin, dry eyes, low mood and stiff or painful joints are all signs of omega-3 deficiency,” explains Mazzoni. “I test for omega-3 levels within my clinical work and having a deficiency happens more often than you think!” If you feel as though you may have an omega-3 deficiency, it’s a good idea to speak to a registered dietician, through a private clinic or via a GP referral.