How a serving of walnuts can lower cholesterol and boost brain power

Walnuts are often ignored in favour of ‘trendier’ nuts – but adding just a handful of them to your daily diet could reap serious benefits.

Nutritionally, these brain-shaped nuts punch well above their weight, especially when it comes to omega-3 fatty acids, a healthy fat that much of the UK is considered deficient in. 

These compounds are essential for our heart, brain and eye health – helping to lower blood pressure, prevent blood clots and manage depression and anxiety. 

‘When it comes to walnuts, a little goes a long way,’ says registered nutritionist Jen Walpole. 

‘They are rich in fat, fibre and protein which helps make them incredibly satisfying and satiating.’ 

And that’s not to mention the little kernels’ effect on cholesterol. 

Studies suggest that just one handful of walnuts a day is enough to lower total cholesterol – including the ‘bad’ LDL kind – by nearly seven per cent. 

With all these health benefits – and more – lurking inside just a few of these oddly-shaped nuts, we asked our expert the best ways to harness their plant power. 

What makes walnuts so healthy?

One 28g serving of walnuts contain roughly 180–200 calories, which is about seven to 10 per cent of the NHS’s daily calorie guideline (2,000 for women, 2,500 for men).

They are high in fat – around 18g per serving – making a significant contribution towards the 20g recommended for women and 30g for men.  

But while this might seem like a reason not to eat them, nutritionists say that most of this is actually unsaturated ‘healthy’ fat that much of the UK is considered deficient in. 

Called omega-3 fatty acids, these compounds are essential for our heart, brain and eye health – helping to lower blood pressure, prevent blood clots and manage depression and anxiety. 

And unlike other nuts, walnuts are particularly rich in one type of fatty acid – called alpha-linolenic acid (ALA) – which is more commonly associated with oily fish.

ALA is crucial for keeping cells in the body healthy – and has been shown to play a key role in managing blood sugar and treating nerve damage.

‘Omega-3 is an essential fatty acid, meaning we must obtain this through our diet, as we cannot make it ourselves,’ says Ms Walpole.

‘Omega 3 is extremely anti-inflammatory, supportive of cardiovascular function, brain function, hormonal health and fertility.’

And that’s not to mention walnuts’ effect on cholesterol. A growing body of research has found that walnuts can significantly lower ‘bad’ LDL cholesterol. 

Nutrients-wise, they’re rich in Vitamin E, magnesium and polyphenols, which act as antioxidants to reduce oxidative stress and inflammation. 

Polyphenols are often linked to reduced inflammation and lower long-term risk of conditions like heart disease.

What does the research say about the health benefits of walnuts? 

The omega-3 fats and polyphenols contained in walnuts have both been linked to brain health.

Some studies suggest the nuts may support cognitive function and be helpful in reducing age-related decline.

Their antioxidant content may also help protect brain cells from damage. As with many scientific studies, the evidence is promising but, so far, not definitive.

It’s heart health where walnuts really come into their own, however. 

A major study, published in medical journal Circulation found walnut consumption reduced total and LDL ‘bad’ cholesterol. 

Another large trial, the WAHA study (Walnuts and Healthy Aging), showed regular intake improved lipid profiles in older adults.

And an analysis in The American Journal of Clinical Nutrition confirmed consistent cholesterol-lowering effects across multiple trials.

Can eating walnuts help with weight loss or appetite control?

With a perfect combination of fibre, fat and protein, walnuts are great for snacking, say experts, especially when you’re implementing appetite control measures.

There’s around 2g of fibre per 28g serving of walnuts (the NHS recommends adults aim for 30g a day) and the nuts are low in both carbohydrates and sugar.

You’ll feel fuller for longer after eating them, which may help reduce cravings and overall calorie consumption. 

Keep a bag on your desk at work, or in your pocket when you’re on the move to stave off any hunger pangs, says Ms Walpole. Just be aware of overconsumption.

‘Omega-3 intake is linked to weight loss,’ says Ms Walpole. ‘This is because healthy fats are satiating, help with blood glucose control and impact cravings, too.’ 

Are there any side effects of eating too many walnuts?

Walnuts are a common allergen, so be cautious if you haven’t eaten them before – or at least not on a regular basis.

Overeating walnuts is a big no no. 

They can impact calorie count due to their high fat content. Of course, having too many will also influence weight management goals.

Some people may also experience digestive discomfort if consuming large amounts. 

Overall, says Ms Walpole, keep your consumption within the daily recommendation and you’ll get everything you need.

Likewise, it’s worth being aware of walnuts’ interaction with various medications.  

Those on blood-thinning drugs should seek advice from a medical practitioner before embarking on any kind of walnut-heavy diet regime. 

What should you pair them with for maximum nutrition?

Walnuts are a very easy upgrade to many meals, and they’re often used in baked recipes to add crunch – like banana bread, for instance. 

Crushed and sprinkled on salads, or mixed in with whole grains, will create a harmonious pairing, especially with leafy greens that are packed with Vitamin C.

Elsewhere, adding them to fibre-rich meals helps you move closer to your 30g daily fibre target, while chucking them in with key protein sources – lean meat, for instance – can improve satiety.

‘Walnuts are a great addition to any salad or vegetable dish (think toasted walnuts) and even work well as a snack alongside some berries as a fibre-rich snack or yoghurt for a protein focus,’ says Ms Walpole.

‘Walnuts also pair well with dark chocolate and may help to reduce sugar cravings or overeating chocolate. They would also be a great addition to a bowl of porridge oats for a well-balanced breakfast.

‘By adding walnuts and increasing the fat/protein content of this meal, it will help stabilise blood sugars and keep you fuller for longer.’