Why nuts are "natural health capsules"

In the biggest study of its kind, doctors and researchers at Harvard University monitored 210,000 people over three decades and discovered that those that ate nuts were 14 per cent less likely to suffer heart attacks, 20 per cent less likely to have heart disease and overall almost a quarter less likely to die from heart disease over the course of the study. The lead researchers described nuts as "nature's health capsules", with every 28g serving associated with a subsequent 13 per cent further reduction in heart disease.

"Tree nuts" such as Brazil nuts, cashews, hazelnuts and pistachios scored best on the health front - eating them frequently reduced participant's risk of clogged arteries by 23 per cent, with walnuts reducing risk by 19 per cent. The nuts eaten within the context of the study were raw and unprocessed - unfortunately nut butter hasn't yet been proven to have the same benefits, but it's certainly an exciting development given that heart disease is one the UK's biggest killers.

Luckily in the wake of this news, 26 per cent of us reach for nuts above any other type of food to tide us over until our next meal, according to research conducted by Sainsbury’s into our national snacking habits (and it's even got the royal seal of approval, with Meghan Markle  opting for almonds and almond butter when snacktime calls). Given that three quarters of women are regular snackers, compared to two thirds of men, chances are we’re squirreling away truckloads of nuts without even really noticing. Jasmine Hemsley  of  Hemsley+Hemsley  is one such ‘nutter’, but she notes that, while nuts are a healthy snacking option, as always in this life, it is sometimes possible to have too much of a good thing:

“When I was modelling I’d sit backstage and eat almonds because I was bored. They are really healthy, but nuts in general should be eaten in very small quantities and chewed well, otherwise they can cause an ache in the gut because they’re incredibly hard to digest.”

As with any food, overdoing it ain't advisable. For further intel on what nuts can do for you from a health P.O.V, we asked registered nutritionist  Rob Hobson  for his notes of nuts. Here’s his breakdown of the nut bowl, plus a few other nuggets of nutty wisdom.

We're hearing that nuts are little nuggets of health - how can we get the best out of them?

“When we are talking about nuts here we mean the raw variety and not a packet of KP dry roasted from over the bar in your local pub! There are a lot of nut-based snacks on the market that come in all sorts of flavours but you should try and avoid these salt-laden options. I eat nuts as a regular part of my diet, so buy lots of different types in bulk and decant them into separate containers ready to mix and match. My top tip here is that if you want to include them in your daily diet then keep the containers of nuts close to hand so that you don’t forget to add them to dishes, or just so there are the forefront of your mind when you’re feeling a bit peckish. I know this might sounds a bit basic but if they are in a cupboard it is easy to forget they are there. Before you know it years have gone by and your nuts are past their best.”

What are your favourite ways to eat nuts?

“Alone as a snack, crushed and used as a topping for breakfast yoghurt pots or sprinkled into salads and stir-frys. When I’ve got time I blend them with water to make nut milk- my personal favourite is cashew nut milk. I also love to add nuts to grain-based salad dishes- pistachios, walnuts, hazelnuts and cashews work particularly well.”

The health benefits of nuts

“Overall, all nuts are rich in monounsaturated fats that are commonly referred to as ‘good fats’. The nutritional profile of nuts differ between the varieties but in general they provide around 160 calories per serving and a source (more than 15% of the RDA) of vitamin E, magnesium  and selenium. Nuts also provide a little protein, although not all of the essential amino acids. Nuts contain some  iron , zinc,  calcium  and B vitamins including B1, B2, B3 and B6 .”

“In addition, nuts are a useful source of fibre . The fibre they contain is known as insoluble, which helps to bulk out stools and promote transit through the gut, which can help to prevent constipation.”

“Nuts also contain antioxidants called polyphenols. These help to reduce the damage caused by excess free radicals in the body that can damage cells and increase your risk of disease. We produce free radicals naturally as a byproduct of metabolism, and although free radicals have a positive role to play in the immune response, their production can increase in response to stress, pollution, excessive sunlight and smoking, and too many in the body can be damaging.”

“Nuts have been studied for their potential to reduce inflammation in the body too. Inflammation  is a very important mechanism that helps injuries to heal and protects the body from harmful pathogens (bacteria and viruses). However, under certain circumstances such as obesity, stress, poor diet, osteoarthritis or autoimmune diseases, the immune system may go into overdrive, often referred to as chronic low grade inflammation, whereby it sends an inflammatory response to a perceived threat that does not require one, and over time this may cause damage to organs and increase the risk of disease. Research suggests that eating nuts may reduce inflammation and promote healthy ageing. Varieties most researched include pistachios, Brazil nuts, walnuts and almonds.”

“Nuts have also been shown to be beneficial when it comes to lowering total and LDL (bad) cholesterol, while increasing HDL (good) cholesterol, which is likely to be an effect of the high monounsaturated fat content.”

Anything unhealthy about nuts?

“There is nothing inherently unhealthy about nuts, but just because they’re good for you doesn’t mean that you can gorge on them. Like all other foods rich in healthy fats, less is more. Three handfuls into the bag and you’re already looking at about 500 calories. Stick to the recommended serving size and eat them mindfully. You obviously get less of the larger nuts (like walnuts and Brazil nuts) per serving, so try breaking them up to make them last longer.”

What constitutes a serving of nuts?

“The recommended serving size for a portion of nuts is 30g. Don’t worry about counting or weighing out your nuts- just measure them so that you’re eating a small palmful. That’s normally a little larger than a golf ball, sizewise.

Nutritional benefits of different varieties of nuts (plus % of the RDA)

Brazil nuts

Selenium* (700%) *levels depend on where they have been harvested

Thiamin (vitamin B1)  (12%)

Magnesium (27%)

The breakdown:

Selenium supports immunity, helps with wound healing and is required to produce the active thyroid hormone. Brazil nuts are the richest food source of selenium. Just a few nuts is enough to meet you recommended daily intake.

Thiamin is required to convert food into energy and also supports a healthy nervous system.

Magnesium is essential to convert food into energy, helps to prevent tiredness and fatigue and supports normal muscle function.

Serving wise keep it simple- they work well as a snack.

Almonds

Vitamin E (37%)

Riboflavin (vitamin B2) (17%)

Magnesium (19%)

Calcium (10%)

The breakdown:

Vitamin E is a powerful antioxidant that helps to protect cells from the oxidative stress caused by excess free radicals- it’s required for healthy skin.

Riboflavin converts food into energy, supports a healthy nervous system, promotes healthy skin and is involved in the production of healthy red blood cells.

Calcium is essential for healthy bones, and almonds contain more calcium than any other variety. This makes them a useful addition to vegan diets  or anyone who is cutting dairy out of their diet. You can make a great nut milk with fresh almonds or add them to salads.  Calcium is especially important for women during the menopause who can lose up to 10% of their bone density.

Dietitian Lucy Jones  endorses Rob’s almond assessment:

“Almonds contain 15 essential nutrients (per 100g) which together support heart health, brain health, reduce feelings of tiredness and help to keep our metabolisms healthy. They are packed full of healthy fats and contain 6g of protein per serving. A daily portion reduces cholesterol levels, belly fat and helps you to feel fuller so you eat less at later meals.”

“In terms of cons, some people find price an issue, so make sure you check them out in the baking aisle instead of the snacking aisle in the shops and buy in bulk for better savings.”

“A portion is almonds comes in at around 28g, which equates to 23 almonds. That said, many health studies report even greater benefits when you eat more- up to 45g per day. A 28g portion provides 160 calories, although the most recent research shows that this is likely to be in the region of 20 per cent lower when we look at what we actually absorb when we eat them, making them a brilliant choice for people trying to manage their weight.”

Walnuts

Omega 3 (ALA)

Vitamin B6 (10%)

Magnesium (11%)

The breakdown:

Walnuts contain a good source of the omega 3 fatty acid alpha linolenic acid (AHA), which is converted to EPA and DHA in the body and has been shown to be beneficial to heart health.  For that reason, walnuts are a useful addition to the diet for people who don’t eat oily fish, for instance vegans and vegetarians .

Walnuts are also especially rich in ellagic acid which is an antioxidant that’s been linked to inhibiting the growth of cancer cells.

Vitamin B6 is required to convert food into energy, helps to maintain healthy blood glucose levels and supports a healthy nervous system. Research has shown that that vitamin B6 has a role to play in mood and depression associated with PMS.

In terms of drawbacks, according to NHS weight loss consultant surgeon Dr Sally Norton , the main factor is that walnuts have a slightly lower protein content, and more fat, that other types of nut. They can also occasionally have a bitter aftertaste.

Hazelnuts

Vitamin E (21%)

Thiamin (vitamin B1) (12%)

Iron (12%)

Magnesium (14%)

The breakdown:

Iron is required to produce healthy red blood cells, helps to ward off tiredness and fatigue and supports a healthy immune system. Hazelnuts contain the most iron of all the varieties of nut, which make them a handy addition to the diet of people with low levels of this mineral. Hazelnuts work well in puddings and make a great topping for yoghurt or grilled fruit.  Hazelnuts also work well with orange. This combo is delicious in salads, or you can crush hazelnuts and combine with orange peel to top salmon. Try this recipe  from my book and see what you think!

Dr Norton has some positive press to add where hazelnuts are concerned:

“Hazelnuts have one of the lowest percentages of saturated fat (along with pine nuts and almonds), plus the highest proanthocyanidins (PACs) content of all nuts. The antioxidant capabilities of PACs are likely to be 20 times more potent than vitamin C and 50 times more potent than vitamin E.”

Happy days.

Pistachios

Thiamin (vitamin B1) (16%)

Vitamin B6 (18%)

Phosphorus (15%)

The breakdown:

Phosphorus supports healthy bones and teeth.

Pistachios are also one of the only nut varieties to contain a source of lutein and zeaxanthin, both of which are essential for the health of your eyes.

Pistachios come shelled (often with added salt) or raw. Choose raw and try adding to grain salads- Moroccan flavours work especially well with this nut.

Just be aware of how many you’re putting away- while they’re low calorie as far as nuts go, they have the highest salt levels in the nut bag.

Cashews

Vitamin K (14%)

Thiamin (vitamin B1) (10%)

Iron (10%)

Zinc (12%)

Magnesium (20%)

The breakdown:

Cashews are the most magnesium rich of the nut family.  Magnesium  is involved in lots of chemical reactions in the body and is required to keep bones healthy, hearts beating steadily, muscles strong, nerve function sharp and immune systems hardy. Magnesium is often used by women to help to ease the  symptoms of PMS .

Cashew nuts provide more than 3g of iron per 50g serving, making them a brilliant snack for people with low stores of this mineral- low iron intake is a common problem for nearly a quarter of women in the UK and can lead to tiredness and fatigue.

Cashews, and most other nuts, are also a good source of copper which is utilised to help with the uptake of iron in the body.

Cashews make one of the most delicious nuts milks because they have a natural sweetness. Try adding cinnamon, raw cacao and a little honey for a healthy, rich chocolate milk.

The only con as far as Dr Norton is concerned is that, compared to some types of nut, they’re a bit low in protein.

Peanuts

Vitamin E (10%)

Niacin (vitamin B3) (19%)

Magnesium (12%)

The breakdown:

Niacin helps to keep skin healthy, is required to convert food into energy, supports a healthy nervous system and helps to ward off tiredness and fatigue .

Peanuts are a classic snacking option, but avoid salted or dry roasted varieties. Peanuts also work well in Asian style dishes such as Pad Thai.

Peanuts actually belong to the legume family and the proteins within them are responsible for one of the most common food allergies.

Pine nuts

Vitamin E (13%)

Vitamin K (19%)

Magnesium (18%)

Zinc (12%)

The breakdown:

Vitamin K helps to support healthy bones and is integral in efficient blood clotting.

Zinc is required for protein metabolism, supports immunity and also gives skin a boost.

Although not strictly a type of nut, they work well toasted and added to salads, and of course in pesto.

Pecans

Thiamin (vitamin B1) (12%)

Magnesium (8%)

The breakdown:

Pecans are one of the best types of nut to include in healthy sweet treats. They have a naturally sweet taste and enhance muffins, cookies and traybakes. Be aware that they’re the highest in fat of the nut varieties. Also don’t get your health kicks from the candied kind. Obvs.

Butter me up

Prefer your nuts smooth and spreadable? Dr Norton loves her nut butter as much as you do apparently:

“Nut butter is are a great on-the-go snack with a low glycaemic index to help you feel fuller for longer and suppress appetite. You can easily make your own, just by blitzing nuts (pre-roast for a few minutes if you like) in a food processor until the natural oils are released to form a buttery texture. If you go for shop-bought, check the label to find one that has no hidden sugar or palm oil.”

Obviously if you’ve been bathing in the stuff, you may be overdoing it- Dr Norton has some ideas and guidance for healthy nut butter consumption:

“Try adding a teaspoonful  to your morning smoothie for added protein, to help you feel fuller longer. You can also spread a teaspoonful thinly onto slices of apple or pear – the fibre in nut butter helps to slow down digestion and absorption of sugars from the fruit.”

“Wholegrain toast spread with a thin layer of peanut butter is also a favourite of mine- topping it with a sliced banana make for a great breakfast, or try it as a sandwich filling.”

Try these six seriously moreish nut butter recipes

Follow Rob on Twitter  @RHNutrition , Dr Sally Norton  @DrSally_Vavista,  Lucy Jones  @FoodWhispererRD  and Anna  @AnnaMaryHunter