Nuts are everywhere – mixed nuts with pre-dinner drinks, pistachios in the turkey stuffing, chocolate-coated almonds under the Christmas tree and peanut butter on toast the morning after. Which ones are good for heart health? Do they encourage unwanted weight gain? And importantly for fans, is peanut butter an unhealthy spread?
Nuts are a rich source of healthy mono- and polyunsaturated fatty acids, along with protein, dietary fibre, essential micronutrients such as folate, calcium, magnesium, copper and potassium, and a range of phytochemicals. This makes nuts a nutritionally dense food; that is, one that contains lots of nutrients for its weight, as opposed to potato chips, which contain far fewer nutrients for the same weight.
Although the actual quantities of micronutrients in nuts may not be sizeable, research shows regularly including nuts in our diet increases overall diet quality and the amount of important nutrients we consume. Furthermore, clinical trials have found adding nuts to the diet for 3-12 weeks significantly reduces total cholesterol (TC) and so-called “bad” or LDL cholesterol levels. Nuts may also reduce inflammation and oxidative stress in our body cells, thereby contributing to a healthier cardiovascular system.
Whatever the reason, the evidence is that frequent nut consumption is good for our health and may help prevent cardiovascular disease, coronary heart disease, heart attacks and sudden death. Four large pooled US studies, for example, revealed people with the highest nut intake had a 34% lower risk of coronary heart disease (CHD).
Likewise, the European Prospective Investigation into Cancer and Nutrition study, involving nearly 400,000 participants, found people with the highest nut intake had a 29% lower risk of CHD mortality than those with the lowest intake.
Unsurprisingly, then, the National Heart Foundation’s new guidelines on nuts recommend regularly consuming a small handful (around 30g) of raw nuts to improve diet quality and reduce heart-disease risk factors. According to the research, each extra serving (30g) of nuts eaten a week is associated with an 8.3% reduction in risk of CHD-related death, irrespective of people’s diet and lifestyle.
Ideally, nuts should replace unhealthy foods such as highly processed items that have high levels of salt, sugar, saturated or trans fats, according to the Heart Foundation. For example, swap a bowl of potato chips for a handful of mixed nuts – different nuts have different amounts of micronutrients, so eating a varied selection is a great idea.
Tree nuts are the best options, specifically almonds, brazil nuts, cashews, hazelnuts, pecans, pine nuts, pistachios, macadamias and walnuts. And, interestingly, the often-maligned peanut is also a good option, according to the Heart Foundation, although technically peanuts are a legume. Chestnuts and coconuts don’t make the grade; their nutrient profile differs significantly from those of other tree nuts.
Nuts are best enjoyed raw with skins on, without added salt, sugar or other fats. If you like roasted nuts, the Heart Foundation recommends dry-roasting them in a shallow dish in the oven at a low to medium heat (around 100°C). Baking at a low temperature minimises acrylamide formation in the nuts. (See Nutrition, December 29, for more about acrylamide.)
Roasted nuts should be stored in a cool, dry, dark place to stop their good fats and nutrients deteriorating. There’s good news for peanut butter fans, too. Researchers say nut butters are equivalent to whole nuts in lowering cholesterol levels. Thus, one serving of plain nut butter (about two tablespoons) is a healthy alternative to whole nuts. Just choose a plain nut butter that’s low in added salt and sugar.
Still, given nuts are high in fat and energy, logic suggests they’ll contribute to unwanted weight gain. In fact, studies show nut eaters don’t gain more weight than anyone else. But err on the side of caution and use nuts to replace other less-healthy foods in your diet, rather than adding them to your typical diet. Which leaves only one thing to say – pass the nuts, please
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