Eating nuts is absurdly good for you, recent research shows.
Big, high-quality studies are now showing consistent health effects from eating just 30 grams – a handful – of nuts a day.
Reduced risk of stroke. Reduced risk of cancer. Reduced risk of heart disease. Maybe even reduced ‘all-cause mortality’, which basically means your chances of dying from any disease.
The new research is likely to lead to nut consumption being promoted more heavily in the next edition of the Australian Dietary Guidelines, says nutritionist Rosemary Stanton, a member of the team that helped write those guidelines.
“There are more than 25 good studies relating to nuts, many recent, and some funded by nut growers. However, they all find benefits and I don’t know of any that don’t,” Dr Stanton says.
“We included nuts as a high protein choice and a good substitute for meat in the guidelines. Had the more recent studies been published when we did the dietary guidelines in 2013, we would have pushed them further.”
Among the most dramatic new work was a study published in the Journal of the American College of Cardiology last year – considered the world’s top heart-disease journal.
It pulled data from three studies, totalling 210,836 people, and found people who ate nuts five or more times a week had a significantly lower risk of coronary heart disease versus people who almost never ate nuts.
Peanut (I know, they’re legumes) and walnut intake was associated with a significantly lower risk of having a stroke.
Unfortunately for those who enjoy peanut butter on their morning toast, the delicious spread did not appear to have the same protective effect.
Add that to older studies which show cuts in cancer and all-cause mortality risk from eating nuts, and a picture of a remarkably healthy food is starting to emerge.
A randomised controlled trial, published in June, found a Mediterranean diet supplemented with nuts reduced heart disease risk even more than the same diet supplemented with healthy extra-virgin olive oil. A 2015 meta-analysis found 28 grams of nuts every day reduced all-cause mortality by 27 per cent.
Another team even estimated that a low consumption of nuts and seeds was the second-biggest cause of diet-related diabetes, stroke and heart-disease deaths in the USA.
“It’s consistent. If you look at all the research done over all the years, it’s telling a consistent story,” says nutrition scientist Dr Tim Crowe.
What makes nuts so healthy? We don’t know, says Dr Crowe, “but there are lots of theories”.
Nuts are full of healthy monounsaturated and polyunsaturated fats, which increase your good cholesterol and reduce your bad cholesterol. They are a good source of fibre, which is linked to good health outcomes.
And they are full of vitamins, minerals, and other valuable micronutrients we don’t fully understand yet.
When you choose to eat nuts, you choose not to eat something else – possibly something far less healthy. This ‘replacement effect’ is good for you as well. Importantly, nut intake does not seem to be associated with weight gain, despite nuts’ high calorie count.
But, cautions Dr Crowe, people after a healthy diet need to be wary of focusing too much on certain foods. The best diet is a balanced diet; there is good evidence eating more fruit and vegetables cuts your risk of heart disease and stroke.
“You can put a very strong case that legumes, fruits, and vegetables all have tremendous health benefits if you eat them regularly. Nuts are a worthy addition to the list, but there are lots of other healthy things you can be eating”
“Rather than focusing on any one superfood, it’s a combination of foods in our diet that are good for you.”