Peanuts BOOST heart health: Eating them 'could prevent heart attack or stroke'

The nuts help reduce the amount of clot causing lipids in the bloodstream by a third, according to the study.

Researchers say this leads to more supple arteries and stronger hearts – adding to evidence that nuts in general, including peanuts, help stave off a range of deadly illnesses.

Professor Penny Kris-Etherton, of Pennsylvania State University, said: “Typically, whenever we eat something, it causes the arteries to get a little bit stiffer during the post-meal period.

“But we have shown if you eat peanuts with your meal, this can help prevent the stiffening response.”

Previous studies have shown after a meal there is a spike in blood lipids or fats – such as cholesterol and triglycerides.

This can increase the risk of cardiovascular disease – which kills about 155,000 people in the UK each year.

In the study overweight and obese but otherwise healthy men ate about three ounces (85g) of unsalted peanuts in the form of a shake with a high-fat meal.

This would be about 84 nuts and contain almost 500 calories – before even starting to count what was in the other food.

But Professor Kris-Etherton and colleagues said the peanuts blunted the increase of lipids in their bloodstream – making their arteries more elastic and less likely to trigger a heart attack or stroke.

She said: “When the stiffening response happens in the cells that line the arteries, resulting in decreased elasticity in the arteries, it can limit the availability of nitric oxide, and when there’s less nitric oxide, the arteries don’t dilate that much.

“What you want is a dilation of the arteries and for them to be really elastic.”

She said over time stiffening of the arteries – also known as atherosclerosis – can limit blood flow throughout the body and cause the heart to work harder,

It occurs when fat, cholesterol and other substances build up in the walls of arteries and form hard structures called plaques.

These can then block the arteries and cause problems throughout the body – including cardiovascular disease.

Professor Kris-Etherton said: “As the heart works harder and harder, over a long period of time, it could lead, ultimately, to heart failure.”

The study, published in the Journal of Nutrition, showed eating peanuts can keep the cells that line the arteries healthy – helping them stay more elastic.

The researchers showed when peanuts are eaten with a meal the typical build-up of triglycerides – like cholesterol a type of fat found in the bloodstream – is dampened.

Professor Kris-Etherton said: “After a meal, triglycerides increase and this typically decreases the dilation of the arteries, but the peanuts prevent that big increase in triglycerides after the meal.

“And that may be the mechanism behind this effect, because the triglycerides are not getting so high, which may explain why there is not a decrease in artery elasticity.”

In the study 15 healthy overweight and obese men ate a meal with the shake containing three ounces of ground unsalted peanuts.

A control group was fed a shake of similar nutritional quantity and quality – but without the nuts.

The researchers took blood samples from the subjects to measure lipid, lipoprotein and insulin levels after 30, 60, 120 and 240 minutes.

An ultrasound machine was used to measure the subjects’ blood flow.

The researchers found there was a 32 per cent reduction in the triglyceride levels among those who had the peanut meal compared to the others.

Three ounces of peanuts is about three times the amount of an average serving size, they said.

But although the nuts were ground up into a shake for the study they said just eating peanuts would be expected to cause the same response.

Two years ago a study of more that 120,000 Dutch people found snacking on just half a handful of nuts (10g) a day can cut the risk of dying from diabetes and cancer as well as cardiovascular disease.

They also protected against respiratory disease, such as asthma and emphysema, and neurodegenerative diseases, which includes dementia.

People who ate peanuts showed similar reductions in mortality as those who ate tree nuts such as cashews, almonds, pecans and walnuts, among others.

But there was no protective effect from eating peanut butter – possibly because the salt and vegetable oils it contains cancel out the beneficial effects of the nuts.

Earlier results from American and Asian studies have also found tree nut and peanut consumption reduce cardiovascular diseases.

It’s believed the nuts contain various compounds such as monounsaturated and polyunsaturated fatty acids, various vitamins, fibre, antioxidants, and other compounds, that may contribute to the lower death rates.

Professor Kris-Etherton said future studies should have more participants and also include women.