Peanuts may help to prevent heart attacks and strokes, controversial new research suggests.
Consuming three ounces of the nuts alongside a meal helped to suppress levels of a harmful type of blood fat, scientists found.
This in turn helped to ensure arteries stayed open, reducing the risk of heart disease - the world's leading killer.
But this portion size, which was blended into a liquid form, is about three times that of the average serving.
However, the study funded by The Peanut Institute, pointed out that the same effects may happen from eating the nuts whole.
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.
The same effects can be seen after eating a meal, with levels of triglycerides increasing, according to the Pennsylvania State University researchers.
Lead author Professor Penny Kris-Etherton 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 that if you eat peanuts with your meal, this can help prevent the stiffening response.
'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.'
To test the effects of peanuts, the researchers recruited a total of 15 overweight and obese men for the study.
One group were given a high fat meal accompanied by three ounces of ground unsalted peanuts in the form of a shake.
The others were given the same meal and a placebo drink, according to the study published in the Journal of Nutrition.
Blood samples were taken to test levels of blood fats and insulin while ultrasound recordings measured the flow through arteries.
The results showed a 32 per cent reduction in triglyceride blood levels after consuming peanuts.