‘Want a healthy heart? Make sure you get enough peanuts,’ ran the headline at Mail Online. The Daily Express added a bit more detail. ‘Eating THESE nuts could prevent stroke and even heart attack – but they must be unsalted.’ Unfortunately the study showed nothing of the sort. (Read our analysis below.)
The research, funded by the Peanut Institute, found that eating three ounces of nuts with a meal reduced levels of triglyceride, a fatty acid, in the blood.
During the study, published in the Journal of Nutrition, researchers examined a small group of 15 overweight and obese men. One group ate a meal that was high in fat with three ounces of ground unsalted peanuts. The others were given the same meal with no nuts.
Blood samples showed a 32 per cent reduction in blood levels of triglyceride among those who consumed the peanuts.
The study’s 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.’
Alarm bells start to ring when a study extolling the virtues of peanut consumption has been funded by the Peanut Institute, but somehow it gets worse as you read on. This study measures only postprandial triglycerides in a group of only 15 men. There is no long-term data. Additionally, the meal they are given is 1,198 calories’ worth of liquidised peanuts — not exactly a balanced or sustainable diet. There may well be benefits to eating peanuts, but many more extensive studies would need to be done to establish these in a reliable way.
Research score: 1/5