Nuts and seeds: A snack that's good for the heart

Eating nuts and seeds frequently can reduce the risk of heart disease, shows a major new study review.

Nuts lower cholesterol levels and are linked to a lower risk of cardio-vascular disease. By eating nuts, you reduce your risk of suffering or dying from a heart attack, shows a new systematic review and meta-analysis conducted by researchers working at the University of Oslo and the Karolinska Institute in Stockholm and elsewhere. They reached this conclusion after examining the results of 60 previous studies. Their review was part of the work being carried out on the development of new Nordic dietary guidelines.

"If you eat a handful of nuts every day, that is around 30 grams, you will have a 20 to 25 percent lower risk of suffering from cardiovascular disease. In comparison, adults in the Nordic countries only eat on average around 4 grams of nuts a day. Many do not eat nuts or seeds at all," says Erik Arnesen, research fellow at the University of Oslo and first author of the study.

A few nuts are better than nothing

Arnesen emphasizes that even though scientists say "the more the better," eating just a few nuts is better than none at all. Almonds, pistachios and walnuts appear to be the best for lowering cholesterol, but according to Arnesen there is so far no conclusive evidence for recommending specific kinds of nuts over and above others.

"Nuts have a beneficial effect on cholesterol levels in the blood, which it is important to keep low in order to prevent the build-up of fat in the arteries. This atherosclerosis, as it is called, is one of the greatest risk factors for heart attacks," he explains.

Uncertain whether nuts affect the risk of stroke and diabetes type 2

The researchers were also asked to investigate whether eating nuts reduces the risk of strokes and diabetes type 2 too.

"We are not sure about this. Nuts do not appear to affect blood pressure, which is one of the risk factors behind strokes. We cannot be sure whether nuts are good for blood sugar levels either, which are linked to the risk of diabetes type 2," says Arnesen.

The results of the systematic review and meta-analysis were recently published in the journal Food & Nutrition Research.

Eating nuts can improve cholesterol levels in the population

When it comes to cardiovascular health, the conclusion is that eating nuts is advantageous.

"Even though several studies have indicated as much previously, this is the biggest review so far on cardiovascular health," says Arnesen.

"Thanks to this systematic review and meta-analysis, we can present a more precise estimate of the actual effects. Proving that nuts lower cholesterol levels provides a credible explanation for why there is a connection between eating nuts and the risk of cardiovascular disease."

One of the reasons Arnesen gives for this connection is the composition of fatty acids in nuts.

"Even though nuts cannot be used to treat high cholesterol, we believe that the effect is significant enough to be used as a preventive measure amongst the general population," says the research fellow.

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