Nuts are a superfood: they are rich in heart-healthy unsaturated fats and fiber, along with other vitamins and minerals and antioxidants.

In fact, nuts seem to do everything — from helping control blood sugar to reducing the risk of cancer and heart disease. Nuts can be expensive, but peanuts appear to be a good way to improve heart health and reduce mortality without breaking the bank.

Peanuts can provide a less expensive, but still effective, alternative to the pricier nuts.

Researchers looked at the diets of over 70,000 men and women from the southeastern U.S., and more than 134,000 people in Shanghai, China of lower socioeconomic status. They followed the participants for up to five and a half years, looking for connections between nut consumption and the risk of heart-related death and death from any cause.

People who ate the most nuts enjoyed about a 20% lower risk of dying from any cause. The American participants who ate the most nuts had a 21% reduced risk, while the Chinese participants had a 17% reduced risk of death.

Only peanuts were included in the Chinese phase of the study, suggesting that on their own peanuts are very heart-healthy.

Because they grow on bushes, peanuts are technically legumes, but they share most of the nutritional qualities of tree nuts — such as walnuts and almonds — and are usually considered nuts for health purposes.

Tree nuts tend to be expensive and out of many people’s price range as a snack. So the new study is an important addition, since it shows that peanuts can provide a less expensive, but still effective, alternative to the pricier nuts.

Nuts are high in total fat, so don't eat too many servings a day, otherwise you may gain a few extra pounds. And look out for nut butters with added sugars, since that can be another source of unwanted calories. If you can, eat natural nut butters, or better yet, grab a handful of nuts for a healthy snack.

The study was carried out by a team at Vanderbilt University’s School of Medicine and published in the journal JAMA Internal Medicine.