By Andrew Merle

Nuts are the most common snack among centenarians who live in Blue Zones — the places around the world where people live the longest — where they eat two handfuls of nuts per day.

Recently, studies have pointed to two types of nuts with especially potent health benefits. The first study, published in the journal Nutrients in August, analyzed data from 67,014 women and 26,326 men over a period of 20 years. The study found that eating walnuts was associated with a longer life expectancy. Specifically, a greater life expectancy at age 60 (1.30 years in women and 1.26 years in men) was observed among people who ate more than 5 servings a week of walnuts compared to those who did not eat any walnuts. A serving size was defined as 28 grams (1 ounce).

Eating walnuts was shown to reduce all-cause mortality, especially the risk of dying from cardiovascular disease. Consuming walnuts more than 5 times per week cut the risk of cardiovascular disease mortality by 25 percent, relative to non-consumers. This could be explained because walnuts contain a high amount of alpha-linolenic acid (ALA), compared to other nuts. ALA is a plant-based omega-3 fatty acid, which has been shown to improve blood lipids and endothelial function. Walnuts have also been proven to protect against obesity and oxidative stress.

Another study published in June in the journal Frontiers in Nutrition, points to the health benefits of almonds. Among 219 adolescents and young adults ages 16-25, eating 56 grams of almonds daily — roughly two handfuls, approximately 50 total almonds — significantly decreased blood sugar, total cholesterol, and LDL cholesterol over a period of 90 days. The benefits of almonds could be attributed to their high quantity of monounsaturated fat and antioxidant content. Other studies have shown beneficial health effects from eating just 20 grams of almonds.

When looking at the Blue Zone data and these two studies, it would be advised to consume two handfuls of nuts per day. While all nuts likely have health benefits, walnuts and almonds are two of the best.

More is not necessarily better. A 1-ounce serving of walnuts contains 185 calories and the same size serving of almonds has 170 calories. That means two servings add up to 355 calories, roughly 15% of a typical daily diet. For optimal health benefits, choose raw or dry-roasted nuts, without added sugar, salt, or oil.

Andrew Merle is a Certified Nutritionist who writes about living well. His website has been recognized as one of the best Habit Blogs on the internet, and his writing has been featured in media outlets such as TIME, New York Observer, Business Insider, HuffPost, Medium, Quartz, and Thrive Global. Read more of his articles at Subscribe to his email list at