I enjoy nuts, and I’m happy to assure you that they have a firm place in a healthy diet. True, nuts are high in fat, but most contain monounsaturated fat that is good for the heart. The latest scientific word on the health benefits of nuts comes from researchers in the UK and Norway who analyzed 29 current studies on nut consumption and disease risk. They concluded that eating about 20 grams of nuts daily – about 0.71 ounces or the equivalent of a handful – is associated with a 30 percent reduction in the risk of coronary heart disease, a 15 percent lower risk of cancer and a 22 percent lower risk of premature death.
The researchers also reported that eating the same amount of nuts was linked to half the normal risk of dying from respiratory disease and a 40 percent reduced risk of diabetes.
The studies analyzed involved data on some 819,000 participants around the world and considered consumption of many kinds of tree nuts including walnuts, almonds, hazelnuts, Brazil nuts, cashews, pistachios, as well as peanuts, which are legumes and not nuts.
Because the studies reviewed were observational in nature, the analysis demonstrated only an association between nut consumption and reduced risk of disease, not cause and effect. However, the report’s co-author, Dagfinn Aune of the School of Public Health at Imperial College London, said that the researchers saw a “consistent reduction in risk across many different diseases, which is a strong indication that there is a real underlying relationship between nut consumption and different health outcomes.”
The researchers found no health benefits to eating more than 20 grams of nuts daily.
In addition to their healthy fat profile, nuts provide vitamin E, trace minerals, fiber, and in the case of walnuts, precursors of vital omega-3 fatty acids.
I eat nuts frequently, mostly raw and unsalted, and I store them in the refrigerator until I need them. If you like, you can toast nuts yourself by stirring them about in a dry skillet over medium heat. Or spread them on a baking sheet placed in a 350-degree oven; toss them occasionally until they are done. Use toasted nuts up quickly. Unsaturated nut oils oxidize quickly on exposure to heat, light and air, creating rancidity that makes them smell and taste bad (like oil paint). Rancid oils are pro-inflammatory and carcinogenic. Always smell nuts before you eat them or add them to recipes to be sure they are fresh.
Despite their beneficial nutritional profile, nuts are relatively high in calories as you noted, so enjoy them in moderation. I usually eat a handful per day – my favorites are walnuts, cashews, and almonds.
Andrew Weil, M.D.
Dagfinn Aune et al, “Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies”. BMC Medicine, December 5, 2016; DOI: 10.1186/s12916-016-0730-3