Eating nuts helps your heart. Learn from a Mayo Clinic specialist how walnuts, almonds and other nuts help lower your cholesterol when eaten as part of a balanced diet.
Gerald T. Gau, M.D.
It sounds a little — pardon the pun — nutty, but there's growing recognition that eating nuts as part of a healthy diet is good for your heart. Nuts, which contain unsaturated fatty acids and other nutrients, are a great snack food, too. They're cheap and easy to store.
The type of nut you eat isn't that important. Walnuts, almonds, hazelnuts, you name it, almost every type of nut has a lot of nutrition packed into a tiny package. If you have heart disease, eating nuts instead of a less healthy snack can help you more easily follow a heart-healthy diet.
Dr. Gerald Gau is a Mayo Clinic preventive cardiologist and is a specialist in internal medicine and cardiovascular diseases. He's been involved with the National Cholesterol Education Program Coordinating Committee, which develops national cholesterol guidelines. He shares his insights on the heart-health benefits of eating nuts.
Can eating nuts help your heart?
It sure looks that way. Most studies on people who eat nuts as part of a heart-healthy diet have found that nuts lower the LDL, low-density lipoprotein or "bad," cholesterol level in the blood. High LDL is one of the primary causes of heart disease, so nuts' ability to lower LDL cholesterol seems to be quite beneficial.
Eating nuts reduces your risk of developing blood clots that can cause a fatal heart attack. Nuts also improve the health of the lining of your arteries. The evidence for the heart-health benefits of nuts isn't rock-solid yet — the Food and Drug Administration only allows food companies to say evidence "suggests but does not prove" that eating nuts reduces heart disease risk. Still, the existing evidence looks promising.
What's in nuts that's thought to be heart healthy?
It's not entirely clear, but it's thought that the unsaturated fats in nuts — both monounsaturated and polyunsaturated fats — lower bad cholesterol levels. Many nuts are also rich in omega-3 fatty acids. Omega-3s are a healthy form of fatty acids that seem to help your heart by, among other things, preventing dangerous heart rhythms that can lead to heart attacks. Omega-3 fatty acids are also found in fish, but nuts are one of the best plant-based sources of omega-3 fatty acids. Nuts also have lots of arginine, which is a molecule that increases the production of nitric oxide in your body, which may in turn help improve the health of your artery walls and make them more flexible and less prone to blood clots. Other substances in nuts that could improve your heart health include Vitamin E and fiber.
Does it matter what kind of nuts you eat?
Possibly. Most nuts appear to be generally healthy, though some more so than others. Walnuts are one of the best-studied nuts, and it's been shown they contain high amounts of omega-3 fatty acids. Almonds, macadamia nuts, hazelnuts and pecans are other nuts that appear to be quite heart healthy. Even peanuts — which are technically not a nut, but a legume — seem to be relatively healthy. Keep in mind, you could end up canceling out the heart-healthy benefits of nuts if they're covered with chocolate, sugar or salt.
What amount of nuts is considered healthy?
Nuts contain a lot of fat; as much as 80 percent of a nut is fat. Even though most of this fat is healthy fat, it's still a lot of calories. That's why you should eat nuts in moderation. Ideally, you should use nuts as a substitute for saturated fat. Instead of eating unhealthy saturated fats, try substituting a handful of nuts. Current dietary guidelines suggest eating 1 to 2 ounces (a small handful) of nuts each day. But again, do this as part of a heart-healthy diet. Just eating nuts and not cutting back on saturated fats found in many dairy and meat products won't do your heart any good.
Are there other benefits of eating nuts?
Probably. Nuts contain Vitamin E, which, in addition to possibly being good for your heart, is thought by some researchers to help protect your cells against some forms of cancer. However, the evidence for Vitamin E's benefits in heart disease or cancer prevention is rather slim at the moment. Another theory is that Vitamin E might help prevent cataracts. Nuts also contain fiber, and a high-fiber diet is thought to help prevent heart disease and diabetes. A diet high in foods that contain fiber also might help prevent colon cancer, but the evidence here is mixed.
How about nut oils? Are they healthy, too?
Nut oils are good sources of omega-3 fatty acids and vitamin E. Walnut oil is highest in omega-3s. Nut oils contain saturated as well as unsaturated fats. Consider using nut oils in homemade salad dressing or in cooking. When cooking with nut oils, remember that they respond differently to heat than do vegetable oils. Nut oil, if overheated, can become bitter. Just like with nuts, use nut oil in moderation to restrict overall calorie and fat intake.
http://www.mayoclinic.com/health/nuts/HB00085