The New Low-Cholesterol Diet: Walnuts

If you're like many Americans, you may crack open fresh walnuts only during the holiday season. But research shows there's good reason to enjoy this nut year round. Unless you're allergic to nuts, walnuts belong in a low-cholesterol diet. So get cracking.

How Do Walnuts Help?

"In general, nuts are good," says American Dietetic Association spokeswoman Suzanne Farrell, MS, RD. "But walnuts are great because they have high levels of omega-3 fatty acids. Other nuts don't."

Omega-3 fatty acids are also found in fatty fish like tuna and salmon. We know that omega-3 fatty acids lower levels of triglycerides, a type of fat in the bloodstream, although experts aren't exactly sure how. Omega-3 fatty acids may also slow down the growth of plaques in the arteries and reduce swelling throughout the body.

What's the Evidence?

There are a number of small studies that show that walnuts can help lower cholesterol.

One 2004 study of 58 adults with diabetes looked at the effects of eating a handful of walnuts each day in addition to a healthy diet. The researchers found that on average, people who ate the walnuts had an increase in their good HDL cholesterol and a drop of 10% in their bad LDL cholesterol levels. The results were published in the journal Diabetes Care.

An earlier Spanish study published in Annals of Internal Medicine in 2000 found that substituting walnuts for other sources of fat could lower total cholesterol levels by 4% in six weeks.

Because of the evidence, the FDA issued a "qualified health claim" for walnuts in 2004. This means that while the research is not conclusive, there is good evidence that walnuts can lower the risk of heart disease. Walnut growers are also allowed to advertise the health benefits of walnuts on their packaging.

Getting Walnuts Into Your Diet

Walnuts are easy to work into your meal plan. You can buy preshelled walnuts in any grocery store if you don't want to spend time cracking nuts. They don't need any preparation. Just eat a handful as a snack or add them to a trail mix. You don't need very many anyway.

You can also use nuts as a condiment. Sprinkle them on your salad, cereal, yogurt, fruit, vegetables, or entrees, suggest Keecha Harris, DrPh, RD and Ruth Frechman, RD, both spokeswomen for the ADA. Use nuts in pasta salads or in hot soups.

However, don't get seduced by anything less than a pure walnut. "When you're choosing nuts, make sure to get them raw and unsalted," Farrell tells WebMD. Candied walnuts give you extra calories that must of us don't need.

How Much Do You Need?

You can get the health benefits of walnuts from just a handful a day. About 1-and-1/2 ounces is plenty, experts say. Don't over do it.

"Although nuts have a lot of benefits, they're also high in calories that can add up fast," says Farrell. Gaining weight is likely to undo any of the heart-healthy effects of these foods.

The best way to add walnuts to your diet is to use them to replace less healthy fats -- like saturated fats in meats. That way you're gaining the benefits of walnuts without adding more calories.