Johns Hopkins doctors explain the risks and benefits of consuming flaxseeds and other foods high in omega-3 fatty acids to improve your cholesterol profile.
Q. I take ground flaxseed to help control my cholesterol. But I read that the alpha-linoleic acid (ALA) in flaxseed increases the risk of prostate cancer. Is this true? Does the risk differ between ground flaxseed and concentrated flaxseed oil in capsules?
A. No real evidence has yet emerged to support the idea that ALA in flaxseed increases the risk of prostate cancer. According to a study in the Journal of Nutrition, however, "The association between high intake of ALA and prostate cancer is of concern and warrants further study."
ALA, an omega-3 fat similar to the fat in fish, is heart-healthy. Flaxseeds are one of only a few foods that provide ALA. Others are canola oil (from rapeseed), walnuts, and soybeans. Flaxseeds also contain compounds called lignans, which are thought to have anticancer effects. An article in The Journal of Urology reviewed 11 studies of ALA and prostate cancer. Some studies did suggest an association, but the researchers found the evidence unconvincing. They called for more research but emphasized that it was too early to make any recommendations.
Flaxseeds (in capsule or ground form), canola oil, soy, and walnuts can be part of a healthy diet—and their heart benefits are not in question. But don't go overboard: Very small amounts of these foods (one tablespoon of flaxseed or 1/2 oz. of walnuts daily) are enough to produce a beneficial effect. And for now, experts believe that flaxseed will not increase your risk of prostate cancer or worsen prostate cancer if you have it.
Q. How can I lower my triglycerides?
A. Like cholesterol, triglycerides are a type of naturally occurring lipid, or fat, present in the blood—and elevated levels of triglycerides increase your risk of heart disease. A desirable level of triglycerides is less than 150 milligrams per declilter (mg/dL), As numbers increase beyond that level, so does heart disease risk. Very high triglyceride levels—over 500 mg/dL— may predispose you to pancreatitis.
Treatment for high triglycerides is similar to general cholesterol treatment. Eating foods high in omega-3 fatty acids can help lower your triglyceride level. Fatty fish, like salmon, mackerel, and herring, are good sources, as are certain vegetable oils, nuts, and soy products. Also try cutting down on alcohol and sugary and starchy foods. Regular aerobic exercise and cutting calories help to lower triglyceride levels. If you smoke, quitting may improve both your triglyceride and total cholesterol levels.
If you can't get your triglycerides down on your own, your doctor may suggest fibrates, like gemfibrozil (Lopid) or fenofibrate (Lofibra, Tricor), which lower triglycerides while building up helpful HDL cholesterol. Or your doctor may prescribe a statin by itself or with a fibrate, although the risk of side effects rises with this combination. Niacin also lowers triglycerides, although it can affect glycemic control if you have diabetes.
