Taking Your Diet to Heart
by Suzanne Girard Eberle, M.S., R.D.
What you can do today to decrease your risk of heart disease tomorrow.
When it comes to taking care of your heart, change is in the air. It's still valuable to know your blood cholesterol level and to check food labels for hidden fat, but the heart-healthy dietary prescriptive that has been traditionally dispensed has now changed considerably. The low-fat, low-cholesterol, high-carbohydrate approach is under challenge, while filling up on foods rich in certain nutrients — most notably folic acid and omega-3 fatty acids — is the current trend.
Focusing on the types of fat and carbohydrates you eat, not simply the quantity of each, has become as important as the age-old advice to limit cholesterol-laden foods, such as eggs and red meat. On top of that, flavonoids, vitamin-like substances found in plant foods, continue to promise impressive heart-protective benefits. Do your heart a favor and read on for the most current heart-smart dietary advice.
New Views On Fat and Carbohydrates
While not completely out of the doghouse, dietary fat is no longer seen as the sole villain driving up your risk of heart disease. Obviously, eating a low-fat diet can produce desirable benefits, such as lowering levels of total and low-density lipoprotein (LDL) cholesterol (a.k.a. the "bad" guy). Unfortunately, levels of heart-protective high-density lipoprotein (HDL) cholesterol (a.k.a. the "good" guy) may also plummet on a low-fat diet.
Furthermore, you may experience other unhealthy changes, such as an increase in triglycerides, while following a low-fat eating plan. Triglycerides, derived primarily from the fats you eat, or made by your body from excess calories coming from alcohol or carbohydrate-rich foods, increase the stickiness of your blood. High levels raise your risk of developing heart disease. One recent study of healthy men found that one-third exhibited a drop in HDL and a rise in triglycerides when switched from a 40 percent fat diet to a 20 or 25 percent fat diet (American Journal of Clinical Nutrition, 1999, vol. 69).
Before you toss that apple and order a double scoop of ice cream, though, keep this emerging information on dietary fats in perspective. The type of fat and carbohydrates you eat (a low-fat diet, after all, is by default high in carbohydrates) appears to be the most important factor in keeping your risk for heart disease low.
Saturated fat, the kind found in high-fat meats and whole-milk dairy products, remains the main dietary culprit in raising "bad" LDL cholesterol. Opting for three-ounce portions of lean poultry, fish and meat (the size of a deck of cards), non- or low-fat versions of dairy products and meatless meals several times a week still makes sense. So does limiting the amount of trans fats that you consume. Found in packaged foods made with hydrogenated oil, stick margarine and fried foods, trans fats deliver a double whammy — boosting levels of "bad" LDL cholesterol and lowering levels of "good" HDL cholesterol.
But the good news about dietary fat is that all fats aren't bad for you. Monounsaturated fat, the primary fat in olive oil, canola oil, nuts and avocados, doesn't increase LDLs and may actually raise beneficial HDLs. If you're struggling to keep your cholesterol profile in line on a low-fat diet, or you're just struggling through tasteless, low-fat meals, paying more attention to your intake of mono fats may be the solution.
The key, of course, is not to simply add mono-rich foods to your diet, but to substitute foods rich in monounsaturated fat for saturated and trans-rich foods that you eliminate. Chris Meletis, N.D., dean of clinical education and chief medical officer of the National College of Naturopathic Medicine in Portland, Ore., agrees: "As long as you maintain a healthy weight, adding some fat back to your diet in the form of monounsaturated fat is fine. Various ethnic diets readily demonstrate that."
Just as all dietary fats don't affect your cholesterol profile in the same way, neither do carbohydrates. Filling up on fat-free packaged foods or other foods similarly high in refined sugar and flour can contribute to elevated triglyceride levels. Consuming fiber-rich whole grains, on the other hand, can help reduce your risk for heart disease.
One convincing study followed more than 75,000 women with no history of diabetes or heart disease, and found that those women who consumed two to three servings of whole grains per day reduced their risk of heart disease by almost 30 percent (American Journal of Clinical Nutrition, 1999, vol. 69). Good choices include whole wheat bread and crackers; brown rice; bran flakes; whole grains such as buckwheat, bulgur and barley; toasted wheat germ; oatmeal; and popcorn.
Protection with Folate & Omega-3 Fatty Acids
The traditional means of fighting heart disease focused on eliminating foods from the diet. Today, loading up on certain foods appears to be the smartest move. Foods rich in omega-3 fatty acids, or the B-vitamin folate, pack the most protective punch. Without enough folate, for example, levels of the amino acid homocysteine increase in your blood, causing plaque to build up along blood vessel walls.
Studies consistently show that as homocysteine levels rise so does the risk of a heart attack (Annals of Internal Medicine, 1999, vol. 131). In fact, homocysteine may turn out to be a more reliable risk indicator for heart disease than cholesterol. To reduce your danger, fill up on folate-rich foods such as lentils, black-eyed peas and garbanzo beans; dark-green leafy greens; orange juice; and fortified breakfast cereals. You can also take a multivitamin containing the recommended daily folate dose of 400 micrograms.
Eating fish has long been touted as a great way to lower your risk of heart disease. The omega-3 fatty acid found in fish, eicosapentaenoic acid (EPA), deserves the credit. EPA can reduce your risk of blood clots and help prevent irregular heart rhythms. The best way to get omega-3s in your diet is to eat cold-water fish such as salmon or herring once or twice a week.
Meletis also recommends incorporating foods rich in alpha-linolenic acid, another heart-protective omega-3 fatty acid, into your daily diet. Canola and soybean oils, flaxseed oil, purslane (a leafy green) and walnuts also contain healthy amounts of alpha-linolenic acid.
The Power of Flavonoids
No heart-healthy diet is complete without flavonoids or phytochemicals, vitamin-like compounds naturally found in most deeply colored fresh fruits and vegetables, as well as green and black teas, red wine, herbs and soy products. Flavonoids help prevent damage to blood vessels by acting as powerful antioxidants. They also make blood cells less prone to clots, which can cause heart attacks. Aim for five to nine servings of fruits and vegetables per day.
The evidence for consuming soy flavonoids, also known as isoflavones, continues to grow. Whole soy products such as tempeh, tofu and green soybeans supply the most isoflavones. Aim for 25 grams of soy protein and at least 30 mg of isoflavones daily.
Suzanne Girard Eberle is a freelance writer based in Portland, Ore.