The Olive Oil Debate

Most researchers and health professionals now recognize that LDL or “bad cholesterol” plays the major role in promoting coronary artery disease (CAD) and also a major role for strokes. There is general agreement that saturated fat, cholesterol and trans-fatty acids should be reduced in the diet in order to lower LDL and reduce CAD. But what should replace those “bad” fats? This is where agreement stops and debate begins. Some researchers recommend a Mediterranean-style (MS) diet in which the “bad” fats are replaced with “good” fats, such as olive oil and canola oils. Others recommend a very low-fat, near-vegetarian (VLFNV) diet. Which approach works best may depend on the individual.For Patients Who Need To Lose WeightIndividuals who are overweight or obese, especially ones with Type 2 diabetes (NIDDM), need to lose weight to improve blood sugar regulation and lower their risk of heart disease. Research indicates that the most effective way to reduce body fat is to lower the calorie or energy density (ED) of the diet and increase exercise.A diet that is low in ED contains more fruits, vegetables, beans and whole grain products. Olive oil, and other monounsaturated fats, must be used very sparingly, because all fats and oils have a very high ED. Research has shown that adding oil to low-fat foods increases the amount of calories people must eat before they are full or satiated.The answer for people who want or need to lose weight is to replace “bad” fats with “good” carbohydrates rather than monounsaturated fat (MUFA). “Good” carbohydrates include: fruits, vegetables, brown rice, sweet potatoes, beans, winter squash, corn, whole grain pasta, oatmeal, whole wheat and other whole grains. They do not include: fat-free cookies and sweets, cereal bars, fat-free chips, pretzels, bagels, white bread, baked goods, crackers, frozen yogurt, soft drinks and candy.For Thin or Normal Weight DiabeticsIf a NIDDM patient does not lose weight, a high-CHO diet may have adverse effects on both blood sugar levels and blood lipids, which may increase the risk of CAD. In the case of the thin or normal weight diabetic, it may be worthwhile to focus more closely on low glycemic index foods. Nonfat dairy products and a moderate amount of fatty fish may help if triglycerides are elevated. The use of a modest amount of canola oil or olive oil, primarily in stir-fries and salad dressings, may also be tried if it results in a greater vegetable intake and does not result in weight gain.Thin, older, patients with Type 2 diabetes, who require insulin due to decreased insulin output, often do better clinically on a diet with more monounsaturated fat. Eating more nuts, seeds, avocados, soy products, fatty fish and more generous amounts of monounsaturated oils is usually better for this patient than eating a lot of refined, high-carbohydrate foods. The best case for a MS diet is for thin or normal weight patients with Type 2 diabetes.The Bottom LineA VLFNV diet may not always be best for treating the patients with more severe diabetes. However, its use earlier in the course of the disease will likely promote weight loss and reduce insulin resistance (IR). This should slow the progression of NIDDM and reduce the risk of CAD (assuming weight is lost and kept off). Better still, if a VLFNV is instituted earlier in life, it may prevent obesity and IR from developing, thus preventing or at least delaying the onset of Type 2 diabetes. A VLFNV diet will not only prevent atherosclerosis but has also been shown to reverse the disease process, and increase longevity in individuals with advanced CAD. This is something a diet high in MUFA has not been shown to do. A VLFNV diet with 2 servings of nonfat dairy products daily is similar to the DASH diet, which has been shown to help control blood pressure. Hypertension is common in overweight NIDDM patients, and greatly increases their risk for CAD, stroke, kidney failure and blindness.In America today, obesity and NIDDM are increasing rapidly. The trend toward fewer deaths from cardiovascular diseases (CVD) is now being threatened by the rapid rise of obesity and NIDDM, both of which greatly increase the risk of heart attacks and other circulatory problems. While nearly half of all American deaths can be traced to CVD, this rises to more than two-thirds of all deaths for people with NIDDM. ]Dr. James J. Kenney, PhD, RD, FACN is the Nutrition Research Specialist for the Pritikin Longevity Centers. He is on the Board of Directors for the National Council for Reliable Health Information and is Board Certified as a Specialist in Human Nutrition by the American Board of Nutrition.You may view Dr. James J. Kenney’s full text article with references at www.foodandhealth.com/oliveoil.htm or call us toll-free at 800-462-2352. It is the first of a series of articles on diet and heart disease and will be part of a 6-8 hour CPE program for dietitians on diet and heart disease coming next month. Next month we will look at the evidence of how a Mediterranean diet versus a low-fat near-vegetarian diet impact blood lipids and other risk factors for heart disease.