Fat: Myths & Truths
Health Topics - ABC's of Nutrition
Friday, 31 December 1999 21:36
Myth: Heart disease in America is caused by consumption of cholesterol and saturated fat from animal products.
Truth: During the period of rapid increase in heart disease (1920-1960), American consumption of animal fats declined but consumption of hydrogenated and industrially processed vegetable fats increased dramatically. (USDA-HNI)
Myth: Saturated fat clogs arteries.
Truth: The fatty acids found in artery clogs are mostly unsaturated (74%) of which 41% are polyunsaturated. (Lancet 1994 344:1195)
Myth: Vegetarianism is healthy.
Truth: The annual all-cause death rate of vegetarian men is slightly more than that of non-vegetarian men (.93% vs .89%); the annual death rate of vegetarian women is significantly more than that of non-vegetarian women (.86% vs .54%) (Am J Clin Nutr 1982 36:873)
Myth: Vitamin B12 can be obtained from certain plant sources such as blue-green algae and soy products.
Truth: Vitamin B12 is not absorbed from plant sources. Modern soy products increase the body's need for B12. (Soybeans: Chemistry & Technology Vol 1 1972)
Myth: For good health, serum cholesterol should be less than 180 mg/dl.
Truth: The all-cause death rate is higher in individuals with cholesterol levels lower than 180 mg/dl. (Circulation 1992 86:3:1026-1029)
Myth: Animal fats cause cancer and heart disease.
Truth: Animal fats contain many nutrients that protect against cancer and heart disease; elevated rates of cancer and heart disease are associated with consumption of large amounts of vegetable oils. (Fed Proc July 1978 37:2215)
Myth: Children benefit from a low-fat diet.
Truth: Children on low-fat diets suffer from growth problems, failure to thrive & learning disabilities. (Food Chem News 10/3/94)
Myth: A low-fat diet will make you "feel better . . . and increase your joy of living."
Truth: Low-fat diets are associated with increased rates of depression, psychological problems, fatigue, violence and suicide. (Lancet 3/21/92 v339)
Myth: To avoid heart disease, we should use margarine instead of butter.
Truth: Margarine eaters have twice the rate of heart disease as butter eaters. (Nutrition Week 3/22/91 21:12)
Myth: Americans do not consume enough essential fatty acids.
Truth: Americans consume far too much of one kind of EFA (omega-6 EFAs found in most polyunsaturated vegetable oils) but not enough of another kind of EFA (omega-3 EFAs found in fish, fish oils, eggs from properly fed chickens, dark green vegetables and herbs, and oils from certain seeds such as flax and chia, nuts such as walnuts and in small amounts in all whole grains.) (Am J Clin Nutr 1991 54:438-63)
Myth: A vegetarian diet will protect you against atherosclerosis.
Truth: The International Atherosclerosis Project found that vegetarians had just as much atherosclerosis as meat eaters. (Lab Invest 1968 18:498)
Myth: Low-fat diets prevent breast cancer.
Truth: A recent study found that women on very low-fat diets (less than 20%) had the same rate of breast cancer as women who consumed large amounts of fat. (NEJM 2/8/96)
Myth: The "cave man diet" was low in fat.
Truth: Throughout the world, primitive peoples sought out and consumed fat from fish and shellfish, water fowl, sea mammals, land birds, insects, reptiles, rodents, bears, dogs, pigs, cattle, sheep, goats, game, eggs, nuts and milk products. (Abrams, Food & Evolution 1987)
Myth: Coconut oil causes heart disease.
Truth: When coconut oil was fed as 7% of energy to patients recovering from heart attacks, the patients had greater improvement compared to untreated controls, and no difference compared to patents treated with corn or safflower oils. Populations that consume coconut oil have low rates of heart disease. Coconut oil may also be one of the most useful oils to prevent heart disease because of its antiviral and antimicrobial characteristics. (JAMA 1967 202:1119-1123; Am J Clin Nutr 1981 34:1552)
Myth: Saturated fats inhibit production of anti-inflammatory prostaglandins.
Truth: Saturated fats actually improve the production of all prostaglandins by facilitating the conversion of essential fatty acids. (Price-Pottenger Nutrition Foundation Journal 20:3)
Myth: Arachidonic acid in foods like liver, butter and egg yolks causes production of "bad" inflammatory prostaglandins.
Truth: Series 2 prostaglandins that the body makes from arachidonic acid both encourage and inhibit inflammation under appropriate circumstances. Arachidonic acid is vital for the function of the brain and nervous system. (Price-Pottenger Nutrition Foundation Journal 20:3)
Myth: Beef causes colon cancer
Truth: Argentina, with higher beef consumption, has lower rates of colon cancer than the US. Mormons have lower rates of colon cancer than vegetarian Seventh Day Adventists (Cancer Res 35:3513 1975)
Written by : Jill Nienhiser