Omega 3 and 6
Omega 3 & 6 – The good fat
Much has to be learned about the functions of linoleic acid (also known as omega 6) and linolenic acid (also known as omega 3) a term you may recall from the fish-oil craze a few years back). But scientists believe that these essential fatty acids govern growth, vitality and mental state. They are needed in the transport of oxygen from the red blood cells into other body cells, and form a structural part of all cell membranes. They are the precursors of prostaglandins, hormone like substances that help regulate many bodily functions, including blood pressure. And that’s only the beginning of the list: Put simply, the importance of essential fatty acids cannot be overestimated. The minimum daily requirement of essential fatty acids is modest, about I to 2 percent of total calories (or about a teaspoon for a person eating 1,800 calories a day). Udo Erasmus, in his book Fats and Oils (Alive Books, 1986), says the optimum daily amount is 9 to 30 grams, depending on various factors including physical activity, stress, nutritional state and individual differences. But his position is considered extreme. Why? Illness due to too few essential fatty acids is all but unheard of, it’s generally agreed.
Diets averaging 25 percent of their calories from fat have more than enough essential fatty acids to avoid deficiency symptoms, research shows. At this fat level, linoleic acid accounts for about 5 percent of the diet’s total calories,
more than twice the amount nutritionists believe is necessary for health. The upshot is that you probably don’t need to add more fats to your diet to get enough essential fatty acids. But if you want to be extra safe, choose the
fats you do eat from among the richest sources of linolenic and linoleic acids. The richest sources are the oils of flax, pumpkin, soybean and walnut. They contain both linoleic and linolenic acids. Other oils—such as safflower, sunflower, corn and sesame—are also good bets. Almost all foods, however, contain essential fatty acids. In vegetables, for example, 50 to 80 percent of the fat they contain is in the form of essential fatty acids, says James J.
Kenney, Ph.D., a nutritionist at the Pritikin Longevity Center in California.
Some evidence suggests that a high ratio of omega 6 (linoleic acid) to omega 3 (linolenic acid) may be detrimental to health. Cancer, for instance, may be linked to an imbalance of these essential fatty acids. Kenney says that a ratio of 4 to I is ideal, while a ratio of 10 to 1 may be unhealthful. That’s bad news for most Americans, who tend to eat omega 6 foods in much greater amounts than omega 3 foods. Now for the best—though yet to be Substantiated—news about essential fatty acids: At levels of about 12 to 15 percent of total calories, they may increase metabolic rate. In other words, they burn fat, Erasmus says, citing a study conducted in Germany. Sounds almost too good to be true, doesn’t it? Although provocative, this purported finding is by no means proven—and it’s not a license to start guzzling soybean oil as if it were water. Fat doesn’t have a bad reputation without reason. Of course, in earlier times, the plump among us were held up as models of health and wealth. But that’s not the case today—and justifiably so.