Essential fatty acids: not so essential after all

Most health-conscious folks have heard of essential fatty acids (EFAs) by now. It isn’t unusual for a health food store to sell several different brands of fish oils, flax oil and other blends of “essential fatty acids”. We’ve been told that consuming these oils will keep us healthy and protect us from disease.

Today’s nutrition textbooks refer to omega-6 (linoleic) acid and omega-3 (alpha-linolenic) acid as essential components of the human diet, and cite the requirement as something between one and four percent of total caloric intake. When scientists say a nutrient is “essential”, they mean it cannot be synthesized within our bodies from other components by any known mechanism - and therefore must be obtained from the diet.

But are “essential fatty acids” truly essential?

Chris Masterjohn, a PhD candidate in Nutritional Science at the University of Connecticut, has just published a paper which directly challenges the belief that omega-6 linoleic acid and omega-3 alpha-linolenic acid are essential.

His review of the scientific research suggests that omega-6 arachidonic acid (AA) and the omega-3 docosahexaenoic acid (DHA) are the only fatty acids that are truly essential - and thus necessary in the diet - for humans. Further, the true requirement for EFA during growth and development (during childhood, pregnancy or recovery from injury and illness) is less than one-half of one percent of calories when supplied by most animal fats, and even less (0.12 percent) when supplied by liver. In healthy adults, the requirement is “infinitesimal if it exists at all.”

So why is this a concern? Excess consumption of linoleate (omega-6 fatty acid) from vegetable oil will interfere with the production of DHA , while an excess of EPA from fish oil will interfere with the production and utilization of AA. So, by consuming an abundance of the oils which are today heavily promoted as “essential” - vegetable oil and fish oil - we are actually reducing the amount of the fatty acids that are truly essential - DHA & AA.

Finally, it must be pointed out that EFAs of all types, even the health promoting DHA & AA, are polyunsaturated fatty acids (PUFAs). PUFAs are widely known to contribute to oxidative stress, and oxidative stress directly contributes to many diseases including cancer and heart disease. This is why it is important to restrict our intake of EFAs to as close to the minimum requirement as possible.
Most people are far above this requirement, since vegetable oil is pervasive in the American diet. It’s in just about all processed foods (even the “healthy” ones), fried foods and everything cooked in a restaurant. And many people cook with it at home, without knowing what the dangers are.

The best sources of EFA in the diet are liver, egg yolk and butter from grass-fed animals. Obtaining these foods from pasture-raised animals is important, as they contain significantly higher concentrations of DHA and AA (the truly essential EFAs) and fat-soluble vitamins than their commercial feedlot counterparts.

Following these recommendations, along with a nutrient-dense, whole foods based diet low in sugar and rich in essential minerals, should reduce your intake of PUFA to closer to the recommended 0.5 (one-half of one) percent of calories, and ensure adequate intake of the truly essential DHA & AA.

Women who are pregnant or lactating, and perhaps attempting to become pregnant, children, and adults recovering from injury and suffering from chronic, degenerative disease can safely consume up to one percent of calories as PUFA. Studies have suggested that a subset of patients with pre-existing cardiovascular disease also benefit from a moderate dose of fish oil (up to one gram per day); however, in those same studies people with stable angina and with no heart disease at all, fish oil actually increased their risk of heart attack.

Check back here for a future post on what the research has to say about using omega-3 fatty acids (fish oil) in the treatment of heart disease.

Make sure to visit Chris Masterjohn’s website, where you can purchase the excellent full report for $15. It’s a worthwhile investment, in my opinion, if you want to get the straight scoop about EFAs and their role in our diet.