Sunday, July 24, 2011

The Nutrition Debate #21: The Dangers of Polyunsaturated Fats

For the last fifty years we have been told to eat less saturated fat and cholesterol and to exercise more, and we (collectively, as a population) have complied; yet, we (again, as a population) have been getting fatter and sicker. “The Nutrition Debate” is about why this has happened. If you’ve been following the column, you already know that I suggest an alternative approach is worth considering. If you haven’t read them, the previous columns are archived at

One of my favorite “alternative” organizations for nutritional information is The Weston A. Price Foundation. President Sally Fallon and Board Member Emeritus Mary Enig, PhD, collaborated in 2000 to produce a paper “The Skinny on Fats” as a chapter in their book “Nourishing Traditions.” If you have any interest in the subject of this mini-series, “Know Your Fats,” you will want to go to their site,, or just google “The Skinny on Fats” and read this article. Here, however, I will just reproduce an excerpt on “The Dangers of Polyunsaturates,” from a chapter in the book. The footnotes are all provided in the reference cited:

“The public has been fed a great deal of misinformation about the relative virtues of saturated fats versus polyun-saturated oils. Politically correct dietary gurus tell us that the polyunsaturated oils are good for us and that the saturated fats cause cancer and heart disease. The result is that fundamental changes have occurred in the Western diet.

At the turn of the century, most of the fatty acids in the diet were either saturated or monounsaturated, primarily from butter, lard, tallows, coconut oil and small amounts of olive oil. Today most of the fats in the diet are polyunsaturated from vegetable oils derived mostly from soy, as well as from corn, safflower and canola.

Modern diets can contain as much as 30% of calories as polyunsaturated oils, but scientific research indicates that this amount is far too high. The best evidence indicates that our intake of polyunsaturates should not be much greater than 4% of the caloric total, in approximate proportions of 2 % omega-3 linolenic acid and 2 % omega-6 linoleic acid. (30)

EFA [essential fatty acid, i.e. omega 3 and omega 6] consumption in this range is found in native populations in temperate and tropical regions whose intake of polyunsaturated oils comes from the small amounts found in legumes, grains, nuts, green vegetables, fish, olive oil and animal fats but not from commercial vegetable oils.

Excess consumption of polyunsaturated oils has been shown to contribute to a large number of disease conditions including increased cancer and heart disease; immune system dysfunction; damage to the liver, reproductive organs and lungs; digestive disorders; depressed learning ability; impaired growth; and weight gain. (31)

One reason the polyunsaturates cause so many health problems is that they tend to become oxidized or rancid when subjected to heat, oxygen and moisture as in cooking and processing. Rancid oils are characterized by free radicals-- that is, single atoms or clusters with an unpaired electron. These compounds are extremely reactive chemically.

They have been characterized as "marauders" in the body for they attack cell membranes and red blood cells and cause damage in DNA/RNA strands, thus triggering mutations in tissue, blood vessels and skin. Free radical damage to the skin causes wrinkles and premature aging; free radical damage to the tissues and organs sets the stage for tumors; free radical damage in the blood vessels initiates the buildup of plaque.

Is it any wonder that tests and studies have repeatedly shown a high correlation between cancer and heart disease with the consumption of polyunsaturates? (32) New evidence links exposure to free radicals with premature aging, with auto-immune diseases such as arthritis and with Parkinson's disease, Lou Gehrig's disease, Alzheimer's and cataracts. (33)”

When I first read this article, I went to the kitchen cabinets and (with permission) threw out virtually all the mostly polyunsaturated vegetable oils. I then went to The Weston A. Price Foundation website, bought the cookbook and started cooking only with saturated and monounsaturated fats.

The next column will get delve into detail on Omega 6’s and Omega 3’s, and how to correct this really important ratio.
© Dan Brown 5/22/11

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