The skinny on fats & breast cancer

Townsend Letter for Doctors and Patients,  June, 2002  by Stephen Byrnes

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In today's nutritional world, fat has become a dirty word. Women in particular are encouraged to eat a low-fat diet to help prevent breast cancer, as well as other ailments, including other cancers. Animal fats such as butter have taken a terrible beating in the media over the past few decades and have been blamed for horrific crimes, including obesity, heart disease and cancer. Accordingly, Western peoples have been virtually brainwashed into thinking that butter and other predominantly saturated fats like coconut oil and tallow are unhealthy. So-called safe substitutes like margarine and various vegetable oils have been heavily promoted and advertised with the result being that the public associates these things with health and well-being.

Unfortunately for us, all of these contentions and claims are false. When it comes to breast cancer prevention, and in some cases treatment, the so-called "bad fats" are actually the good guys, and the "safe substitutes" are increasingly being shown up for what they really are: fabricated foods that cause disease, including breast cancer.

All Fats Are Not the Same

A common misconception the general public and some food writers hold is that all fats are essentially the same. This is not true. There are, to be sure, certain fats and oils that we need to avoid, but one must always be very specific as to what those are. Let's define our terms to end the confusion once and for all.

Fatty acids are chains of carbon and hydrogen atoms linked together in certain ways with an acid, or carboxyl group, attached to their end. When three fatty acids are bonded together with a glycerol molecule, the result is a triglyceride. In lipid biochemistry, all fatty acids are classified according to the number of carbon atoms present in their structure, as well as the degree of saturation, or how many hydrogen atoms are bonded to the carbons. A fatty acid that has two hydrogen atoms linked up to each carbon atom is saturated; a fatty acid with two hydrogens missing is monounsaturated; and a fatty acid with four or more hydrogens missing is polyunsaturated. All fats and oils, whether of animal or vegetable origin, are blends of these three types, but with one usually predominating, depending on the food in question.

Saturated fats predominate principally in animal fats, though palm and coconut oils are noted plant sources. Monounsaturated fats abound in nuts, avocadoes, olive oil, and some animal fats (especially lard). Polyunsaturated fats mostly make up vegetable oils, but significant amounts are found in fish oils and chicken skin.

It should be noted here that the more a fat is saturated, the more stable it is chemically. Saturated and mono-unsaturated fats do not go rancid easily if stored properly. Likewise, these fats are more stable under heat, making them ideal for cooking. Polyunsaturated fats, however, especially those of vegetable origin, are not as stable and go rancid more quickly, even in the body. Rancid oils breed one thing: cancer-causing and tissue damaging free radicals. While some polyunsaturated fats are needed by the body, the so-called essential fatty acids (EFAs), they should not exceed about 5% of your total caloric intake due to this problem. (1)

The two EFAs are linolenic (an omega 3 fatty acid) and linoleic (an omega 6 fatty acid). The "3" and "6" indicates where the first double bond occurs in the fatty acid molecule. For example, in an omega-3 fatty acid, the first double bond occurs at the third carbon atom. The body takes the EFAs and creates other omega-3 and 6 fatty acids and hormone-like substances called prostaglandins to carry out a host of metabolic functions. Like vitamins and minerals, EFAs must be derived from our food. In times past, humans consumed a balance of linolenic and other omega 3 fatty acids (found principally in cold water fish, walnuts, eggs, flax oil, dark green leafy vegetables, cod liver oil, and some whole grains) and linoleic and other omega 6 fatty acids (found principally in vegetables), and this is as it should be as both are equally important. When there is an overabundance of linoleic acid in the diet, however, our body's ability to absorb and utilize linolenic acid is inhibited. (2) This causes a host of undesir able reactions including sexual and immune dysfunction, and increased cancer risk. (3) The Western world has greatly increased its linoleic acid intake due to its higher use of vegetable oils over the past 60 years. (4) Not surprisingly, cancer (and heart disease) rates have skyrocketed.

There is another type of "fatty acid" that is produced during chemical processing called a trans-fatty acid (TFA). These are unnatural fats that our bodies cannot utilize properly due to their bizarre chemical structure. In a TFA, a liquid vegetable oil has been made solid by forcing hydrogen atoms into it with the help of a nickel catalyst. In terms of visual appearance, a hydrogenated fat looks like a saturated one since both are solid at room temperature. On a molecular level, however, the TFA is quite different, making it unusable by the body. These fake fats are found in margarine, "vegetable oil spreads," vegetable shortening, and refined canola oil. It is trans-fatty acid, as opposed to saturated fatty acid, consumption that is strongly correlated with cancer, cardiovascular disease, and other diseases. (5)