Sunday, August 14, 2005

NY Times Defends Trans Fats

In what may be one of the dumbest articles on health I have ever read, a New York Times reporter defends trans fats, labeling a call by Dr. Thomas Frieden, the New York City health commissioner, to remove trans fats from restaurant foods the "panic du jour."

Author Gina Kolata suggests that the hype around the health risks of trans fats has been blown way out of proportion. She cites the valid fact that Americans consume much more saturated fat than trans fats as evidence that our concerns are misplaced. While it is true that saturated fats are the primary culprit in heart disease, it is also true that we need some saturated fat in our diets to maintain healthy hormone levels; around ten percent of fat calories consumed should be from saturated sources unless one is battling high cholesterol. Yet it is also true that we don't need ANY trans fats in our diets and that they serve no good purpose other than making processed foods more palatable. Trans fats could be completely removed from the American diet without any detriment to health and only a small financial loss for processed foods manufacturers.

What follows is an excerpt from an article I wrote on unhealthy fats for an issue of Equilibrium in the summer of 2003 that explains some of the science and dangers of trans fats.

First, the bad news: excess dietary fat has been linked to heart disease, obesity, autoimmune disorders, colon cancer, prostate cancer, breast cancer, and inflammatory diseases, such as arthritis. In terms of caloric intake, one gram of fat yields nine calories, while protein and carbohydrates each yield four calories. It has long been assumed that eating fat can make us fat -- in fact, eating the wrong fats can kill us.

Now, the good news: not all fats are equal. A handful of researchers, most notably the late Dr. Atkins, were able to prove that dietary fat is not the only factor that makes a person overweight. Their research and dietary strategies showed that carbohydrates -- and the associated rise in insulin levels -- are the most significant cause of body fat accumulation. These researchers also discovered that certain fats, such as the omega-3s, are good for us.

Saturated Fat
For years we have known that saturated fat increases serum cholesterol and is a leading cause of atherosclerosis (fat deposits in arteries). We know, therefore, that high-fat animal foods seriously increase the risk of heart disease and stroke. Unfortunately, this knowledge hasn't led to healthier dietary habits for the majority of Americans.

We also know that saturated fat is preferentially stored in adipose tissue (the body's fat cells), which explains why eating fat makes us fat. Because saturated fats have no double-bonded carbons in their structure, they can yield more energy per carbon than if they had double bonds (like the omega fatty acids), which is why the body stores them in adipose tissue.

The human body uses fats according to their structure. Polyunsaturated fats are used as the building materials for cell membranes due to their flexibility. Saturated fats are much more rigid, so the body will use them only as stored energy. Consuming saturated fats with a high carbohydrate meal (which significantly raises insulin) will result in the saturated fat quickly being shuttled into adipose tissue. A Big Mac, fries, and a chocolate shake is the perfect recipe for fat storage.

However, while the fat is still circulating in the blood, it has a tendency to clump due to its long-chain structure. These clumps of fat can be deposited within arteries, organs, and even muscle. When these clumps of fat are deposited in organs or around glands, they greatly increase the risk of cancer.

One possible explanation for the increase in cancer risk due to fat accumulation is the estrogenic properties of fat tissue. While estrogen is necessary for normal health, excess estrogen has been linked to breast and prostate cancers, and is suspected in several other forms of cancer, including colon and skin cancers. It turns out that adipose tissue not only has more estrogen receptors than normal cells, but it also can create estrogen. Therefore, the more adipose tissue a person carries, the higher the risk of developing certain types of cancer.

For many years, we thought saturated fat was the worst fat in the diet. But there has been a lot of research in recent years showing trans-fatty acids to be equally, if not more harmful.

Trans-Fatty Acids
Trans-fatty acids (TFAs) are created by the hydrogenation of mono- or polyunsaturated lipids. The process involves adding hydrogen to a vegetable oil in a complex chemical reaction involving high heat and pressure. The resultant oil is solid at room temperature and becomes rancid much more slowly. TFAs are used in most processed foods and are the foundation of margarine and vegetable shortenings.

Natural unsaturated oils are in a "cis" format, meaning that the hydrogen atoms are all on the same side. This allows the lipid to be more flexible, and most polyunsaturated fats are, in fact, curved, allowing them fit within cells without abnormally altering the cell's shape.

During the hydrogenation process, the hydrogen atoms move to the opposite side of the carbons, thus the designation "trans." This creates a fat molecule that is even more rigid than saturated fat -- a molecule produced naturally only in the stomachs of ruminate animals (and therefore found in small amounts in milk an animal fat). When TFA molecules, which resemble saturated fat more than unsaturated fat, are used in the formation of new cells and cellular membranes, they create more rigid -- and unhealthy -- cell structures.

Research has also shown that TFAs increase cholesterol at least as much as do saturated fats, possibly more. Although both types of fat seem to increase LDL cholesterol (the bad kind) equally, TFAs also reduce HDL cholesterol (the good kind). This factor alone makes them more harmful than saturated fats.

But trans fats are also implicated in increasing lipoprotein levels, which results in the formation of arterial plaque. The combined action of lowered HDL, increased LDL, increased cholesterol, and increased lipoproteins makes TFAs the single greatest dietary risk for coronary heart disease. In addition, TFAs contribute to the risk of type II diabetes and have been linked to the onset of several forms of cancer.

TFAs have absolutely no health benefits. All foods containing these products should carry a clear warning label, just like a pack of cigarettes. Personally, I believe that TFAs are as deadly as cigarettes. In fact, Holland has banned TFAs from food production, a step we unfortunately are not likely to see here.

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