This past week New York City became the first municipality to pass a ban on the use of trans fats in its restaurants. Restaurants around the city face serious consequences if they are found using oils that contains trans fatty acids (i.e., hydrogenated oils). Philosophical musings about free will and politics aside, this action will serve to make New York a healthier city.
What are trans fats and what impact do they have on health?
Trans fatty acids are often described as chemically-altered “damaged” fats, but that’s not exactly true, since they do occur in small amounts in beef and other ruminant meats. However, it is true that the majority of trans fats that are found in foods are a result of human intervention – the hydrogenation (or change in the bonds between hydrogen and carbon molecules) of unsaturated fats.
Hydrogenating unsaturated fat seems like a good idea on the surface. It allows for these fats to be used at higher temperatures, prolong shelf life and ward off rancidity, and allows them to stay solid at room temperature (since unsaturated fats tend to be liquid rather than solid form at room temperature). Both of these things are great if you buy into the lipid hypothesis, but in recent years the safety of trans fats have come into question.
Here is the problem, in simplified terms:
Your body utilizes fats in many of its functions – to create and maintain cell membranes, absorb and carry vitamins, insulate nerves, process and transport cholesterol, and compose hormones. When broken down, the individual fatty acids need to be ferried to the liver and various organs for these roles.
(You may want to get a partner for this next part)
“Normal”, natural unsaturated fats are all right-handed (from a chemical standpoint – they have what is called a cis molecular structure). The cell receptors that perform these tasks and carrier molecules that transport the fatty acids are all right-handed as well. The two meet, shake hands, and go about their merry way. Trans fats, however, are left-handed – their chemical structure is a trans formation. They meet the cell receptors and carrier molecules and attempt to shake hands.
(Try now to shake opposite hands with your partner)
Strange looks are exchanged and confusion passes over everyone. In the confusion, the carrier molecules say, “You chaps certainly are some strange fellows. I’m not quite sure what to do with you gents.” They then deposit these trans fatty acids somewhere “for safekeeping” until they can figure out what to do with them. Incidentally, that “somewhere” happens to be in your blood vessels.
Research has shown that consuming foods that contain trans fats increases the risk of coronary heart disease, diabetes, and obesity. It doesn’t help that trans fats are predominantly found in foods that are universally considered unhealthy for you anyway: processed snack foods, baked goods (Crisco anyone?), and deep-fried foods. It may also surprise you to find out (although I hope it doesn’t) that margarine, being a hydrogenated oil, is laden with trans fats.
Interestingly, trans fatty acids are unsaturated fats. With all the brouhaha over saturated fats, isn’t it funny how one of the major players in heart disease turned out to be a supposedly healthier alternative to saturated fats?
Let me stop myself before launching into a political tirade. Voluntarily reduce the amount of trans fats in your diet. You really shouldn’t be eating that Twinkie anyway.