Why this trans-fat is named phantom

Because consumers are unaware that hundreds of popular foods suchas crackers, biscuits, cookies, French-fries, shortenings, and many morecontain trans fatty acids:

"Prudent public policy would dictatethat their consumption be minimized and that information on the trans fattyacid content of foods be available to consumers." (American Journal of ClinicalNutrition. 66(4 Suppl):1006S-1010S, 1997)

Where do they come from?

Trans fatty acids (TFA) naturally occur in fat from animal meat (mostly beef,) dairy fat, and during the process of partial hardening liquid vegetable oils to produce margarine and vegetable shortening. This industrial technique, hydrogenation, is a process where natural essential fatty acids are destroyed and the new artificial ones appear.

Are TFA harmful?

There are serious indications that they are more harmful than theharmful enough natural saturated fats, especially to the heart. Departmentof Nutrition, Harvard, estimates conservatively that consumption of TFA areto be blamed for 30,000 premature deaths every year in the United States. How do they do their harm is not clearyet. For one thing, tissues of subjects with coronary disease contain nomore trans fatty acids than those of controls. (Prostaglandins Leukotrienes& Essential Fatty Acids. 57(4-5):399-402, 1997). However, TFA increasedthe ratio of total to HDL ("good") cholesterol nearly twofold compared withsaturated fats. (American Journal of Clinical Nutrition. 66(4 Suppl):1006S-1010S,1997).

One of the mechanisms of TFA adverse effects was suggested bythe Institute of Epidemiology, University of Münster, Germany. One of theTFA, linoelaidate 18:2(n-6)trans, inhibited growth of cells lining the bloodvessel walls thus interfering with its regeneration. (Journal of Nutrition.129(10):1791-8, 1999) bltfa1.htm

Epidemiological studies, includingbiomarker-based European studies, connected another health risk - prevalenceof childhood asthma and allergies associated with TFA intake (Report of theISAAC Steering Committee.)

How can we fight this newly discovered danger?

First, how bad is the danger?

Studies that have shown adverse effects of trans-unsaturated fatty acids on plasma lipoprotein levels have used levels of trans-fatty acid that are higher than those in the average U.S. diet. (Arteriosclerosis, Thrombosis & Vascular Biology. 17(9):1657-61, 1997). However, it is too early to sit back and take it easy. The adverse effects of TFA on good and bad cholesterol appear to be clinically measurable when the intake goes above 3% of energy intake bltfa6.htm and typical American intake varies from 3 to 17 grams TFA a day. (Journal of the American College of Nutrition. 15(4):325-39, 1996)

Can weight loss help?

In a way, yes.

Though weight loss did not induce any significant change of the different fatty acid families, it causes an increase in the concentration of essential fatty acid omega 3. (Annals of Nutrition & Metabolism. 36(5-6):336-42, 1992).

So, weight loss can help fight TFA making them less dangerous,because it was shown that essential fatty acids have a kind of neutralizingeffect on TFA:

"Although dietary trans fatty acids can effectthe fatty acid composition of tissues, they are not considered to be harmful,provided sufficient essential fatty acids are present in the diet." (Arzneimittel-Forschung.44(8):976-81, 1994)