Trans Fat Raises Bad Cholesterol

April 19, 2004 -- Trans fats aren't listed on nutrition labels. But trans fats are in virtually all packaged foods -- and now there's evidence showing they cause can raise bad cholesterol levels.

There's already proof that trans fats cause heart disease but a new study involving pigs shows that two weeks on a high trans-fat diet can also significantly increase cholesterol, reports researcher Kyle K. Henderson, PhD, with the University of Missouri-Columbia. He is presenting his evidence at the Experimental Biology annual meeting held this week in Washington.

His evidence joins other studies showing that trans fat increases "bad" LDL cholesterol, possibly more than saturated fat. Trans fat also appears to reduce "good" HDL cholesterol, which saturated fat doesn't do. Trans fat also increases blood levels of two more artery cloggers -- triglycerides and lipoprotein(a). All of these elements work together to clog arteries and cause heart disease.

In this newest study, four adult pigs were placed on three different high-fat diets.

For two 14-day periods, the pigs consumed either a high trans-fat diet or a low trans-fat diet.

In the low trans-fat diet, coconut oil (a saturated fat) supplemented the pigs' usual diet. In the high trans-fat diet, hydrogenated soybean oil (a trans fat) supplemented the pigs' usual diet.

Pigs eating a high trans-fat diet had higher triglyceride and total cholesterol levels; they also had significantly lower HDL "good" cholesterol levels, reports Henderson.

With increasing information about trans fats, the FDA is now requiring manufacturers to label foods for trans fats by 2006.