Trans fats hinder multiple steps in blood flow regulation pathways

"Trans fats inhibited the synthesis of arachidonic acid from linoleic acid, even when there was plenty of linoleic acid available," he said.

The new study reports that in addition to interfering with the production of arachidonic acid from linoleic acid, trans fats also reduce the amount of prostacyclin needed to keep blood flowing. Thus blood clots may more easily develop, and sudden death is possible.

According to the American Heart Association, each year more than 330,000 people in the U.S. die from coronary heart disease before reaching a hospital or while in an emergency room. Most of those deaths are the result of sudden cardiac arrest, the Heart Association reports.

"This is the first time that trans fatty acids have been shown to interfere with yet another part of the blood-flow process," Kummerow said. This study adds another piece of evidence to a long list that points to trans fats as significant contributors to heart disease, he said.

Kummerow believes the U.S. Food and Drug Administration's new requirement (begun in 2006) that trans fats be included on food labels is inadequate and misleading. Anything less than one-half gram of trans fats per serving can be listed as zero grams, Kummerow said, so people are often getting the mistaken impression that their food is trans fat-free.

"Go to the grocery store and compare the labels on the margarines," he said. "Some of them say zero trans fat. That's not true. Anything with partially hydrogenated oils in it contains trans fat."

"Partially hydrogenated fats can be made trans fat-free," Kummerow said. "The industry would be helped by an FDA ban on trans fat that would save labeling costs, medical costs and lives."

Editor's note: To reach Fred Kummerow, call 217-333-1806 (a.m.) or 217-344-6380 (p.m.); e-mail: .