CHAMPAIGN, Ill. -- The pastries, pizza, potato chips, french fries, margarine, cookies, crackers and bread that Americans consume by the millions of tons contain trans fat (hydrogenated oils). Most of these foods are made with flours deficient in vitamins B6 and B12 and magnesium. The combination of the fat along with the vitamin and mineral deficiency is partly responsible for the formation of calcified ridges that can block the flow of blood in arteries, scientists report.
So what should people do? Eat less trans fat and more foods rich in magnesium, B6 and B12, says Fred A. Kummerow, professor emeritus of food chemistry at the University of Illinois. But it's not that simple: "People can't easily lower their trans fatty acids intake, because they can't tell how much they are getting by looking at labels," Kummerow said. "Some products in Canada list percentages voluntarily, but U.S. food-makers do not, nor are they required to do so by the Food and Drug Administration."
Kummerow is the lead investigator of a study published in the November issue of the American Journal of Clinical Nutrition. Using cultured endothelial cells, his U. of I. team showed that calcification is related to the amount of trans fat, but that it can be mitigated with adequate magnesium levels. The researchers also tested other fatty acids, but did not find similar results.
"This paper shows us under what conditions trans fatty acids are a risk factor to the calcification of coronary arteries, which is the beginning of atherosclerosis, and if you translate this to the human diet, it means that adequate magnesium may modify the formation of calcified streaks," Kummerow said.
In addition to requiring food-makers to list the amount of trans fatty acid in their products, flour producers should be required to include B6 and B12 in their mixes, Kummerow said. Both vitamins prevent high homocysteine blood levels, another recently discovered risk factor in heart disease.
Flour already is fortified with thiamin, riboflavin, folic acid and niacin all B vitamins as well as iron, but it is incomplete without B6 and B12, he said. While at Clemson University in South Carolina in the early 1940s, Kummerow helped in the push to have niacin added to corn grits, a success that effectively stopped deaths attributed to pellagra in the South.
Despite years of debate, the evidence against trans fat is becoming clearer, Kummerow said. A May 1994 report in the journal Arteriosclerosis, Thrombosis and Vascular Biology noted that 99 percent of autopsied children between the ages of 2 and 15 had fatty streaks in their arteries. A study in the February 1999 issue of the Journal of the American Medical Association reported ridges of calcification in the abdominal aortas of all 2,800 people autopsied from ages 15 to 19.
Kummerow said that these results and his latest findings suggest that pregnant women should reduce their trans fatty acid intake and that a baby's first solid foods should be supplemented with magnesium. Adults should include foods containing B6 and B12 (chicken, fish, meat, eggs and dairy products) in their own diets.
Journal
American Journal of Clinical Nutrition