Smart eating had never been tested quite so literally. At the Society for Neuroscience's conference in San Diego last October, researchers presented several studies neatly demonstrating that a particular type of fat attacked brain tissue, muddying thought and destroying memory.

The audience was stunned. Most already knew that this particular fat gummed up arteries with a vengeance. But altering the brain? "After I did this study, my husband and I went through our fridge and threw out most of the stuff with trans fats in it," says neuroscientist Lotta Granholm, PhD, director of the Center on Aging at the Medical University of South Carolina.

Granholm studied rats, but most experts are grimly confident that the findings apply to humans. For 6 weeks, the rodents ate a diet mimicking the typical American's, except that one group's meals featured vegetable oil while the second group's contained trans fatty acids. This man-made fat is beloved by manufacturers for its solidity at room temperature (vegetable oil liquidizes) and its long, stable shelf life (saturated fat degrades).

To test the rats, Granholm and colleagues set up a series of progressively more difficult mazes. Rats eating trans fats made many more errors than the vegetable oil group; the more complex the challenge, the worse the trans fat eaters fared. And unlike the vegetable oil group, they didn't seem to learn from previous trips through a maze. Granholm suspects that the trans fats were choking off a key neurological protein, possibly by inflaming the brain's tissues.

A few months before Granholm presented her research, Lee S. Gross, MD, director of nutrition and diabetes education at Fawcett Memorial Hospital in Port Charlotte, FL, was creating a stir of his own after noticing an odd correlation between Americans' diets and their health. Food manufacturers had begun using a comparatively cheap new hybrid sweetener called high fructose corn syrup back in the late 1960s, and a few years later, rates of obesity and diabetes began to skyrocket.


The parallel was so striking that Gross began to collect more data, eventually publishing his results in the American Journal of Clinical Nutrition last May. "We kept seeing the same thing," says Gross. "As the consumption of corn syrup goes up, the number of diabetics goes up, too."

These two ingredients--trans fats and high fructose corn syrup--are in 40 percent of the foods Americans eat every day. And a growing number of experts believe that both are contributing to the epidemic levels of obesity, diabetes, and heart disease in the United States. How did they get into your food? And what can you do to keep them out of your diet? Read on for the latest news.

The "Perfect" Fat

Trans fats turn up naturally in milk and meat--in tiny amounts. But it's the man-made version that's causing all the trouble. When vegetable oil and hydrogen are put together under tremendous pressure, the resulting fat provides a taste and consistency that drives consumers wild. Read the entire article. "