Making it Personal
Not everyone benefits equally from these "healthy" foods. Doctors know that megadoses of vitamins such as E and C can help ward off heart disease and cancer, but they don't know why some individuals respond more than others. Now DNA researchers are identifying the genetic types most likely to benefit from extra doses of specific nutrients. Just as blood tests can show an individual's vulnerability to disease, the researchers say they will some day be able to identify the exact daily doses we need, and determine which individuals will benefit most from certain vitamin supplements.
This capability is not as far off as it seems, says Jeffrey Blumberg, of Tufts University's School of Nutrition. "In the future, we'll be able to remove a white blood cell, look at your DNA and say, you as an individual need X requirements to delay the onset of diabetes."
In the year 2000, scientists will meet at a National Institutes of Health conference to discuss research that will someday help doctors administer a test to determine a patient's nutrition deficiencies -- much the same way that blood tests now identify anemic patients. Cyndi Thomson, a registered dietitian and a spokeswoman for the American Dietetic Association, says that such a test could help identify exactly which nutrients an individual needs to ward off disease. "Nobody wants to waste vitamins. What if you don't need vitamin X? What you might find is a certain nutrient that keeps the gene silent. We want to find out what is the amount that will prevent disease."
Research has already shown that perceptions of healthful recommended daily allowances have changed over the decades. In 1992, public health officials increased the folic acid recommendation from 180 micrograms to 400 micrograms when they discovered that this B vitamin could prevent birth defects.
But we'll never really have a magic pill or herbal cure-all, says Thomson. "No one really wants to take a pill." Her bottom line? "Eat your vegetables."