Although scientists can now assess exposure levels to toxic agents and examine the body's response to those toxins through the presence of DNA variations known as biomarkers, finding the trigger point, or points, for disease onset is far more difficult. "Pure, genetically caused disease represents five to 10 percent of the disease burden in the United States; the rest is linked to a combination of multiple factors, both genetic and environmental," says Samuel Wilson, deputy department head, National Institute of Environmental Health Sciences (NIEHS). "Nutrition and lifestyle are huge factors, so we're trying to understand the linkages, including nutrition and lifestyle, in the context of molecular events occurring in cells that lead to the tissue changes characteristic of disease."
The environment-gene link is especially true with cancer. "The overwhelming evidence is that the environment is involved in the vast majority of cancers," says Neil Caporaso, a physician and chief of ...
