Their study, published in the Proceedings for the 2003 Annual Meeting of the American Association for Cancer Research, clarifies a connection between lower intake of dietary folate and bladder cancer.
"The findings may have important implications for cancer prevention in susceptible populations," says Matthew Schabath, a predoctoral researcher working in the Department of Epidemiology.
He says that the ability to fix errant changes in DNA is of critical importance to maintain normal genetic structure, and this capability varies within the population. "A good prevention practice would be to limit exposure to DNA damaging agents (of which cigarette smoking is the most relevant for bladder cancer) and to eat foods containing folates and folic acid, such as fruits, vegetables, and fortified cereal grains, or take a daily supplement of folic acid, to reduce their risk of developing bladder cancer," he added.
Folic acid deficiency is one of the most common nutritional deficiencies in developed countries. Prior to the fortification of foods with folate, the deficiency was estimated to affect 10 percent of the U.S. population.
Folate itself is crucial to DNA synthesis and repair, Schabath says, so people who don't eat enough folate and who had inherited genetic instability are at much greater risk, he says.
Low intake of folate has already been associated with a number of cancers, including lung, cervical, colorectal, esophageal, brain, pancreatic and breast cancers, says Schabath.