Eating vegetables and fruits containing carotenoids (carotene), the plant form of vitamin A, appears to decrease the chances of developing bladder cancer, a study by State University of New York at Buffalo researchers has found.
The study, compared the dietary histories of 351 men with confirmed bladder cancer with the diets of 855 men with no bladder cancer. It was conducted by a team of investigators from the University at Buffalo Department of Social and Preventive Medicine, headed by John Vena, Ph.D., associate professor.
Participants were selected from similar neighborhoods in Erie, Niagara, and Monroe counties in Western New York between 1979 and 1985. Dietary information was obtained via in-depth personal interview. Cancer patients reported their diets for the year prior to the onset of symptoms, while controls reported for the year prior to the interview.
Nutrients considered in the study were total vitamin A, vitamin A from animal sources (retinol), vitamin A from plant sources (carotene), vitamin C, vitamin E, vitamin D, crude and dietary fiber, calcium, thiamine, riboflavin, and niacin. Total caloric intake; calories from fat, carbohydrates and protein; dietary sodium; total daily fluid intake, and level of cigarette smoking also were analyzed.
In general, the study showed a positive link between bladder cancer and diet.
Researchers found a "strong dose-response relationship" between eating large amounts of fruits and vegetables containing carotene and lower risk.
Other findings include:
Higher consumption of protein appeared to lower risk.
High calorie intake was associated with an increased risk for bladder cancer in people under 65 years of age, with fat intake showing the strongest effect.
Higher intake of dietary sodium sodium derived from foods themselves, not added in cooking or at the table -- was associated with increased risk regardless of age.
Heavy smokers had three times the risk for bladder cancer as nonsmokers.
Participants with bladder cancer consumed significantly more coffee, soda, white bread, crackers, sugar, pre-sweetened cereals, macaroni, gravy, eggs, canned ham, liverwurst and cold cuts, smoked dried meat and smoked fish than participants without cancer. They ate significantly less celery, lettuce, carrots, green peppers, squash, peas, bananas and oranges than participants without the disease.