Vitamin A may reduce stomach cancer risk

NEW YORK (Reuters Health) - High intakes of vitamin A apparently reduce the risk of developing gastric cancer, Swedish researchers report.

Vitamin A comes pre-formed, as retinol in foods of animal origin, or in precursor form, as carotenoids in fruits and vegetables, Dr. Susanna C. Larsson, of the Karolinska Institute, Stockholm, and colleagues explain in the American Journal of Clinical Nutrition.

Vitamin A may influence the development of stomach cancer through its role in controlling cell proliferation, the researchers write. "However, epidemiologic studies of vitamin A, retinol (preformed vitamin A), and provitamin A carotenoids in relation to the risk of gastric cancer have documented inconsistent results."

The researchers examined the records of 82,000 Swedish adults who had completed a food-frequency questionnaire in 1997 and were followed through June 2005.

The average follow-up was 7 years. During that time, a total of 139 cases of gastric cancer were diagnosed.

A significantly lower likelihood of developing gastric cancer was seen with high intakes of dietary and total vitamin A and retinol, and of alpha-carotene and beta-carotene. Compared with the lowest intakes, the highest consumption of these compounds was associated with about a 50 percent reduction in the risk of gastric cancer.

Smoking affected how strongly vitamin A protected against stomach cancer, but alcohol drinking appeared to make no difference.

SOURCE: American Journal of Clinical Nutrition, February 2007.