Fruits may protect children from leukemia

U.S. investigators have found that children who ate oranges and bananas or drank orange juice most days of the week before age 2 were significantly less likely than other children to be diagnosed with leukemia before age 14.

Previous research has suggested that diet may influence the risk of certain cancers, including colorectal, prostate, lung and breast cancers.

Before age 15, more children become sick from leukemia than from any other type of cancer. However, the effect of diet on the childhood risk of this cancer remains largely unknown.

To investigate, Dr. Marilyn L. Kwan of the University of California, Berkeley, and her colleagues interviewed the mothers of 328 children diagnosed with leukemia and the same number of cancer-free kids. Mothers reported what children ate before age 2.

The leukemia cases and cancer-free children breastfed for a similar amount of time, and weighed roughly the same at birth.

The researchers found that children who age oranges or bananas 4 to 6 times per week were around half as likely to develop leukemia before age 14. Drinking orange juice between 4 and 6 times per week reduced leukemia risk by a comparable amount, the team reports in the American Journal of Epidemiology.

Kwan noted that cured meats such as lunch meats and hot dogs contain substances that can become carcinogenic in the stomach, and research in rats suggests that eating these meats in pregnancy may increase the risk of brain tumors in offspring.

However, in this report, eating hot dogs or lunch meats had no influence on leukemia, perhaps because vitamin C, along with other vitamins contained in fruit, protect the body from the damage the meats can cause, Kwan suggested.

"Perhaps in our study population of California children, child's early consumption of oranges and orange juice, foods which contain large amounts of vitamin C, hindered carcinogenesis," she told AMN Health.

Kwan added that more research is needed to investigate whether vitamin C protects against other types of cancer, and whether other foods, such as vegetables, can also protect kids from leukemia.

SOURCE: American Journal of Epidemiology, December 2004.