A high intake of calcium is linked to prostate cancer among African-American men who are genetically good absorbers of the mineral, U.S. researchers say.
Gary G. Schwartz at Wake Forest Baptist and colleagues at the Keck School of Medicine at the University of Southern California and the Cancer Prevention Institute of California studied 783 African-American men living in the San Francisco and Los Angeles areas.
More than 500 were diagnosed with prostate cancer. The researchers studied the effects of genotype, calcium intake and diet-gene interactions.
Although prostate cancer is 36 percent more common among African-Americans than in non-Hispanic whites, data on the diet-cancer link primarily comes from Caucasian populations.
The research team targeted a genetic allele that is more common in populations of African origin than in other populations and is associated with regulating calcium absorption.
The study, available online ahead of the January print issue of the Journal of Bone and Mineral Research, finds men who reported the highest intake of calcium were two times more likely to have localized and advanced prostate cancer than those who reported the lowest consumption.
Men with genes indicating poor calcium absorption were 59 percent less likely to have been diagnosed with advanced prostate cancer than men who genetically were the best absorbers of calcium.