Calcium Consumption May Cause Prostate Cancer in Chinese

Among Chinese men, calcium consumption—even at relatively low levels and from nondairy food sources such as soy, grain, and green vegetables—may increase prostate cancer risk, according to results published in Cancer Research.

“Our results support the notion that calcium plays a risk in enhancing the role of prostate cancer development,” says lead researcher Lesley M. Butler, PhD, an assistant professor of epidemiology at Colorado State University, Fort Collins, Colo. “This study is the first to report an association at such low levels and among primarily nondairy foods.”

In an Asian diet, nondairy foods like tofu, grains, and vegetables such as broccoli, kale, and bok choy are the major contributors of calcium intake. Therefore, researchers speculated that people who are exposed to those calcium-rich food sources in an Asian diet may also be at increased risk for prostate cancer.

Using data from the Singapore Chinese Health Study, the researchers evaluated whether dietary calcium increased prostate cancer risk in a population of 27,293 Chinese men aged 45 to 74 years, with low dairy consumption. The study was restricted to men who belonged to two major dialect groups of Chinese people living in Singapore: the Hokkiens and the Cantonese.

Results showed a 25 percent increased risk of prostate cancer when comparing those who consumed, on average, 659 mg vs. 211 mg of total calcium a day, according to the study.

Major food sources of calcium in this population consisted of: vegetables (19.3%), dairy (17.3%), grain products (14.7%), soyfoods (11.8%), fruit (7.3%), and fish (6.2%). However, the researchers stress that there was no positive association with prostate cancer risk and any one particular food source.

Source: American Association for Cancer Research