PHILADELPHIA — Among Chinese men, calcium consumption — even at relatively low levels and from non-dairy food sources such as soy, grains and green vegetables — may increase prostate cancer risk, according to results published in Cancer Research, a journal of the American Association for Cancer Research.
"Our results support the notion that calcium plays a risk in enhancing the role of prostate cancer development," said lead researcher Lesley M. Butler, Ph.D., 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 non-dairy foods."
Some studies conducted in North American and European populations have linked high consumption of dairy products to an increased risk of prostate cancer. A few studies have suggested that calcium in milk is the causative factor, however the evidence is not clear.
What I wonder: Does the level of calcium needed to cause a prostate cancer risk rise with the amount of protein consumed? That might explain why a lower level of calcium consumption poses a risk in China which Western researchers only see at higher levels of calcium consumption.
This result is part of a larger body of evidence that too much calcium can boost prostate cancer risk.
Edward Giovannucci, M.D., Sc.D., professor of epidemiology and nutrition at Harvard School of Public Health, who is not associated with this study, said these results add more evidence that calcium is a causative factor of prostate cancer.
"However, there are some aspects that require further study," he said. "First, they found an association with relatively low intakes of calcium, whereas most previous studies suggested an association with high intake of calcium. Also, they found an association mostly in lean men, and whether this is true or is a chance finding requires further study."
An article in the the Journal of the American Society Nephrology (JASN) advises that too much calcium can cause calcium-alkali syndrome.
According to the authors, the obvious preventive strategy against the calcium-alkali syndrome is to limit the intake of calcium to no more than 1.2 to 1.5 grams per day. "Calcium supplements taken in the recommended amounts are not only safe but are quite beneficial. Taken to excess is the problem," said Dr. Goldfarb. "Even at the recommended dose, careful monitoring of any medication is wise and yearly determinations of blood calcium levels for those patients taking calcium supplements or vitamin D is a wise approach," he added.
Speaking as someone who takes vitamin D every day but calcium more sporadically so far the evidence for getting more vitamin D seems more compelling than the evidence for getting more calcium.
|Share |||Randall Parker, 2010 June 02 11:15 PM Aging Diet Cancer Studies|