While total calcium and vitamin D intake does not appear to impact the risk of prostate cancer, consuming your 3-a-day of dairy in the form of low fat or skim milk may actually increase the risk of malignancy, according to two studies recently published in the American Journal of Epidemiology …
Past research had indicated a potential link between dietary calcium and dairy product intake and prostate cancer, though the supporting evidence was not clear. In order to explore this topic further, these two large studies were launched.
The first was led by Dr. Song-Yi Park, from the University of Hawaii in Honolulu. His group conducted a Multiethnic Cohort Study of 82,483 men between the ages of 45 and 75, from 1993 to 2002. During that time, 4,404 of the men developed prostate cancer. No association was found between calcium and vitamin D and prostate cancer, regardless of if the source was via supplements or dietary intake. However, consumption of low fat and nonfat milk was related to an increased risk, while whole milk correlated with a decreased risk of total prostate cancer. The study does suggest that an association with milk consumption may vary by fat content, particularly for early forms of this cancer.
Another study, led by Dr. Yikyung Park, from the National Cancer Institute at the National Institutes of Health (NIH) in Bethesda, Maryland, produced similar results. Their research was conducted between 1995 and 2001, following 293,888 men.
Similar to the findings out of the University of Hawaii, skim milk was linked with advanced prostate cancer. In contrast, calcium intake from non-dairy foods was actually tied to a reduced risk of non-advanced prostate cancer.
If you aren't interested in increasing your fat and calorie intake, but have concerns of prostate cancer risk, then perhaps green tea would be the best beverage of choice. A third study published in December, found that men who drank five or more cups a day may cut their risk of developing advanced prostate cancer in half, when compared to those men who drank less than one cup a day.
Further studies will be required to solidify any of these possible connections.
American Journal of Epidemiology, December 1, 2008.
Reuters: Nonfat Milk Linked to Prostate Cancer