Calcium, a mineral essential for building and maintaining bone, recently came under fire as a possible risk factor for prostate cancer in men. Several large studies indicated a possible connection between men who consumed large amounts of calcium developed prostate cancer more frequently than men who consumed a normal amount of calcium. Since calcium also has a number of health benefits, particularly in reducing the risk of osteoporosis for both men and women, talk with your doctor about balancing your calcium intake so that you receive the benefits without increasing the risks.
Calcium Dosage
The risk of osteoporosis, low bone density that increases your risk of fractures, particularly in the hip and spine, increases as you age. By age 65 to 70, men lose bone at the same rate as women, the National Institutes of Health reports. Calcium absorption also decreases as you age, so larger amounts may be prescribed to increase calcium levels. The Office of Dietary Supplements suggests that men over age 51 take in 1,000 mg of calcium per day, increasing to 1,200 mg per day over age 71. The ODS recommends a maximum daily intake of no more than 2,000 mg per day for men over age 51. Do not take more than 1,000 mg per day without first talking with your physician.
Prostate Cancer Frequency
For men, the risk of prostate cancer, the second most common cancer in men, also increases as they age. Prostate cancer rarely occurs before age 45. About one in six men will develop cancer in their lifetime, and one in 36 will die from the disease, according to the American Cancer Society. A 1998 Harvard School of Public Health study found that consuming 2,000 mg of calcium per day increased the risk of prostate cancer threefold, according to the Linus Pauling Institute at Oregon State University.
Studies
A follow-up study to the original Harvard School of Public Health 1998 study was reported in the October 2001 "American Journal of Clinical Nutrition." Lead author June Chan found that men who consumed more than 2.5 servings of dairy products per day, or 600 mg of calcium, increased their risk of prostate cancer by 32 percent over men who consumed 150 mg of calcium per day. An NIH study reported in the June 2007 issue of the "International Journal of Cancer" also reported an increase in prostate cancer in men with higher calcium intakes.
Theories
The Harvard study hypothesized that a high calcium intake lowers concentrations of the hormone 1,25-dihydroxyvitamin D-3, which is thought to protect against prostate cancer. This is the active form of vitamin D, also known as calcitriol. This theory has not yet been conclusively proven, the Linus Pauling Institute reports.
References
- American Cancer Society: High Calcium Intake Linked to Prostate Cancer
- Linus Pauling Institute: Calcium
- PubMed: Dairy Products, Calcium, and Prostate Cancer Risk in the Physicians' Health Study
- National Institutes of Health: Osteoporosis in Men
- National Cancer Institute: What are the Key Statistics About Prostate Cancer?
- PubMed: Dairy products, calcium, and prostate Cancer Risk in the Physicians' Health Study
