High Calcium Intake Linked to Prostate Cancer

Moderation Is Recommended

Experts say excessive calcium intake may be unwise in light of recent studies showing that high amounts of the mineral may increase risk of prostate cancer.

"There is reasonable evidence to suggest that calcium may play an important role in the development of prostate cancer," says Carmen Rodriguez, MD, senior epidemiologist in the epidemiology and surveillance research department of the American Cancer Society (ACS) .

But evidence also shows calcium may lower the risk of colon cancer and age-related thinning of the bones, so moderation in intake makes more sense than avoiding the mineral completely, notes Rodriguez.

Studies Show Calcium-Prostate Cancer Link
Rodriguez says that a 1998 Harvard School of Public Health study of 47,781 men found those consuming between 1,500 and 1,999 mg of calcium per day had about double the risk of being diagnosed with metastatic (cancer that has spread to other parts of the body) prostate cancer as those getting 500 mg per day or less.

And those taking in 2,000 mg or more had over four times the risk of developing metastatic prostate cancer as those taking in less than 500 mg.

The recommended daily allowance (RDA) of calcium is 1,000 mg per day for men, and 1,500 mg for women.

Later in 1998, Harvard researchers published a study of dairy product intake among 526 men diagnosed with prostate cancer and 536 similar men not diagnosed with the disease. That study found a 50% increase in prostate cancer risk and a near doubling of risk of metastatic prostate cancer among men consuming high amounts of dairy products, likely due, say the researchers, to the high total amount of calcium in such a diet.

In 2000, a study involving some of the same authors focused on smokers in Finland. The study found that risk did not go up as calcium intake increased, and the authors called evidence of a calcium-prostate cancer link inconclusive.

The most recent Harvard study on the topic, published in October 2001, looked at dairy product intake among 20,885 men and found men consuming the most dairy products had about 32% higher risk of developing prostate cancer than those consuming the least.

Rodriguez says the evidence is not yet conclusive, but that the reason for the link between calcium and prostate cancer suggested by the researchers makes sense.

They note that the more calcium a person takes in through diet, the less the body produces of a kind of vitamin D — calcitriol — which has been shown to reduce replication of prostate cancer cells.

Calcium Benefits Important
Rodriguez says that while excess calcium intake may be linked to prostate cancer risk, it’s important to remember the mineral’s ability to help prevent osteoporosis (weakening of the bones usually associated with aging), and possibly to lower risk of colon cancer.

"Calcium appears to lower the risk of colon cancer, starting at about 700 mg of calcium per day, but taking more doesn’t give more protection," says Marji McCullough, a nutritional epidemiologist with ACS.

An 8-ounce glass of milk contains about 300 mg of calcium, an ounce of cheese has about 200 mg, and a serving of yogurt has about 312 mg, notes McCullough.

Moderation Is Best Strategy
Rodriguez and McCullough say that a middle ground between too little and too much calcium is the most sensible approach at this time.

"Moderate amounts of calcium may help reduce risk of colon cancer, but too much may increase risk of prostate cancer," notes Rodriguez. "Until more is known, men probably should avoid taking in more than the RDA of 1,000 mg of calcium per day."

"Moderation and balance are the keys here," concludes Rodriguez


Refference:This article took from http://www.cancer.org