For about a decade, a growing number of studies have shown a relationship between consumption of dairy foods and/or calcium and the development of prostate cancer. Along the way, the role of magnesium also has been explored. While calcium is critical for healthy bones, there is also evidence that too much of a good thing may not be so good for men when it comes to prostate health.
In 2001, for example, the Harvard School of Public Health conducted a study in which the researchers followed 20,885 US physicians for 11 years. During that time, 1,012 men developed prostate cancer. When the investigators looked at how much calcium in the form of dairy products the men normally consumed, they found that those who averaged more than 600 mg calcium daily had a 32 percent higher risk of prostate cancer than those who regularly consumed 150 mg or less.
The American Cancer Society notes that there is evidence that high intake of calcium, mainly through supplements, has been linked with a greater risk of prostate cancer, especially aggressive cancer.
The results of this study show that, in older men, intake of dietary calcium of up to 1,300 mg daily in the form of dairy and other foods had no impact on the risk of prostate cancer—neither increasing nor decreasing the risk.
The men who got most of their calcium from food did, however, enjoy a 30 percent less risk of cancer of the esophagus, a 20 percent less risk of head and neck cancer, and a 16 percent less chance of colon cancer when compared with men who consumed low amounts of calcium.
In a study conducted several years earlier and by some of the same researchers, the impact of calcium and dairy foods on the risk of prostate cancer was evaluated in 293,888 men who were followed up for six years.
The researchers did not find an association between total and supplemental calcium intake and total and nonadvanced prostate cancer, but they did see a relationship between total calcium and advanced and fatal prostate cancer.
Skim milk, but no other dairy foods, was associated with an increased risk of advanced prostate cancer, while calcium from nondairy foods was associated with a lower risk of nonadvanced prostate cancer. (Park et al 2007)
More recently, it was reported in Cancer Research, a journal of the American Association for Cancer Research that amongst 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 and that calcium plays a risk in enhancing the role of prostate cancer development, according to lead researcher Lesley M. Butler, Ph.D., assistant professor of epidemiology at Colorado State University, Fort Collins, CO “. Dr. Butler added that “This study is the first to report an association between calcium and prostate cancer at such low levels and among primarily non-dairy foods.”
The report also noted that 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.
Magnesium and the Calcium/Magnesium Ratio
When experts talk about calcium, magnesium often is not far behind. That’s because this “other” mineral is critical not only for bone health but also has a role in about 300 biological functions in the body.
The ratio between calcium and magnesium appears to be crucial for prostate health, as several studies have shown. Specifically, when blood levels of magnesium are low and/or calcium levels are high compared with magnesium, the risk of prostate cancer is greater than when the calcium/magnesium ratio is at a healthy level.
Since it has been reported that 80 percent of adults have low magnesium levels, it seems logical to suspect that low magnesium may have a role in the increased risk of prostate cancer seen in men who have high calcium intake.
For example, in a sub-study of the Nashville Men’s Health Study, investigators at Vanderbilt University School of Medicine looked at the prostate biopsy results of 494 men: some with prostate cancer, some with suspicious lesions (a condition called prostatic intraepithelial neoplasia, or PIN), and some without cancer. They found that calcium levels alone had nearly no relationship with prostate cancer.
However, men with high-grade cancer had low magnesium levels along with high calcium levels. In addition, men who had low-grade cancer or PIN did not have an unbalanced calcium/magnesium ratio.
These findings led the authors to conclude that the most important factor in whether calcium contributes to a higher risk of prostate cancer is a man’s magnesium level, or his calcium/magnesium ratio.
Therefore, while high calcium intake may not be good for the prostate, it’s important to avoid a magnesium deficiency at the same time. This finding about magnesium may help explain why some studies have shown a relationship between calcium consumption and prostate cancer risk and others have not. The key may be magnesium.
See also
- Colostrum Increases Risk of Prostate Cancer
- Eggs may give you Prostate Cancer
- Calcium Increases Prostate Cancer Risk in African American Men
- Drinking Milk May Cause Prostate Cancer
- Calcium supplements
- 101 Ways to Love Your Prostate
- 46 Things to Avoid for Prostate Health
