Uncovering New Benefits to Calcium

When Dr. Emily White, associate dean of research at the University of Washington’s School of Public Health and Community Medicine, and her team at the Fred Hutchinson Cancer Research Center reviewed results from an ongoing study involving calcium’s effect on cancer last year, they stumbled upon a surprising new benefit to calcium — weight gain reduction.

The cohort study, published in the Journal of the American Dietetic Association in July 2006, showed that of 5,341 women in their 50s, those who took at least 500 milligrams of calcium supplements daily gained four pounds less over 10 years than women who did not use supplements.

Four pounds may not sound like a lot, but Dr. White assures four pounds is “pretty substantial.”

“These women were not on a diet,” she said. “They were not taking calcium to lose weight. We were not expecting to see this.”

In the last year, new findings have added to the list of calcium’s benefits. Studies published in 2006 showed calcium not only strengthens bones, lowers high blood pressure, and reduces the number of precancerous colon polyps, but also helps lower weight gain, and reduces the risk of hip fractures in senior citizens.

The Fred Hutchinson Cancer Research Center took a sub-sample from their Vitamins and Lifestyle study, led by Dr. White, and investigated 10,591 men and women from age 45 to 57 over an eight- to 12-year period in relation to calcium intake. The women who took more than 500 mgs of calcium, in supplements, gained 11.2 pounds over 10 years versus 15.2 pounds for those who did not get as much calcium. The researchers adjusted for energy intake and physical activity, as well as smoking and education, but the results stayed the same.

Men in the study did not seem to have the same benefits from calcium.

“A proposed mechanism for why calcium could lead to weight loss is it regulates fat metabolism in the cell,” said Dr. White.

Dr. White said a more definitive word on calcium’s role on weight gain reduction will come with the completion of a Women’s Health Initiative study in 2007. The study, coordinated by the Hutchinson Center which houses one WHI clinic, involves more than 36,000 postmenopausal women who took 1,000 mgs of calcium (and vitamin D) or a placebo daily for seven to 11 years.

A different WHI study in February 2006 showed that calcium continues to strengthen a woman’s joints long after peak bone mass is established (at age 18 for women and 20 for men). The study looked at 36,282 women between 50 and 79 years old over a seven-year period and found women over 60 who took 1,000mgs of calcium a day as instructed had a 29 percent reduction in hip fractures than those who did not.

“The fall in hip bone density was less in those who took the calcium and vitamin D supplements than those who did not,” explains Dr. Steven Ing, an associate of the lead author on the report and an Assistant Professor of Internal Medicine at Ohio State University. “Both groups were losing [bone density] at the end of the study, but those who were taking the vitamin D and calcium supplements had a lower risk of hip fractures.”

Everyone loses bone density as they age, however, if someone has achieved peak bone mass, or is getting adequate amounts of calcium, the rate will be lowered, said Patricia Vasconcellos, registered dietician and spokesperson for the American Dietetic Association.

Ninety-nine percent of one’s calcium is found in the 206 bones of one’s body. Bones are living organs with new parts being formed and broken down every day. If peak bone mass has not been reached and adequate calcium intake isn’t being met, the rate at which your bones break down greatly exceeds what they are putting back. Bones can then become stripped of calcium, leaving them brittle and easy to break—osteoporosis.

Getting enough calcium in adulthood is showing hope of reducing that brittle nature and possibly even reducing certain cancers.

While the WHI study on hip fractures failed to show a connection between reduced colon cancer and calcium, there are studies from 1999 that show both men and women who already had one intestinal precancerous polyp removed developed fewer polyps if they took calcium supplements.

“There is no definitive statement yet on colon cancer and calcium intake,” said Dr. White. “We feel there is some substantial evidence that calcium will show to reduce colorectal cancer though.”

Maximize Your Absorption

Only take 500 to 600mgs of calcium in one sitting, your body can not absorb more than that at one time. Also be careful what you are eating with your calcium source, it may be blocking your body from absorbing the calcium.

“Do not take calcium and iron supplements at the same time,” warned Stephanie Spaide, RD and Director of Outpatient Nutrition Services at Boston Medical Center’s Center for Nutrition and Weight Management. “Iron makes calcium less available for absorption.”

Also eating foods high in phytic and oxalic acids, like bran cereal, spinach, collard greens, beans, sweet potatoes and rhubarb, will stop your body from absorbing most of the calcium you take in; because the acids bind to the calcium and form an insoluble salt.

Be sure to take Vitamin D supplements or get 30 minutes of direct sunshine daily in order to better absorb calcium.

Read Labels

“There is a lot of false advertisement out there,” warns Dr. Ing. “Read the fine print.”

A supplement bottle may claim to have 1000mgs of calcium in it, but if you read the fine print, the calcium may be calcium carbonate, a crystallized version of calcium. That means there is actually only 400mgs of elemental calcium in the supplement. And some supplements consider two or even three pills a serving size.

Some supplements do not dissolve properly either. To test if your supplement is dissolving properly, take a half a cup of water and put one teaspoon of vinegar in it. Drop the supplement in and stir it around. Wait half an hour to an hour, if the acidity in the vinegar water does not dissolve the pill, your stomach might not either, said Gregory Miller, executive vice president of research at the National Dairy Council.