Bone scans reveal that millions of middle-aged and older Americans – mostly women – are developing osteoporosis, the loss of bone density that can lead to frequent, painful fractures. The cause is often a lack of calcium in the diet. But new studies show that calcium is crucial not just for our bones.
Researchers now believe that a lack of calcium in our diets plays a critical role in health problems for women and men that range from high blood pressure to colon cancer to premenstrual syndrome.
The protective effects of calcium against formation of cancer cells in the colon have been shown in numerous animal studies. It is thought that bile acids and fatty acids stimulate cell reproduction and irritate or damage the epithelial cells of the colon. Calcium binds these substances into insoluble complexes, reducing their ability to do damage.
Researchers at three New York medical centers followed 70 people with a history of benign colorectal polyps over the course of one year. Of this group, 37 patients increased their daily calcium intake to 1200 while the remaining 33 patients were asked to maintain their usual diet.
At the beginning of the study, the two groups showed no significant differences in the proliferation of cells lining the colon. The proliferation, or growth, of cells is used as an indicator of “the effects of chemopreventive agents in human studies of colon cancer prevention,” note the research team, led by Dr. Peter Holt of St. Luke’s/Roosevelt Hospital Center in New York, New York.
At 6 and 12 months the experimental group who increased their calcium intake showed a decreased number of proliferating cells in the epithelial cells lining their colons, but there was no change in the control group.
A 1998 study of 497 women, conducted at St. Lukes-Roosevelt Hospital Center in New York City and published in the American Journal of Obstetrics and Gynecology, concluded that daily doses of calcium can reduce by at least half the physical and psychological symptoms of PMS. Women taking 1,200 milligrams of calcium daily reduced the incidence and severity of generalized aches and pains by 54%, psychological symptoms by 45%, food cravings by 54% and water retention by 36%.
“It is essential for every organ, every tissue, every system. If you don’t have calcium, nothing functions,” says Susan Thys-Jacobs, a researcher who studies the role of calcium at Saint Luke’s-Roosevelt Hospital in New York City.
Ms. Thys-Jacobs says people of all ages need to consume the amount of calcium in four glasses of milk a day. But guess what? Nobody is drinking four glasses of milk a day, says Thys-Jacobs.
While we need from 1,000 to 1,500 milligrams of calcium every day, most of us consume about 450. As a result our bodies produce excess hormones – vitamin D and parathyroid – to remove calcium from our bones, causing osteoporosis in the long term and other problems in the near term.
“The body doesn’t like using these hormones and you’re going to have to pay back and there are various ways of payback,” says Thys-Jacobs. “First comes weakening of the bones, then high blood pressure and cancer risk – because of the excess hormones.”
So how do you keep from having to pay the price? Experts say people of all ages and both sexes have to be vigilant about keeping their calcium supply up to the standard. And they remind us that the source of calcium does not have to be milk.
Maudine Nelson, a registered dietitian at Columbia Presbyterian Medical Center in New York City, says you can find rich supplies of calcium in many foods.
“You can get calcium from tofu and leafy green vegetables,” says Nelson. “You get a little calcium in beans and you get calcium whenever you eat a canned fish in which there are still bones – such as sardines or salmon.” For those that need that little something extra, there are also supplements.
As people grow older, experts say they need to remain as conscious of their calcium intake because it plays a much bigger role than we ever knew in living better and living longer.