July 10, 2006

Calcium May Help Women Keep Weight in Check

By Anne Harding

NEW YORK (Reuters Health) - Getting plenty of calcium might help fight middle-aged spread, a new study shows.

Women in their 50s who took in more than 500 milligrams of calcium daily in supplements gained 4 pounds less over 10 years than women who didn't use supplements, Dr. Alejandro J. Gonzalez of the Fred Hutchinson Cancer Research Center in Seattle and colleagues found.

But Gonzalez told Reuters Health it would be "going out on a limb" to recommend calcium as a weight maintenance aid based on his study. Randomized clinical trials are necessary to determine whether calcium really is responsible for limiting weight gain, he added.

There is evidence that calcium can help people stay slimmer, Gonzalez and his colleagues note in the July issue of the Journal of the American Dietetic Association, but it is not conclusive. The most convincing explanation for how calcium might exert such effects, Gonzalez told Reuters Health, are studies showing that low calcium intake boosts the amount of calcium contained within cells, which in turn switches on genes involved in fat formation while inhibiting fat breakdown.

To further investigate the relationship, Gonzalez and his team looked at weight gain and calcium intake over an 8- to 12-year period in 10,591 men and women aged 53 to 57.

While calcium intake had no relationship with weight gain in men, the women who consumed more than 500 milligrams of calcium in the form of supplements gained 5.1 kilograms, or 11.2 pounds, over 10 years, compared to 6.9 kilograms or 15.2 pounds for those who didn't take calcium supplements.

"Although more evidence from randomized clinical trials is needed before calcium supplements can be recommended specifically for weight loss, this study suggests that calcium supplements taken for other reasons (e.g., prevention of osteoporosis) may have a small beneficial influence on reducing weight gain, particularly among women approaching midlife," Gonzalez and his colleagues conclude.

SOURCE: Journal of the American Dietetic Association, July 2006.