Calcium Supplements and Cholesterol Levels in Women
Women taking calcium supplements to protect bone health may improve their cholesterol levels as well, according to a new clinical trial published in the American Journal of Medicine.1
In this new study, 223 postmenopausal women were randomly assigned to take a placebo or 1,000 mg of calcium each day for one year. At the beginning and the end of the intervention, researchers measured the blood levels of the participants’ total cholesterol, low-density lipoprotein (LDL) cholesterol (known as “bad” cholesterol), and high-density lipoprotein (HDL) cholesterol (known as “good” cholesterol).
After one year of taking calcium, HDL cholesterol levels had increased by 7% compared with the levels before supplementation. HDL cholesterol increased significantly more in the women taking calcium than in those taking the placebo. There were slight reductions in total cholesterol and LDL cholesterol, as well, but these were not statistically significant.
Although the dangers of high cholesterol are well understood by the public, comparatively little attention has been paid to the dangers of low HDL cholesterol. In some people, low HDL cholesterol may be more important than high total cholesterol as a risk factor for heart disease.2 One study found that a 6% increase in HDL cholesterol (similar in magnitude to that reported here) led to a 22% reduction in the incidence of fatal and nonfatal heart attacks.3 In addition to calcium supplementation, supplementing with niacin, losing weight, engaging in aerobic exercise, and quitting smoking may help increase HDL cholesterol concentrations.4 5 6
Some double-blind trials have concluded that supplemental calcium reduces cholesterol levels.7 8 However, previously, the largest and best-designed clinical trial that studied the effects of calcium supplementation on cholesterol found no statistically significant effects on total cholesterol or HDL cholesterol after four months of supplementation.9
The ability of the new trial to demonstrate a statistically significant improvement in HDL cholesterol levels may be a result of a better design quality, a longer duration, and a larger group of participants than in the prior studies.
As the results of the ongoing clinical trials studying the effect of long-term calcium supplementation on bone health are published in the next decade, the question of whether years of calcium intake will have a positive impact on heart disease risk will likely be more directly addressed. Additional studies will be necessary to determine whether men taking calcium supplements would receive the same benefit as women.
Calcium supplements have been associated with better bone health in many studies.10 Since it appears that calcium can also increase HDL cholesterol levels, widespread supplementation by postmenopausal women appears more justified than ever.
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4. Guyton JR, Blazing MA, Hagar J, et al. Extended-release niacin vs gemfibrozil for the treatment of low levels of high-density lipoprotein cholesterol. Niaspan-Gemfibrozil Study Group. Arch Intern Med 2000;160:1177–84.
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6. Dwyer JH, Rieger-Ndakorerwa GE, Semmer NK, et al. Low-level cigarette smoking and longitudinal change in serum cholesterol among adolescents. JAMA 1988;259:2857–62.
7. Bell L, Halstenson CE, Halstenson CJ, et al. Cholesterol-lowering effects of calcium carbonate in patients with mild to moderate hypercholesterolemia. Arch Intern Med 1992;152:2441–4.
8. Karanja N, Morris CD, Illingworth DR, McCarron DA. Plasma lipids and hypertension: response to calcium supplementation. Am J Clin Nutr 1987;45:60–5.
9. Bostick RM, Fosdick L, Grandits GA, et al. Effect of calcium supplementation on serum cholesterol and blood pressure. Arch Fam Med 2000;9:31–9.
10. Welten DC, Kemper HC, Post GB, van Staveren WA. A meta-analysis of the effect of calcium intake on bone mass in young and middle aged females and males. J Nutr 1995;125:2802–13.
Matt Brignall, ND, is in practice at the Seattle Cancer Treatment and Wellness Center and at the Evergreen Integrative Medicine Clinic in Kirkland, WA. He specializes in integrative treatment of cancer. He is a contributor to Healthnotes and Healthnotes Newswire.
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