November 26, 2008 – Calcium supplement may increase bone density in men aged 40 and over, recent New Zealand study finds1.
Over the course of two years, 323 men aged 40 and over – an average of 57 years old – took daily doses of calcium (600 mg or 1,200 mg) or a placebo. The researchers measured the subjects’ bone density at the start, during and at the end of the clinical trial. According to the results, the dose of 1200 mg of calcium was associated with an increase of approximately 1% in the mineral density of the vertebrae after six months, and of the hip after two years. The 600 mg dose was ineffective.
Subjects in the placebo group showed no loss of bone density during this trial. A surprising result since it is normal for bones to weaken after the age of 40 and this result could mean that calcium intake is not the only factor that could affect bone health.
The authors also observed a slight, albeit statistically insignificant, increase in the number of cardiovascular disorders in subjects who took the 1200 mg calcium supplements. Recent preliminary data indicate that there may be a link between a high calcium intake and the risk of suffering from cardiovascular disorders.2.
Insufficient evidence
According to Guy Thibault3, research advisor at Kino-Québec who participated in the drafting of an opinion on bone health4, the effectiveness of calcium supplements in increasing bone density has not yet been clearly demonstrated. “The results of this new study contradict other studies. All the results accumulated to date leave one perplexed as to the possibility that an additional supply of calcium could, on its own, significantly reduce the number of fractures in people over 40 years of age. “
Recent research also confirms that the assiduous practice of certain types of exercises (running, jumping, weight training) contributes to increasing the resistance of the bones, says Guy Thibault. These exercises would also improve balance – and therefore prevent falls – as well as build muscles that protect bones during a shock and, therefore, reduce the number of bone fractures. “Current scientific data even allow us to state that an increase of the order of 1% in bone density resulting from adequate physical activity results in an increased bone strength of 10%. To my knowledge, there is no data indicating that the same is true for an increase in bone mass that occurs as a result of calcium supplementation, ”he explains.
Bone health depends on many factors, including one’s genetic makeup, vitamin and mineral intake, the latitude in which one resides (exposure to sunlight affects bone health) and physical activity. “Among these determinants, nutrient intakes and physical activity are the only ones on which we can concretely intervene at the clinical level in order to have a measurable effect on bone health,” adds Guy Thibault.
Pierre Lefrançois – PasseportSanté.net
According to Reuters Health.
1. Reid IR, Ames R, et al. Randomized controlled trial of calcium supplementation in healthy, nonosteoporotic, older men. Arch Intern Med. 2008 Nov 10; 168 (20): 2276-82.
2. Sailam V, Karalis DG, et al. Prevalence of Emerging Cardiovascular Risk Factors in Younger Individuals with a Family History of Premature Coronary Heart Disease and Low Framingham Risk Score. Clin Cardiol. 2008 Nov 12; 31 (11): 542-545.
3. Guy Thibault also holds a doctorate in exercise physiology and an advisor to the Department of Sport and Physical Activity of the Quebec Ministry of Education.
4. Physical activity and bone health. Opinion of the Kino-Québec Scientific Committee. Ministry of Education, Recreation and Sport, Canada, 2008. [Consulté le 17 novembre 2008]. www.kino-quebec.qc.ca.
