Antioxidants plus exercise may boost bones in older women
Women receiving a combination of vitamins C and E, and exercise did not experience any bone loss during a six-month period, while women receiving placebo did experience detrimental bone loss, according to findings published in Osteoporosis International.
“These results are interesting because this is the first study to examine the combination of these interventions in healthy elderly women suggesting another effective strategy to delay age-related BMD loss,” wrote the researchers, led by Isabelle Dionne, PhD, from the University of Sherbrooke.
However, the researchers cautioned that, since this is a pilot study, it would be inappropriate to make “formal nutritional recommendations”.
“Further research is needed to determine appropriate recommendations for this population especially since nutrition and exercise are two effective and accessible strategies towards health maintenance in the aging population,” they added.
Osteoporosis is characterized by low bone mass, which leads to an increase risk of fractures, especially the hips, spine and wrists. An estimated 75 million people suffer from osteoporosis in Europe, the USA and Japan.
Women are four times more likely to develop osteoporosis than men.
The bare bones of the study
Dionne and her co-workers recruited 34 postmenopausal women with an average age of 66.1, and an average BMI of 25.98 kg/m2, and randomly assigned them to one of four groups: placebo and no exercise; antioxidants (600 mg vitamin E (dl-alpha-tocopherol) and 1,000 mg vitamin C daily) and no exercise; placebo plus exercise; and antioxidants plus exercise, for 6 months.
Measures of the bone mineral density (BMD) of the hip (femoral neck) and spine (lumbar spine) revealed that only the placebo and no exercise group experienced significant bone loss at the lumbar spine. The BMD of both sites remained constant in all the other groups. No additional effect was observed when antioxidants were combined with exercise.
Commenting on the possible mechanism, Dionne and her co-workers stated that a previous study has indicated a decrease in bone resorption following antioxidant supplementation.
“Antioxidants may reduce the damaging effects of oxidative stress on bone mass by reducing the up-regulated osteoclastic differentiation and enhancing the down-regulated osteoblastic differentiation,” they said. Osteoclasts are cells which break down bone, leading to resorption and weakening.
“Our results suggest to further investigate the impact of antioxidant supplements on the prevention of osteoporosis,” they concluded.
Antioxidants and bones
Earlier this year, a study funded by the USDA’s Agricultural Research Service reported that an increased intake of carotenoids, and particularly lycopene, was associated with some level of protection against losses in bone mineral density (BMD) at the lumbar spine in women and at the hip in men.
Writing in the January 2009 issue of the American Journal of Clinical Nutrition, researchers from Tufts University, Hebrew SeniorLife, and Boston University, stated: “It is therefore possible that carotenoids explain part of the previously observed protective effects of fruit and vegetable intake on BMD.”
Source: Osteoporosis International July 2009, Volume 20, Number 7, Pages 1253-1258“Effect of antioxidants combined to resistance training on BMD in elderly women: a pilot study” Authors: A. Chuin, M. Labonté, D. Tessier, A. Khalil, F. Bobeuf, C. Y. Doyon, N. Rieth and I. J. Dionne
