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, according to data published in this month’s American Journal of Clinical Nutrition.
Researchers from Tufts University, Hebrew SeniorLife, and Boston University, studied data from 213 men and 390 women over the age of 75 participating in the Framingham Osteoporosis Study. The participants were followed for four years.
“These results suggest a possible protective effect of carotenoids, particularly of lycopene, against bone loss in older adults,” wrote the researchers, led by Katherine Tucker. “It is therefore possible that carotenoids explain part of the previously observed protective effects of fruit and vegetable intake on BMD.”
Bone health is becoming a major segment of the supplements and functional foods market, as ageing populations and the additional strain from obesity swell the numbers affected by osteoporosis. Already the lifetime risk for a woman to have an osteoporotic fracture is 30-40 per cent and in men the risk is about 13 per cent.
Study details
Tucker and her co-workers measured the intakes of total and individual carotenoids, including alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein plus zeaxanthin. Intakes were assessed using a 126-item food frequency questionnaire (FFQ). They then correlated this with the participants’ BMD at the hip, spine, and radial shaft.
At the end of study, the researchers noted a link between intakes of lycopene and the change over four years in the BMD of the lumbar spine in women. Moreover, this carotenoid was linked to changes in the hips of men. BMD in the hips of men was also associated with intakes of total carotenoids, beta-carotene, and lutein plus zeaxanthin, said the researchers.
Mechanism
The researchers proposed that the carotenoids may play a protective role in skeletal health via their antioxidant activity. Previous reports have suggested that oxidative stress may increase bone resorption. Other mechanisms may also be responsible for these effects, they added.
“The current study is unique in that it uses a large population-based cohort that included both elderly men and women,” wrote the researchers.
“In summary, although we observed few cross-sectional associations between carotenoid intakes and BMD, we observed several inverse associations between carotenoids (except for beta-cryptoxanthin and alpha-carotene) and four-year loss in BMD in men and of lycopene and bone loss at the lumbar spine in women.
“More studies are needed to examine these associations in other populations,” they concluded.
Source: American Journal of Clinical NutritionJanuary 2009, Volume 89, Number 1, Pages 416-424“Inverse association of carotenoid intakes with 4-y change in bone mineral density in elderly men and women: the Framingham Osteoporosis Study”Authors: S. Sahni, M.T. Hannan, J. Blumberg, L.A. Cupples, D.P. Kiel, K.L. Tucker