Supplementation with conjugated linoleic acid (CLA) prevented age-related bone loss in mice, says a new study that could offer a dietary therapy for protecting against the ever-growing threat of osteoporosis.
“Our present findings indicate that CLA has the potential to be a safe and economically feasible dietary supplement that could serve as an alternative medical approach to preventing bone loss associated with inflammation during ageing,” wrote lead author Md Mizanur Rahman in the Journal of Nutritional Biochemistry (doi: doi:10.1016/j.jnutbio.2006.08.002).
Bone health is set to become 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.
The new research, performed at the University of Texas Health Science Center at San Antonio, adds to previous studies into the potential benefits of CLA for bone health, with a study published in the Journal of the American College of Nutrition (Vol. 24, pp. 177-181) last year reporting a positive benefit for the acid in post-menopausal women.
How the research was done
Rahman and his colleagues used ten-month old C57BL/6 mice and fed them all a standard diet for two months before dividing them into two groups – one group consumed the standard diet with 10 percent corn oil, and the other group consumed the standard diet with 9,5 percent corn oil and 0,5 percent CLA (Clarinol).
CLA are found predominantly in dairy products such as milk, cheese and meat, and are formed by bacteria in ruminants that take linoleic acids – fatty acids from plants – and convert them into conjugated linoleic acids, or CLA.
Clarinol, produced by Lipid Nutrition, is derived from safflowers. It has two CLA isomers, known as trans-10 cis-12 and cis-15 trans-11, which are respectively responsible for the effects.
After 10 weeks of either diet, it was found that the CLA-fed mice had higher bone mineral density (BMD) in specific bone regions than corn oil (CO)-fed mice. This increased BMD was tied to a reduced activity of pro-inflammatory cytokines (such as tumour necrosis factor alpha (TNF-alpha), and interleukin-6 (IL-6)).
Lower fat, increased muscle
In agreement with other studies looking at the effects of CLA on weight, Rahman reports that the CLA-fed mice also had significantly lower fat mass and increased muscle mass, compared to CO-fed mice.
“By inhibiting osteoclastogenic proinflammatory cytokines, CLA not only prevents bone loss due to excessive osteoclastogenesis but also prevents accretion of fat mass and loss of muscle mass during ageing,” said Rahman. Osteoclasts are multicentred cells that degrade and reabsorb bone, and thereby weaken the overall bone.
“Indeed, our data warrant a clinical trial to show the efficacy of CLA on bone loss protection in ageing people,” said the researchers.
Rahman and co-workers also called for more studies with different CLA isomers ratios to investigate the safety and the mechanisms behind the observed effects.
“In conclusion, these findings suggest that CLA may prevent the loss of bone and muscle mass by modulating markers of inflammation and osteoclastogenic factors,” they said. - (Decision News Media, October 2006)