28 May 2013, BioSpectrum Bureau , BioSpectrum
Singapore: Research conducted by scientists at the College of Osteopathic Medicine, University of New England in Biddeford, UK, has highlighted that glucosamine supplements, which are used by bodybuilders to strengthen their joins and connective tissue, may increase risk for developing glaucoma. The findings are published online as a research letter in JAMA Ophthalmology.
In the new study of 17 people, whose average age was 76 years, 11 participants had their eye pressure measured before, during and after taking glucosamine supplements. The other six had their eye pressure measured while and after they took the supplements. Overall, pressure inside the eye was higher when participants were taking glucosamine, but did return to normal after they stopped taking these supplements, the study showed.
Exactly how glucosamine supplements could affect pressure inside the eye is not fully understood, but several theories exist. For example, glucosamine is a precursor for molecules called glycosaminoglycans, which may elevate eye pressure. Moreover, the researchers did not have information on the dose or brand of glucosamine used, and they did not know how long some participants were taking the supplements.
Dr Ryan Murphy, who led the research, said that, "This study shows a reversible effect of these changes, which is reassuring. However, the possibility that permanent damage can result from prolonged use of glucosamine supplementation is not eliminated. Monitoring IOP in patients choosing to supplement with glucosamine may be indicated."
Dr Duffy MacKay, vice president, scientific and regulatory affairs, Council for Responsible Nutrition, US, said that, "This research letter raises questions and introduces a hypothesis that should be explored further, but the small number of cases investigated and the [fact that] researchers did not count capsules or control for dose or intake or duration of use of glucosamine provide extremely limited evidence of harm."