Joint supplement protects heart?

New research suggesting that regular use of glucosamine supplements may reduce the risk of cardiovascular disease (CVD) events has been met with scepticism by Australian experts.

Glucosamine is a popular dietary supplement used to relieve osteoarthritis and joint pain. While its effectiveness on joint pain continues to be debated, emerging evidence suggested that glucosamine may have a role in preventing cardiovascular disease and reducing mortality.

As conclusive evidence was lacking, researchers led by Professor Lu Qi at Tulane University in New Orleans drew on data from the UK Biobank — a large population-based study of more than half a million British men and women.

Their analysis included 466,039 participants without CVD, who completed a questionnaire on supplement use, including glucosamine.

Death certificates and hospital records were then used to monitor CVD events, including CVD death, coronary heart disease (CHD) and stroke, over an average seven-year follow-up period.

The researchers found that glucosamine use was associated with a 15% lower risk of total CVD events and a 9% to 22% lower risk of CHD, stroke and CVD death compared with no use.

These favourable associations remained after taking account of traditional risk factors, including age, sex, weight (BMI), ethnicity, lifestyle, diet, medication and other supplement use.

However, the results have been met by some scepticism.

"Results were expressed as relative risk, not absolute risk," said Associate Professor Ken Harvey AM of the school of Public Health and Preventative Medicine at Monash University. "This is potentially misleading, figures on absolute risk (CVD events, deaths, etc, per 1000 patients per year in glucosamine users compared to non-users) should also have been given."

A/Prof Harvey also said that glucosamine is no longer recommended for osteoarthritis.

Dr Louisa Lam, Deputy Dean of the School of Nursing and Healthcare Professions at Federation University, concurred.

"There [is so much controversy] around the effects of glucosamine and vitamin supplements in general, I do have doubt with the analysis. There [is] lots of research evidence [that] supports my doubt."

The study's authors acknowledged that, despite the large sample size, this is an observational study and, as such, can’t establish cause. They also point to some limitations, such as lack of information on dose, duration and side effects of glucosamine use.

As such, they conclude that "habitual use of glucosamine supplements to relieve osteoarthritis pain might also be related to lower risks of CVD events. Further clinical trials are warranted to test this hypothesis."

A/Prof Harvey doubts a clinical trial will go ahead. "It is unlikely that this study will be replicated and, in my opinion, a large-scale controlled clinical trial to test what is at best a dubious hypothesis is unlikely to get up."

The study has been published in The BMJ.

Image credit: ©stock.adobe.com/au/Von Schonertagen