A new study has revealed that 75% of healthy Australians aged over 70 years report using complementary medicines either daily or occasionally – sparking concerns over the marketing and promotion of these medicines, and renewed calls for tighter regulation of the industry.

Lead researcher and Senior Research Fellow at Monash University, Dr Alice Owen, said that “one major concern is the issue of people potentially spending a lot of money for little benefit.”

“Another concern we have is that it appears that almost half of people don’t tell their doctor about their complementary medicine use”, she told HealthTimes.

“As a result, it will be harder to pick up when there is a risk of adverse interaction between complementary medicines and other medicines prescribed by their doctor.”

Dr Owen and her fellow researchers analysed data from the ASPirin in Reducing Events in the Elderly (ASPREE) Longitudinal Study of Older Persons (ALSOP) to assess self-reported use (every day, occasionally, never) of complementary medicines by healthy people over 70 years of age residing in metropolitan or regional Victoria, South Australia, Tasmania, the Australian Capital Territory or southern New South Wales, recruited through their usual GPs.

Specifically, they asked about the use of fish oil, glucosamine, ginkgo, coenzyme Q10, calcium, zinc, vitamins B, C, D and E, multivitamins, and Chinese or herbal medicines.

“A total of 10 961 respondents (74.3%) reported using them either daily or occasionally; fish oil (6563 of 14 757 respondents, 44.5%), vitamin D (4995, 33.8%), glucosamine (3940, 26.7%), and calcium supplements (3652, 24.7%) were the most frequently reported items,” the authors found. 

Dr Owen said that the use of vitamin D among healthy older adults was not surprising. “We know from previous Australian Health Surveys (from the Bureau of Statistics) that in southern states, and particularly in winter, rates of vitamin D deficiency can be as high as 50%”

“We were a little more surprised by the common use of fish oil, glucosamine and multivitamins. These are complementary medicines for which the evidence base for health benefit is more limited, so more likely to be personal choice rather than
being ‘prescribed’ by a doctor.”

Dr Owen said that the risk of adverse interactions with prescription medicines was not the only concern to be raised by the study. 

“As supplements bought over the counter in Australia are regulated by the Therapeutics Goods Administration (TGA) for safety, we are not concerned about the ingredients of these supplements being unsafe.”

“What we are more concerned about is that people living on constrained income – and older adults are often living on fixed incomes – might be spending money on some supplements for which they may attain little or no health benefit.”

There are several driving factors behind the popularity of complementary medicines among older Australians.

“I think people generally have trust in the TGA for ensuring the safety of complementary medicines they buy over the counter in Australia. There may also be a perception that complementary medicines are more ‘natural’ than pharmaceuticals, and this may appeal to some people.”

She said the lack of pharmaceutical treatment options for common conditions affecting older people, such as osteoarthritis, was also a contributing factor. 

“If people have sore joints and are not getting satisfactory pain relief, it is understandable that they might explore other options – for example, we expect this would be the reason that people in our study chose to take glucosamine.”

“The issue is that there is not strong evidence that glucosamine can effectively treat joint pain – the clinical trials of glucosamine have been very inconsistent and results are controversial. And because of the way complementary medicines are regulated, it is unlikely that people standing in front of a shelf of glucosamine at the chemist will know of this inconsistent evidence.”

The results of the study led the researchers to express concern about the marketing and promotion of complementary medicines.

“My personal opinion is that there should be greater regulation of health claims made by complementary medicines, with evidence supporting health claims subject to mandatory review by regulators, and this made available to consumers”, Dr Owen explained.

“This would mean extra resourcing of the regulator, but when ‘Vitamins and Dietary Supplements’ is a $3 billion dollar industry in Australia in 2019 and we have so many Australians choosing to use complementary medicines, that would seem (to me) to be a worthwhile investment.”