People with diabetes are risking their health by not discussing their use of complementary and alternative therapies with the health professionals managing their conventional treatment.
A review of the international health literature has shown nutritional supplements and herbal medicines are the most commonly used complementary and alternative therapies in diabetes.
Annie Chang, a PhD candidate in Griffith's School of Nursing, said while some products may have benefits for patients, they can also have side effects in their own right or interact with conventional medications.
"Fenugreek for example, used as a supplement, may affect blood sugar levels but patients are already on other blood sugar lowering medications as well."
While the prevalence of use varies widely between different countries (17-72%), her review suggests nearly half of people living with diabetes supplement their conventional medicines with some form of alternative therapy.
Women, over 65-year-olds, those who had been living with diabetes for longer, and people interested in self management of their condition were the most likely to use alternative therapies.
"People will tell their alternative practitioners that they are using Western medicines but the vast majority will not discuss their alternative therapies with a doctor or other healthcare professional," she said.
Ms Chang, who has also surveyed more than 300 diabetics in Taiwan, said people feared their doctor would not be interested in discussing alternative medicines or that they might 'get into trouble' for taking them.
"The evidence is that patients are using these products and may even reduce their conventional medicine doses and modify the timing of doses so they aren't taking both together."
"While it might be impossible for Western medicine to learn all about complementary and alternative therapies, healthcare professionals do need to be included in discussions about them so we can document their use and be aware of any potential problems for our patients."
The review was published in the Journal of Advanced Nursing 2007; 58(4) 307-319.
National Diabetes Week is 8-14 July.