What do herbalists suggest to diabetic patients in order to improve glycemic control? Evaluation of scientific evidence and potential risks.
In the course of 12 continuing education seminars given in different regions of Italy in 2001, we distributed a questionnaire to all the attending herbalists asking information about the herbal remedy and dietary supplement they mainly recommended to subjects who required a "natural" treatment to control glycemia. We distributed 720 questionnaires and we received 685 completed ones. We have compiled a short review on the efficacy and safety of the 10 most frequently advised products for each category. The 10 more frequently suggested herbal remedies were gymnema, psyllium, fenugreek, bilberry, garlic, Chinese ginseng, dandelion, burdock, prickly pear cactus, and bitter melon. The 10 most frequently recommended dietary supplements were biotin, vanadium, chromium, vitamin B6, vitamin C, vitamin E, zinc, selenium, alpha-lipoic acid, and fructooligosaccharides. The majority of the products recommended by Italian herbalists may be efficacious in reducing glycemia. If a diabetic patient is already assuming products that even slightly reduce glycemia, we risk to underestimate the level of glucose intolerance, while if the patient stops the complementary treatment after initiating pharmaceutical therapy, in the subsequent visit we may underestimate the effect of our prescription. Therefore, if doctors are to have a role in gate-keeping or advising patients about complementary and alternative medicine, they need to be familiar with this type of medicine. If they choose otherwise, then the provision of complementary and alternative medicine will continue to be patchy and largely outside the conventional care framework, perhaps through a growing network of parallel care providers involving a large number of non-medically qualified practitioners, who patients will continue to access directly.