Herbal supplement use by persons aged over 50 years in Britain - Frequently used herbs, concomitant use of herbs, nutritional supplements and prescription drugs, rate of informing doctors and potential for negative interactions

Background: The use of herbal and nutritional supplements by older British people is increasing and despite the risks of adverse effects and negative herb-drug interactions, doctors are often not informed of their use. The number of herbal and nutritional supplements used most frequently by older people, and which particular herbal extracts are used, are unknown. This study aimed to identify how many herbal and nutritional supplements and which herbal extracts are most frequently used by British people >50 years of age, and to identify which herb-drug interactions represent the greatest risk to this age group. Method: A self-completed survey was promoted through websites and a popular magazine aimed at people >50 years of age. Results: Respondents (n = 271) used a mean of 2.26 prescription drugs and 5.91 herbal and nutritional supplements, including 2.66 herbal extracts. The use of herbal medicines by older British people frequently involves the use of several herbs, often involves concomitant use with several nutritional supplements, is poorly reported to doctors and places older people at risk of negative herb-drug interactions. The most frequently used herbs and associated risks of negative interactions with prescription drugs are identified. Conclusions: Older people should be encouraged to report the use of herbs and nutritional supplements to their doctors, and doctors should be provided with comprehensive and up-to-date information about potential herb-drug interactions.