Current Status of Health Foods Including Their Interactions with Drugs and Adverse Events

Abstract

Although many people (and patients) in Japan currently consume health foods such as supplements, few have proper knowledge of their usefulness and safety. In December 2015, the Food Safety Commission of Japan issued a report and 19 messages mainly on the safety of health foods to disseminate appropriate knowledge to consumers. The report divided health food risks into three categories: 1) risks as food (e.g., increased lung cancer risk in smokers consuming excess β-carotenoid); 2) risks as health foods (e.g., short consumption history, drug contamination, poor quality of active ingredients, and interactions with drugs); and 3) risks due to a lack of adequate scientific information on health foods. The risk of insulin autoimmune syndrome caused by α-lipoic acid is relatively high among Japanese individuals because its onset is associated with HLA-DRB1*04:06, an HLA allele occurring frequently in East Asian populations. As for health food-drug interactions, an important pharmacokinetic interaction between drugs and St. John's Wort was described from several viewpoints: different effects on drugs within the same class (depending on the metabolic pathway); interindividual differences in its effects; importance of considering active metabolite involvement; and time course of interaction. An example of an interaction affecting drug efficacy was also introduced. Because the Japanese government now promotes a health-supportive pharmacy program in which pharmacies have a role in supporting the health of local patients/consumers, pharmacists are expected to acquire more scientific information on health foods, evaluate their evidence levels, and provide that information in plain language to patients/consumers.