When evaluating the efficacy of foods with health claims (FHC), each country sets different standards for efficacy evaluation endpoints in clinical trials, which may result in a barrier, namely the case that the claim that is allowed in Japan cannot be used on the label in another region and vice versa. We aimed to investigate the efficacy evaluation endpoints used in clinical trials of FFCs containing ID and submitted in Japan, in reference to the EU requirements for substantiating the claim, namely "reduction of post-prandial glycemic responses". We detected only one difference in efficacy evaluation endpoints, which was insulin levels. We found 67 such clinical trials cited in systematic literature reviews on finished products or functional substance(s). Of these, 43 (64%) trials lacked insulin assessment. Particularly, for foods that were claimed to reduce post-prandial glycemic responses, the EU does not consider a claim to be substantiated unless insulin levels have been evaluated. Our findings suggest the need for standardization of requirements for FHC between Japan and the EU. This consideration will strengthen the evidence for clinical significance of ID and allow products labeled with this health claim to be more widely distributed.
Keywords: Clinical trial; Japan; efficacy evaluation; foods with functional claims; indigestible dextrin; post-prandial glycemic response.