Nutrition Studies with Human Volunteers, Designs and Compliance to Good Clinical Practice

抄録

In vitro experiments with cell cultures, studies with the TNO gastrointestinal model, animal experiments, and studies with human volunteers are used in nutrition research on the assessment of efficacy and safety of ingredients that can be used as bio actives in functional foods, functional drinks and dietary supplements. Human volunteer studies are considered to be the final and decisive step in these different types of studies. In fact health claims should not be used without demonstration of efficacy in human volunteer studies. For such studies many issues are important to arrive at valid conclusions: selection of eligible volunteers (inclusion- and exclusion criteria, medical examination), measurement of validated bio markers, check of compliance, measurement of safety parameters, application of documented standard operation procedures etc. Attention should also be given to selection of the most appropriate study design. Ideally, a randomized double blind parallel- or cross over design placebo-controlled is preferred. Special attention should be given to the number of volunteers participating in the study to have adequate statistical power and thus reduce the risk of type II statistical errors. No study should be started without prior power calculation. In nutrition studies with humans also the dose-effect relationship should be addressed. Selection of suitable (realistic) doses of the bio active substance is critical. Moreover attention should be given to potential matrix effects in the food, drink or supplement, that could influence bio availability and/or bio efficacy. A detailed protocol for the study should be developed. The protocol should be approved by a Medical Ethics Committee. Candidate volunteers should receive both written and oral information on the study and to be eligible they should sign consent forms.