ABSTRACT

Each research discipline makes a critical contribution to the totality of evidence that permits the evaluation of risks and benefits of agents such as antioxidants (1). Advances in medical knowledge proceed on several fronts, optimally simultaneously. First, basic researchers provide unique and crucial information about mechanisms that explains why a particular agent averts premature death or disability. Second, clinicians provide enormous benefits to patients through advances in diagnosis and treatment and, in addition, formulate hypotheses from their own clinical experiences-i.e., case reports and case series. Clinical investigators test the relevance of basic research to healthy individuals and approved patients. Finally, epidemiologists and biostatisticians formulate hypotheses from descriptive studies and test hypotheses in observational studies, either case-control or cohort, or, where necessary, in randomized trials to answer the unique and crucial question of whether a particular agent can prevent premature death or disability.