Preventive research and interventive research: in favour of to act rather than to react.

Conventional wisdom knows that "prevention is better than cure". However, in the many cases where we do not understand how to cure or intervent, prevention is not only better but may be the only way to promote public health. As the principal basis for preventive action, this paper advocates to focus more on preventive rather than on interventive research. Preventive research, as defined here, aims to identify a determinant A in the environment which causes an undesirable health effect B in the human body. Preventive research ends when the critical nature of A is convincingly established and ways to avoid A are identified. Interventive research, as defined here, aims to understand and manipulate the chain from A to B within the human body. Examples of real (poliomyelitis, lung cancer, AIDS) and possible scourges (BSE) from the last and this century indicate that preventive research has delivered culprits but that interventive research could not-and likely will not-unravel the whole chain from A to B. Based also on conceptual considerations it is concluded that, while both research approaches are needed, a strategy with more emphasis on preventive research and taking action at an earlier stage may lead to more community success.