The research demonstrates that although cohort studies — the type of observational investigations typically used to study health benefits and risks — sometimes show benefits from moderate alcohol consumption, they tend to enroll people age 50 and older. Studying people at this age range eliminates all those who have died before age 50 because of alcohol consumption.
Simply put, “deceased persons cannot be enrolled in cohort studies,” write the authors, led by Timothy Naimi, M.D., M.P.H., of the Boston Medical Center. “Those who are established drinkers at age 50 are ‘survivors’ of their alcohol consumption who [initially] might have been healthier or have had safer drinking patterns” compared with others.
