GMAT Critical Reasoning (CR) | Re: Multivitamins and Antioxidants

Nutritionist: Multivitamins are potent storehouses of antioxidants, substances that fight the oxidation process, which breaks down the body. Nonetheless, according to longitudinal studies—studies that follow subjects over the course of many years—those who take multivitamins every day have a decreased longevity. Clearly, if people want to live longer they should avoid antioxidants.


Which of the following is an assumption the argument relies on?

a)