ABSTRACT
The dietary vitamin and supplement industry is one of the world’s fastest growing markets, with 32 billion dollars in revenue for nutritional supplements alone. Subjects taking nutritional supplements such as antioxidants expect ‘truly’ benefcial effects. Such an expectation may sometimes provoke substantial placebo effects which are often misinterpreted as true effects. Nutritional studies typically compare the efficacy of a new preparation with another and/or a placebo. Vitamin E is one of the most important nutritional antioxidants accounting for membrane stability and fluidity by preventing lipid peroxidation. Descriptive studies, also referred to as observational studies, collect information on existing relationships, for example, between health status or level of performance and the regular intake of antioxidants. The number of antioxidants presented in the scientific literature and on the market is countless, including substances such as colostrum, caffeine, selenium, carotenoids such as β-carotene, lycopene, lutein, zeaxanthin, coenzyme Q and many others.
