Food supplements: the good and the less good

Abstract

In this issue of Nutrafoods, two papers examine the use of food supplements from different viewpoints. Tavani et al., from the Mario Negri Institute in Milan (Italy), analysed the pattern of supplement consumption in non-agonist Italian athletes. Their paper shows the widespread use of a variety of substances, which is accompanied by expectations that are often irrational. Approximately 90% of athletes who participated in the survey think that supplement intake increases physical performance, whereas only 67% believe that similar results can be obtained by adopting a healthy diet. Performance-enhancing supplements (according to the survey participants) can be easily found in the market and are usually not prescribed or suggested by physicians. Their use is increasing, primarily among middle-aged subjects, and has now been adopted by almost all amateur athletes. More than 50% of subjects do not express safety concerns. Cicero et al., on the other hand, emphasise the important preventive actions of antioxidant-based supplements on age-related macular degeneration (AMD). This degenerative disease exhibits high prevalence and – currently cannot be effectively treated with drugs. In a controlled study, fairly high doses of vitamins C and E, beta-carotene and zinc reduced AMD progression by ~25% compared with placebo. In a subsequent study (AREDS-2), the addition of lutein and zeaxanthin further augmented the positive evolution of AMD. These two papers point to some critical aspects of the supplement field, which are worth reflecting upon. On one hand, the use (better yet, abuse) of supplements by amateur athletes shows how these products might be poorly utilised and poorly understood (including the underestimation of risk), and are part of a poorly controlled market. In turn, these poorly addressed issues might translate into potential health problems. On the other hand, some molecules available as food supplements might indeed contribute to overall well-being and health. This is particularly true for subjects whose dietary intake of such compounds is insufficient: one notable example stems from AREDS-2, in which subjects with lower circulating concentrations of the antioxidants being studied reaped larger benefits from supplementation. Indeed, this line of reasoning fits with the very notion of “supplementation”. The future of supplements and their market likely depends on making the right choices between these two somewhat alternative pathways.