[Effect of flavonoids in the prevention of lung cancer: systematic review]

For years, lung cancer has been the tumor causing more deaths in industrialized and emerging countries. A meticulous care of the nutritional aspects, with emphasis on high consumption of fruits and vegetables, can be an important element of primary prevention. Taking into account research on the effect of substances with antioxidant power, many epidemiological studies have focused on flavonoids. The objective of this review is to analyze the available scientific evidence in the literature regarding the role of flavonoids in lung cancer. After a systematic literature review, we identified a meta-analysis, a systematic review, 11 prospective cohort studies and 5 case-control studies. After reviewing the scientific evidence provided by these works, there was a small protective effect of flavonoid consumption (especially at high doses) against the development of lung cancer, although not all studies confirmed it. There seems to be no differences between selective intake of different types of flavonoids and consumption of total flavonoids, but there are differences between the different populations studied.