What substance is linked to an increased incidence of lung cancer in smokers, according to AREDS1?

Beta-carotene is linked to an increased incidence of lung cancer in smokers according to the Age-Related Eye Disease Study (AREDS1). This finding arises from observations made during the study, where the supplementation of beta-carotene in smokers not only did not provide the expected health benefits but was associated with a higher risk of developing lung cancer. This adverse effect is particularly important because it highlights the potential dangers of high-dose vitamin A precursors like beta-carotene in populations that smoke, illustrating the complex interactions between certain nutrients and health outcomes in specific groups.

The significance of this finding has influenced recommendations for nutritional supplementation in populations at risk, especially in smokers, emphasizing the importance of context in nutritional science. Vitamins A and E, as well as zinc, did not show this same negative correlation with lung cancer risk in the study, indicating that not all supplements carry the same risks or benefits in relation to the incidence of malignancies.