Dale A. Cooper, Ph D, Alison L. Eldridge, Ph D., R.D., John C. Peters, Ph D; Dietary Carotenoids and Lung Cancer: a Review of Recent Research. Nutr Rev 1999; 57 (5): 133-145. doi: 10.1111/j.1753-4887.1999.tb01794.x
Several hundred carotenoid research studies have been published since 1996, when two major intervention trials showed a lack of protective effect of β-carotene supplements against lung cancer. Recent epidemiologic studies continue to show an association between high dietary intake of β-carotene and lower risk of lung cancer. New research is attempting to clarify the apparently contradictory results of intervention and epidemiologic studies. Promising areas of investigation include characterizing biologic activities of carotenoids and gaining further insight into whether they may serve primarily as markers for a healthy lifestyle or diet.