Carotenoids are fat-soluble plant pigments responsible for the bright colors of fruits and vegetables. Some carotenoids can be converted by the body into vitamin A. The best-known example is beta-carotene, which also has the greatest vitamin A activity. Other carotenoids include alpha-carotene, lycopene, lutein, astaxanthin, beta-cryptoxanthin, and zeaxanthin.
Research published in Cancer Research (2009;69(24):9323–9329) compared 602 women with breast cancer to 626 healthy controls and examined circulating blood levels of carotenoids. The study found an inverse relationship between carotenoid levels and breast cancer risk.
The association was strongest in women with high mammographic breast density. In this group, higher circulating carotenoid levels were associated with up to a 50% lower risk of breast cancer. This protective relationship was not observed in women with low mammographic density, suggesting that carotenoids may be particularly relevant in higher-risk populations.
