Women who have substantial intake of carotenoids in their diets have lower risks of breast cancer and breast cancer recurrence than women with low intake. Carotenoids are red, orange, and yellow pigments found in a variety of vegetables and fruits. Included are alpha-carotene, beta-carotene, lycopene, beta-cryptoxanthin, lutein, and zeaxanthin, as well as some less well known carotenoids such as crocetin (found in saffron) and fucoxanthin (seaweed). Mixtures of carotenoids are often found together in the same plant. Although the evidence is inconsistent, supplementation with carotenoids does not appear to reduce breast cancer risk and might in fact increase it in some cases. Now a new meta-analysis of previous prospective studies has reported that women with relatively high levels of circulating carotenoids have a 19% lower risk of breast cancer compared to those with low levels.
Latest research finds carotenoids linked to lower breast cancer risk
The meta-analysis referenced at the beginning of this news article was designed to investigate the associations between circulating carotenoid levels and breast cancer risk. To conduct the analysis, the authors performed a pooled analysis of eight prospective studies concerning circulating carotenoids and risk of breast cancer. The studies included a total of 3,055 breast cancer cases and 3,956 matched cancer-free controls. To ensure that the data was comparable across the eight studies, the authors recalibrated study participant carotenoid levels to a common standard by retesting 20 plasma or serum samples from each study at the same laboratory.
Women in the top fifth (quintile) of total circulating carotenoids were found to have a 19% lower risk of breast cancer compared to those in the lowest quintile. When carotenoids were considered individually, women in the top quintile of lycopene were found to have a 22% lower risk of breast cancer than those in the bottom quintile. The comparable reductions in risk were 17% for high levels of beta-carotene, 16% for lutein+zeaxanthin (which are often found together in foods), and 13% for alpha-carotene. Beta-cryptoxanthin was not found to be significantly associated with breast cancer risk.
The link to lower breast cancer risk was found to be stronger for estrogen receptor negative (ER-) than for ER+ disease for several carotenoids. For example, high levels of beta-carotene were associated with a 48% lower risk of ER- breast cancer compared to a 17% lower risk of ER+ breast cancer. The authors conclude that women with relatively high circulating levels of alpha-carotene, beta-carotene, lutein and zeaxanthin, lycopene, and total carotenoids may be at reduced risk of breast cancer.
Please see our article on how to optimize your breast cancer diet for information on what to eat during all stages of treatment and recovery.