A study by Eliassen et al, published in The American Journal of Clinical Nutrition, found that high concentrations of dietary carotenoids were associated with 18–28% statistically significantly lower risks of breast cancer.
Carotenoids are found in many foods, such as squash, carrots, spinach, kale, tomatoes, grapefruit, oranges, and apricots.
The study’s conclusion: “In this large prospective analysis with 20 y of follow-up, women with high plasma carotenoids were at reduced breast cancer risk particularly for more aggressive and ultimately fatal disease.”