Research published in the British Journal of Nutrition discovered that the risk of breast cancer decreases with increased consumption of specific dietary carotenoids, the color pigments in some vegetables and fruits.

The research was based on five years of tracking 1,122 women in Guangdong, China; half of them had been diagnosed with breast cancer and the other half were healthy. Dietary intake information was collected through face-to-face interviews. The women that consumed more beta-carotene in their diet showed a 46 percent lower risk of breast cancer, while those that consumed more alpha-carotene had a 39 percent reduced incidence. The individuals that consumed more foods containing beta-cryptoxanthin had a 62 percent reduced risk; those with diets higher in luteins and zeaxanthins had a 51 percent reduction in breast cancer risk.

The scientists found the protective element of increased carotenoid consumption more evident among pre-menopausal women and those exposed to secondhand smoke.

Dark green leafy vegetables such as kale, spinach and dandelion greens top the list of sources rich in luteins and zeaxanthins, which also includes watercress, basil, parsley, arugula and peas. The highest levels of beta-carotene are found in sweet potatoes, grape leaves, carrots and kale, spinach, collard and other leafy greens. Carrots, red peppers, pumpkin, winter squash, green beans and leafy greens contain alpha-carotene. Red peppers, butternut squash, pumpkin persimmons and tangerines are high in beta-cryptoxanthin.