When it comes to foods that lower cancer risk, color may count.
Researchers report in the Journal of the National Cancer Institute that women loading up carotenoids, the micronutrients found in red, yellow and deeply colored fruits and vegetables such as carrots, sweet potatoes spinach and kale, showed lower rates of breast cancer than those who didn’t eat as many of these foods.
Previous studies looking at the link between carotenoid levels and breast cancer had varying results, with some reporting high levels associated with a reduced cancer risk and others finding no such link. Dr. Heather Eliassen, assistant professor of medicine at Harvard Medical School and her colleagues analyzed the data from eight cohort studies that cover over 80% of currently published research on carotenoids in the blood and breast cancer rates.
The researchers took the data, which covered over 3,000 participants and nearly 4,000 controls, and standardized the carotenoid levels measured in the blood by re-analyzing the participants’ blood samples at the Harvard School of Public Health.
Women with carotenoid levels in the the top 20% of measured ranges had a 15-20% reduced risk of breast cancer compared to those with carotenoid levels in the lowest category. “It looks like it is a linear relationship,” says Eliassen. ”The higher you go, the your risk is. There is some benefit at a moderate level of carotenoids and there is even more benefit at a higher level.”
Read more: Alexandra Sifferlin, Time
