The compound quercetin, present in large amounts in apples, may help prevent prostate cancer, according to researchers at the Mayo Clinic, in Rochester, Minnesota.

Research published in the Carcinogenesis journal explained how the compound appears to prevent the changes that make prostate cells cancerous, blocking the cancer-promoting properties of the male hormones.

It also seems to slow the speed at which the cancer spreads and the scientists foresee that quercetin will become a part of cancer treatment in the future.
 
Quercetin can also be found in large amounts in onions, tomatoes, black tea, garlic, peppers, berries and grapes.