Vegetables appeared to offer more cancer prevention than fruits alone did. Adding just one serving of fruit or vegetables per each 1000 calories consumed daily resulted in a 6% reduction of risk.
In another study, broccoli and soy protein were found to protect against the more aggressive breast and ovarian cancers. When consumed together, digesting broccoli and soy forms a compound called di–indolylmethane (DIM). In lab experiments, the researchers found that DIM could affect the motility of breast and ovarian cancer cells, which could help keep cancers from spreading. Soy, acts like estrogen and is a nutritious, healthy food, and should be eaten in moderation.
Yet another study compared intake of flavonols to their risk of pancreatic cancer. Flavonols are protective compounds found in fruits and vegetables, such as onions, apples, berries, kale and broccoli. Those who had the highest consumption of flavonols reduced their risk of pancreatic cancer by 23%. The benefit was even greater for people who smoked. Smokers with high levels of flavonols reduced their risk of pancreatic cancer by 59%.