Processed grains, like those in white flour, don’t contain the whole grain kernel—but it’s the whole grain that contains all the nutrients. The bran and germ bits include nutrients like vitamin E, copper, zinc, and selenium, plus lignans and phytoestrogens that researchers think could have anti-carcinogenic properties. They’re also full of fiber, which feeds healthy gut bacteria, ferments into short-chain fatty acids that may help prevent cancer, and move your bowel contents faster (which may decrease the chances that a cancer causing agent in your feces comes in contact with your intestinal cells).

Diets low in whole grains( tend to promote inflammation and )lead to an unhealthy gut overall, which is why they’re primarily associated with colorectal cancer.