A Harvard study published online on June 13, 2016, in the journal Circulation found that, compared to people who didn't eat many whole grains each day, people who ate four servings of whole grains daily (about 70 grams) during the study period had a 22% lower risk of death from any cause, a 23% lower risk of dying from cardiovascular disease, and a 20% lower risk of dying from cancer. The study doesn't prove that whole grains prevent early death, but it adds to increasing evidence that whole grains really are full of "goodness."
Whole-grain kernels have three parts — the bran, endosperm, and germ — that give you phytonutrients, vitamins, and antioxidants, which protect against chronic disease. Refined grains get rid of the bran and germ in the processing, and you lose the fiber and many of the nutrients.
Many whole grains contain plenty of fiber, which helps lower cholesterol, improves digestion, and controls blood sugar.