A review of previous studies found that none tested whether eating whole grains influences the risk of death from heart disease, or the risk of a heart attack or a stroke. They did assess the impact of whole grains on risk factors for heart disease, such as blood pressure and cholesterol. But none found any differences based on the types of grains people ate. A large, undisputed body of evidence associates whole grains with other health benefits, however, including lower weight gain, better cholesterol, glucose and insulin levels, which are risk factors for heart disease. They are also a source of cereal fiber that has been linked to lower risk for heart disease, obesity and cancer.