PITTSBURGH, Penn. --New research shows eating fish is tied to a dramatic drop in the risk of Alzheimer's. Doctors at the University of Pittsburgh Medical Center said people who eat fish at least once per week are three to five times less likely to develop Alzheimer's disease and a related condition known as mild cognitive impairment. Doctors believe regular fish consumption makes neurons in the gray matter of the brain larger and healthier. Only baked and broiled fish showed the benefit -- fried fish did not.