People who have both Alzheimer's disease and diabetes have slower rates of memory loss than people who just have Alzheimer's, French researchers said on Tuesday.
They studied 600 Alzheimer's patients for four years and found those who had both Alzheimer's and diabetes - about 10 percent of the total - scored far better on twice yearly memory and thinking tests than those with Alzheimer's who did not have diabetes.
"This result was surprising," said Dr. Caroline Sanz of the French National Institute for Health and Medical Research, whose study appears in the journal Neurology.
"Our initial hypothesis was that diabetes would increase the rate of cognitive decline in people with Alzheimer's disease," she said in a statement.
Prior studies have suggested that diabetics are at higher risk for developing Alzheimer's disease. Sanz and colleagues wanted to see if diabetes influences the rate of mental decline in people who already have mild to moderate Alzheimer's.