Diabetes has been found to increase the risk of Alzheimer's disease but it is unclear what effect it has on people who already have the condition. Researchers from the French National Institute for Health and Medical Research in Toulouse followed 608 people with mild-moderate Alzheimer's for four years and tested their memory and thinking skills twice a year. 63 of the sample had diabetes. The study found that the participants with diabetes actually declined less over the course of the study. The researchers thought that the participants with diabetes might also be taking medicine for cardiovascular problems improving their circulation and helping to mitigate some of the effects of Alzheimer's.