Type 2 diabetes is a known risk factor for dementia. Although the underlying mechanisms are not fully understood, scientists believe that some of the hallmarks of diabetes, such as high blood sugar, insulin resistance, and inflammation, may contribute to neurodegeneration. Two decades ago, type 2 diabetes was considered a disease of the elderly, but now at least one in five people is diagnosed before the age of 40.
In a new study, researchers at New York University followed more than 1,200 Americans over 14 years, all of whom were 50 at the start of the experiment. By the end, 18 percent had dementia.
It turned out that having a history of type 2 diabetes before age 50 increased the risk of dementia by 1.9 times.
If diabetes was diagnosed between 50 and 70 years of age, the likelihood of dementia was 1.7 times higher. The greatest risks were in people with obesity.
"These new findings linking dementia and diabetes support the need for further research and development of new methods for preventing dementia," the authors said. They recommend weight control and dietary modifications for all at-risk individuals, first and foremost.
Previously, in other studies, scientists have shown that the risks of diabetes are significantly increased in people with the owl chronotype, as well as in those taking steroid drugs.