People with type 2 diabetes may lose verbal fluency and verbal memory more quickly than their peers without the condition, according to a 2019 study in Diabetologia.
Researchers in Australia recruited 705 study participants (ages 55 to 90), about half of whom had type 2 diabetes. Three times throughout the study period, investigators tested thinking, planning, and memory skills and assessed participants’ brain atrophy (brain volume and ventricular volume) using magnetic resonance imaging.
Type 2 diabetes was associated with poorer baseline cognitive function as well as faster decline in certain functions like verbal fluency and memory. In participants without diabetes, verbal fluency increased slightly each year. Investigators noted that accelerated cognitive decline can contribute to a loss of executive function (the ability to manage life tasks), which could lead to cognitive losses and possibly the earlier onset of dementia.
The researchers did not find that brain atrophy explained the relationship between type 2 diabetes and cognitive decline. However, other research has suggested that diabetes may injure tiny blood vessels in the brain, excess blood glucose may be toxic to brain cells, or high levels of circulating insulin may affect beta-amyloid breakdown.
These findings provide one more reason to exercise and maintain a healthy diet and weight, strategies that have been shown to lower the risk of type 2 diabetes.