Your brain is a finely tuned organ. But it’s sensitive to the amount of sugar, or glucose, it receives as fuel. Whether you have type 1 or type 2, both the high blood glucose of uncontrolled diabetes and the low blood glucose that sometimes comes with diabetes treatment can affect your brain.
The Dangers of High Blood Glucose
Some of diabetes’ effects on the brain aren’t obvious right away, especially when they are related to high blood sugar.
“With diabetes, you have an increased risk of damage to blood vessels over time, including damage to the small blood vessels in the brain. This damage affects the brain’s white matter,” says Joseph C. Masdeu, MD, PhD, of the Houston Methodist Neurological Institute.
White matter is the part of the brain where nerves talk to one another. When the nerves in the brain are damaged, you can have changes in thinking called vascular cognitive impairment or vascular dementia.
Vascular cognitive impairment can happen with either type 1 or type 2 diabetes, but there are some differences in risk, says Joel Zonszein, MD, director of the Clinical Diabetes Center at Montefiore Medical Center in New York.
“The longer you have diabetes [in general], the more of a chance there is of developing dementia, but we see much less of it in people with type 1 whose diabetes is well-controlled,” he says.
People with type 2 may face a double-whammy because they tend to have other problems that also can cause blood vessel damage.
“These patients tend to be less metabolically fit overall, with low HDL [“good”] cholesterol, high triglycerides, and high blood pressure, and they are more likely to be obese,” Zonszein says.
Diabetes can combine with these other problems to create inflammation that damages blood vessels, so good diabetes control is all the more important, he says.
“Sometimes people want to try a lot of different things before they go to insulin or other injectable diabetes drugs. The last thing they want is to take shots,” says Zonszein. But it’s important to bring down your blood glucose early in diabetes and not chase it for 5 years.”