A characteristic of diabetes, insulin resistance is your body’s failure to respond normally to the hormone insulin. The disease dampers your body’s ability to use insulin to convert blood sugar into energy. Diabetes has links to cognitive decline and dementia.
This recent study monitored 489 older adults for over 20 years. The Israeli research team learned subject’s people with high insulin resistance turned in:
- the poorest cognitive performance
- the lowest scores on memory tests and
- the mental skill known as executive function
Insulin governs multiple brain functions. Problems utilizing insulin contribute to accelerated decline in cognitive skills. This might even encourage the development of Alzheimer’s disease.
These results didn’t just apply to patients with Type 2 diabetes. Even mild or moderate insulin resistance increased the risk for damage to mental skills over time.
At the onset of the study, patients averaged 58 years old and all of them had cardiovascular disease. The data was controlled for actual cases of diabetes (from the beginning of the study or developed during the follow-up period) by excluding them.
Cognitive assessments were performed when patients were 72 years old and again around 5 years later (at 77).
A computerized battery of tests examined these cognitive functions:
- executive function
- visual spatial processing
When cardiovascular risk factors were controlled , the elevated ranges of insulin resistance heightened cognitive decline. The association held up even when researchers excluded people with a history of stroke, dementia or diabetes.
An often-cited theory about insulin resistance is that the telltale high levels of glucose damage blood vessels in the brain, increasing the risk for dementia. A few studies found high insulin levels in the blood create damage in the brain, even if blood sugar levels are in the normal range.
Insulin assists brain cells to form connections. This explains its role in memories formation. Other studies show extremely high concentrations of blood insulin prevent the transportation of insulin to the brain tissue, which results in reduced amounts of the hormone in the brain.
Study results suggest exercise and healthy diet may prevent insulin resistance in the brain. Avoiding stress and getting enough sleep are also beneficial to brain health.
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