Alzheimer’s disease risk has been linked to insulin resistance, according to a new study published in the Journal of the American Medical Association Neurology. The reality that obesity increases the risk of heart disease, Type 2 diabetes, and some cancers is well known, but the Iowa State University study shows memory loss is also a concern.
Insulin resistance is a common occurrence in those who are obese, pre-diabetic, or have Type 2 diabetes. Insulin resistance is a condition in which the cells of the body are unable to use the hormone insulin effectively, leading to high blood sugar levels.
The study analyzed 150 brain scans of late middle-aged adults (average of about 60-years-old). These subjects were at risk for Alzheimer’s disease, but showed no evidence of memory loss. The results showed that subjects with higher levels of insulin resistance use less blood sugar as energy in the areas of the brain that are more vulnerable to Alzheimer’s disease. Because of this, the brain has less energy to transmit information and work properly.
“If you don’t have as much fuel, you’re not going to be as adept at remembering something or doing something,” says Auriel Willete, lead author on the study. “This is important with Alzheimer’s disease, because over the course of the disease there is a progressive decrease in the amount of blood sugar used in certain brain regions. Those regions end up using less and less.”
The study focused specifically on the hippocampus, an important region of the brain that is used for learning new material and sending information to the long-term memory center. This area of the brain is also one of the first areas to show shrinkage due to inactivity as a result of the Alzheimer’s disease.
No other study has made a connection between insulin resistance, Alzheimer’s disease, and the decline of memory. This new discovery is important for the prevention of the disease, but it also shows the importance of taking immediate action. Blood sugar issues can affect the memory at any age, and those who are classified as obese should be tested for insulin resistance and should immediately begin taking steps to fix the issue.
Alzheimer’s disease affects as many as 5 million people in the United States, and more than two-thirds of adults are obese. The Centers for Disease Control and Prevention reports that the number of individuals with the disease doubles every 5 years after age 65. By 2050, the number of individuals with Alzheimer’s disease is expected to triple to approximately 14 million.
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