This is Your Brain on Insulin - Diabetes and Alzheimers

This is Your Brain on Insulin
DiabetesHealth
Feb 10, 2009

Remember that public service advertisement that showed a frying egg and then announced, "This is your brain on drugs"? Well, now American researchers think that insulin might be able to shield that brain from the ravages of Alzheimer's disease.

In fact, some researchers believe that Alzheimer's may be a type of diabetes and are calling it a "third form" or "type 3" (which may lead to a bit of confusion because type 1.5 (Latent Autoimmune Diabetes of Adults or LADA) is sometimes called a third form of diabetes).

In a study published in the Proceedings of the National Academy of Sciences, researchers at Northwestern University said that Avandia (GlaxoSmithKline's version of rosiglitazone), which increases sensitivity to insulin, seemed to enhance insulin's protective effect. William Klein, one of the study authors, said in a Reuters article, "Our results demonstrate that bolstering insulin signaling can protect neurons from harm."

Klein said the findings support the new idea that Alzheimer's is a type of diabetes of the brain. "In type 1 diabetes, your pancreas isn't making insulin. In type 2 diabetes, your tissues are insensitive to insulin because of problems in the insulin receptor. Type 3 is where that insulin receptor problem is localized in the brain," Klein told Reuters.

In some people, this can occur with age, Klein said. "As you get older, some individuals start to have less effective insulin signaling, including in the brain," he said, making the brain more vulnerable to toxins that cause Alzheimer's disease.

Klein and other reseachers have theorized that short strands of the proteins known as ADDLs attack memory-forming brain cells, causing the memory loss that Alzheimer's patients experience. Several studies have found that people with diabetes have a higher risk of getting Alzheimer's than people without diabetes.

Klein found that when nerve cells were treated with insulin, the effects of the ADDLs were blocked. The effect was increased when the researchers added the diabetes drug rosiglitazone, which increases insulin sensitivity.

The researchers were quick to point out that the same things that help people with diabetes control their disease-diet and exercise-also are important in combating Alzheimer's.

Source: Reuters Health

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