Release your kung fu grip on that salad plate. Maybe a milkshake isn’t as bad as you think – at least not for your brain.
For nearly a decade, researchers have been honing in on a link between diabetes and Alzheimer’s disease. People with diabetes are twice as likely to get the disease. The problem, studies suggest, is impaired insulin function, the hallmark of diabetes.
Insulin dysregulation starves neurons of glucose, their primary energy source. It weakens blood vessels, mucking up delicate brain circulation. Some research implies that normal insulin levels tamp down sticky proteins that clump up in neuron-killing brain lesions. Messed-up insulin levels might break down that safeguard, actually setting the stage for protein buildup.
But a new study that uses tissue from dead brains and images from live ones questions the assumption that diabetes leads to Alzheimer’s.
Two groups were involved in the study, lead by Dr. Madhav Thambisetty of the National Institute on Aging. One consisted of 197 participants enrolled in the Baltimore Longitudinal Study of Aging. While alive, these folks had oral glucose tolerance tests, which measure how the body responds to a sugar blast. When they died, they had a brain autopsy. The second group included 53 living subjects who had the same test, and also an imaging exam showing whether there was any Alzheimer’s pathology in their brain.
Short answer: There were no correlations between any level of impaired insulin function and the presence of amyloid plaques – the protein clumps that destroy brain cells in Alzheimer’s disease. Neither diabetes nor its younger siblings, pre-diabetes or insulin resistance, showed any relation at all to the physical signs of Alzheimer’s.
So should we celebrate this conclusion with a double mocha latte binge? Maybe not. Dr. Thambisetty qualified his findings by saying most of the subjects didn’t experience the years of insulin dysregulation probably needed to cause that kind of damage. Just last week, a neuroscientist found that insulin in the brain seems to impair the way neurons connect to each other. And there’s still that pesky worldwide finding that diabetes doubles your Alzheimer’s risk.
Like most things in life, science sometimes presents conflicting views. But this finding doesn’t change the fact that what’s good for your heart, your lungs, your muscles, your cancer risk, your stroke risk, is also good for your brain.
Exercise, happy plate, no ashtray: Good. Junk food slurping, couch surfing, tobacco smoking: Bad
It seems the ancients had it right: A sound mind arises from a sound body.