A PET scan shows metabolism of sugar in the human brain.
Brain scientists are offering a new reason to control blood sugar levels: It might help lower your risk of developing Alzheimer's disease.
"There's many reasons to get [blood sugar] under control," says David Holtzman, chairman of neurology at Washington University in St. Louis. "But this is certainly one."
Holtzman moderated a panel Sunday at the Society for Neuroscience meeting in Chicago that featured new research exploring the links between Alzheimer's and diabetes.
"The risk for dementia is elevated about twofold in people who have diabetes or metabolic syndrome (a group of risk factors that often precedes diabetes)," Holtzman says. "But what's not been clear is, what's the connection?"
One possibility involves the way the brain metabolizes sugar, says Liqin Zhao, an associate professor in the school of pharmacy at the University of Kansas.
Zhao wanted to know why people whose bodies produce a protein called ApoE2 are less likely to get Alzheimer's.
Previous research has shown that these people are less likely to develop the sticky plaques in the brain associated with the disease. But Zhao looked at how ApoE2 affects glycolysis, a part of the process that allows brain cells to turn sugar into energy.
Her research found that glycolysis helps brain cells communicate and get rid of toxins associated with Alzheimer's.
So she gave ApoE2 to mice that develop a form of Alzheimer's. And sure enough, Zhao says, the substance not only improved energy production in brain cells but made the cells healthier overall.
"All of this together increased the brain's resilience against Alzheimer's disease," she says.
Another scientist described how mice fed a diet that includes lots of fat and sugar were more likely to develop both diabetes and memory impairment.
The diet caused an increase in dysfunctional brain cells in the mice, says Sami Gabbouj of the Institute of Biomedicine at the University of Eastern Finland. In people, he says, that could "exacerbate" the development of Alzheimer's.
Sleep problems are another common feature of both Alzheimer's and diabetes, says Shannon Macauley, an assistant professor of gerontology and geriatric medicine at Wake Forest School of Medicine.
She presented research showing that in mice, the brain changes associated with Alzheimer's do interfere with sleep. But abnormal levels of blood sugar, both high and low, also "lead to disrupted sleep," she says
That's concerning, she says, because poor sleep is a known risk factor for Alzheimer's. So maintaining normal blood sugar levels in Alzheimer's patients could improve their sleep and might even slow down the disease, she says.
All of this research on animals could eventually help people, Washington University's Holtzman says.
"If we can figure out what diabetes is doing to increase risk, maybe that would lead us to new targets, drug targets or treatment targets," he says