Dementia, Cognition

(1) “Sugary Diet May Contribute To Alzheimer’s Disease, Study Says”

“Insulin resistance has been shown to affect the same parts of the brain as Alzheimer’s.”

From Yagana Shah, The Huffington Post, July 29, 2015

• “Researchers looked at 150 middle-aged people with an average age of 60, who were at risk for Alzheimer’s, but did not show memory loss at the start of the study. Brain scans revealed that greater insulin resistance was linked to less sugar in key parts of the brain, often affected by Alzheimer’s.“
• “ “If you don’t have as much fuel, you’re not going to be as adept at remembering something or doing something,” the study’s lead author Auriel Willette, of Iowa State University, said in a statement. “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.” “

“Association of Insulin Resistance With Cerebral Glucose Uptake in Late Middle–Aged Adults at Risk for Alzheimer Disease” LINK to abstract

“Conclusions and Relevance:

• Our results show that insulin resistance, a prevalent and increasingly common condition in developed countries, is associated with significantly lower regional cerebral glucose metabolism, which in turn may predict worse memory performance.
• Midlife may be a critical period for initiating treatments to lower peripheral insulin resistance to maintain neural metabolism and cognitive function.”

 (2) Insulin Resistance and Brain Amyloid

From the same research group as the study above:

“Insulin resistance predicts brain amyloid deposition in late middle-aged adults”

Published May/15 LINK  Alzheimers Dement. 2015 May;11(5):504-510.e1. doi: 10.1016/j.jalz.2014.03.011.

“CONCLUSIONS:
This is the first human study to demonstrate that insulin resistance may contribute to amyloid deposition in brain regions affected by AD.”  (AD = Alzheimer’s Disease)

 (3) “New Alzheimer’s Research Reveals Startling Statistics For Women”

Reported by Leigh Weingus, of The Huffington Post, July 22/15  LINK

• “Previous research has found that by age 65, women have a 1 in 6 chance of developing Alzheimer’s, while men have a 1 in 11 chance.”
• “a large study released in April by Stanford University found that women were more susceptible to a particular genetic variation that increased Alzheimer’s risk. Women who had a copy of the gene variant,ApoE4 were twice as likely to develop the disease, compared to women who didn’t have it. By comparison, men with the variation only saw a marginal increase in Alzheimer’s risk.”

The study was by Katherine Lin of Duke University Medical Center.

 (4) “Alzheimer’s Worsens Twice As Fast in Women, Study Finds”

LINK to article on NBCnews.com, by Maggie Fox, July 21/15

• reports on the study above by Katherine Lin, plus two other studies
• “Dr. Katie Schenning of Oregon Health & Science University and colleagues found that the combination of surgery and anesthesia could affect brain volume and thinking – and that women are more affected by this than men.”
• “It didn’t matter what type of anesthesia it was, Schenning told a news conference. “Women exposed to surgery and anesthesia had a more rapid rate of decline…than men exposed to anesthesia,” she said.”

They found that it was specifically the combination of anesthesia and surgery that showed up in the study as being associated with more rapid rate of decline. This study reports on correlation, not causation.

Further, she reports that:

• “Dr. Michael Weiner of the University of California San Francisco has another piece of the puzzle. His team did PET scans of people’s brains, and found women in general have more of the brain-clogging protein called amyloid that is a hallmark of Alzheimer’s.”
• “Women have more amyloid in the brain than men even when you adjust for other factors,” Weiner told a news conference.”
• “Having the APOE4 gene did not seem to matter for women – they still had more amyloid in their brains, and this effect became much greater once they had Alzheimer’s.”

That is, whether a woman had the APOE4 gene or not, on examination, her brain had more amyloid (that would be on average) than men (on average).

A more detailed discussion of these studies is at Alzheimer’s Association alz.org  LINK