Insulin resistance and high blood insulin levels promote age-related degeneration of the brain, leading to memory loss and dementia according to Robert Krikorian, Ph.D. He’s a professor in the Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati Academic Health Center. He has an article in a recent issue of Current Psychiatry – Online.
Proper insulin signaling in the brain is important for healthy functioning of our brains’ memory centers. This signaling breaks down in the setting of insulin resistance and the associated high insulin levels. Dr. Krikorian makes much of the fact that high insulin levels and insulin resistance are closely tied to obesity. He writes that:
Waist circumference of ≥100 cm (39 inches) is a sensitive, specific, and independent predictor of hyperinsulinemia for men and women and a stronger predictor than body mass index, waist-to-hip ratio, and other measures of body fat.
Dr. Krikorian thinks that dietary approaches to the prevention of dementia are effective yet underutilized. He mentions reduction of insulin levels by restricting calories or a ketogenic diet: they’ve been linked with improved memory in middle-aged and older adults. His theory is also consistent with the commonly seen association of type 2 diabetes with dementia: overweight and obese type 2’s quite often have high insulin levels, at least in the early years.
Dr. K suggests the following measures to prevent dementia and memory loss:
- eliminate high-glycemic foods like processed carbohydrates and sweets
- replace high-glycemic foods with fruits and vegetables (the higher polyphenol intake may help by itself)
- certain polyphenols, such as those found in berries, may be particularly helpful in improving brain metabolic function
- keep your waist size under 39 inches (99 cm), or aim for that if you’re higher and overweight
Nearly all popular versions of the paleo diet would qualify as being low glycemic index.
I must mention that many dementia experts, probably most, are not as confident as Dr. Krikorian that these dietary changes are effective. I think they are, to a degree.
I’ve written before about how blood sugars in the upper normal range are linked to brain degeneration. Dr. Krikorian’s recommendations would tend to keep blood sugar levels in the lower end of the normal range.
Steve Parker, M.D.