Dementia’s Taste for Blood Sugar

Dementia rates were higher in people with long term elevated blood sugar levels

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) People with diabetes can have high levels of blood sugar. If this high blood sugar goes uncontrolled, patients may be at risk for a number of health problems, including mental health issues. But even in people without diabetes, high blood sugar may present some risks.

A recent long-term study followed a group of seniors for several years. The seniors were tested for high blood sugar and signs of dementia (group of symptoms affecting thinking abilities) on multiple occasions.

The results showed that people with high blood sugar were more likely than people with normal blood sugar to develop dementia.

"Talk to your MD about healthy blood sugar levels."

For this study, Paul K. Crane, MD, MPH, an Associate Professor of Medicine at the University of Washington, led a team of researchers to investigate whether blood sugar levels could be a risk factor for developing dementia.

As part of the Adult Changes in Thought study, 2,067 people, 65 and older, were randomly selected to participate in this long-term study. At the start of the study, none of the participants had dementia. Overall, 232 of the participants had diabetes.

The participants were screened for dementia every two years, and had their blood sugar tested at least five times over the course of two years.

High blood sugar occurs when the body doesn't produce enough, or doesn't correctly use, insulin — a hormone that regulates blood sugar levels. When blood sugar levels are consistently high, a person may be diagnosed with diabetes. 

Over a mid-point range of 6.8 years, 524 of the participants developed dementia, 74 of whom had diabetes.

Among the dementia patients, the researchers concluded that 403 of the participants most likely had a type of dementia known as Alzheimer’s disease.

A normal blood sugar level is around 100 mg/dL. Participants with an average blood sugar of 115 mg/dL were 18 percent more likely to develop dementia compared to participants with normal blood sugar levels.

According to the authors, diabetes is a known risk factor for dementia. Among the participants with diabetes, average blood sugar levels of 190 mg/dL increased their risk of developing dementia by 40 percent compared to diabetes patients with average blood sugar levels of 160 mg/dL.

No differences were found between men and women in the study results.

The study authors concluded that long-term high blood sugar levels could increase the risk of developing dementia. They suggested a possible reason for this link could be the influence of high blood sugar on the small blood vessels in the central nervous system.

This study was published in August in The New England Journal of Medicine.

The National Institutes of Health provided funding for this project. The authors declared no conflicts of interest.

Review Date: 
August 15, 2013
Last Updated:
August 23, 2013