A joint Group Health-University of Washington (UW) study in the New England Journal of Medicine has found that higher blood sugar levels are associated with higher dementia risk, even among people who do not have diabetes. (Continued below video…)
Blood sugar levels averaged over a five-year period were associated with rising risks for developing dementia, in this report about more than 2,000 Group Health patients age 65 and older in the Adult Changes in Thought (ACT) study.
Every Glucose Level Ups the Risk
For example, in people without diabetes, risk for dementia was 18 percent higher for people with an average glucose level of 115 milligrams per deciliter compared to those with an average glucose level of 100 mg/dl. And in people with diabetes, whose blood sugar levels are generally higher, dementia risk was 40 percent higher for people with an average glucose level of 190 mg/dl compared to those with an average glucose level of 160 mg/dl.
“The most interesting finding was that every incrementally higher glucose level was associated with a higher risk of dementia in people who did not have diabetes,” said first author Paul K. Crane, MD, MPH, an associate professor of medicine at the UW School of Medicine, adjunct associate professor of health services at the UW School of Public Health, and affiliate investigator at Group Health Research Institute.
“There was no threshold value for lower glucose values where risk leveled off.”
Very Rich Data
“One major strength of this research is that it is based on the ACT study, a longitudinal cohort study, where we follow people for many years as they lead their lives,” said senior author Eric B. Larson, MD,
MPH, a senior investigator at Group Health Research Institute who also has appointments at the UW Schools of Medicine and Public Health. “We combine information from people’s research visits every other year with data from their visits to Group Health providers whenever they receive care. And this gave us an average of 17 blood sugar measurements per person: very rich data.”
These measurements included blood glucose (some fasting, some not) and glycated hemoglobin (also known as HbA1c). Blood sugar levels rise and fall in peaks and valleys throughout each day, but glycated
hemoglobin doesn’t vary as much over short intervals.
Combining glucose and glycated hemoglobin measures into a composite measure required special statistical techniques, which Drs. Crane and Larson’s co-authors Rod Walker, MS, a biostatistician,
and Rebecca Hubbard, PhD, an associate investigator, both from Group Health Research Institute, had developed. (Dr. Hubbard is also an affiliate assistant professor of biostatistics at the UW School of
Public Health.) These sophisticated statistical models required specialized data on the relationships between glycated hemoglobin and glucose levels, and they used data generated by co-author David M.
Nathan, MD, a professor of medicine at Harvard Medical School and director of the Diabetes Center at Massachusetts General Hospital.
Less Sugar, More Exercise ?
So should people try to eat less sugar — or foods with a lower “glycemic index”? Not necessarily, Dr. Crane said: “Your body turns your food into glucose, so your blood sugar levels depend not only on what
you eat but also on your individual metabolism: how your body handles your food.” But he does suggest that taking walks couldn’t hurt: The ACT study has previously linked physical activity to later onset and
reduced risk of dementia, including Alzheimer’s disease.
Furthermore, Dr. Crane emphasized that these results come from an observational study: “What we found was that people with higher levels of glucose had a higher risk of dementia, on average, than did people
with lower levels of glucose,” he said. “While that is interesting and important, we have no data to suggest that people who make changes to lower their glucose improve their dementia risk. Those data would have to come from future studies with different study designs.”
This study and CBS news story were released 11 years ago in 2013. While I’m sure that those findings are still relevant today, aren’t there any newer studies that confirm or improve on that one? It would be nice if Alz Weekly could share the latest research, too. Thanks! As a dementia family caregiver first for my late father and now for my mother, I always want to know the latest findings. I appreciate this website and newsletter.
Since the body turns all food into sugar, the article should more specifically use the term "blood glucose" instead of just glucose or sugar, as blood glucose is the indicator used. And walking helps push blood glucose into cells and out of blood.
Well said, Motormouth!
The only part that I do not agree with is lowering cholesterol levels. Folks with dementia have low cholesterol. The brain needs cholesterol for protection of brain cells and synaptic interchanges. Approximately 20% of cholesterol is stored in brain, but only 40% gets through the blood-brain barrier. The key fact is this:- You have to distinguish between animal and plant based fats and manufactured fats and spreads. It is not healthy to consume yellow oils and spreads as they cause oxidation and inflammation when heated. No matter if they are sunflower, or canola oil. This is why coconut, flax, almond, extra virgin olive oil are the better solution and a diet low in animal fats. Supplement with fish/krill oil tablets if you cannot get fatty fish in your weekly diet. We cannot afford it. We use coconut to bake, fry, spread and it is great. My hair even got darker! The problem with sugar is that it is added in various forms to pretty much everything, so a natural diet is a lot better. I juice beetroot, apple and carrot for my mom to drink and she loves it. Kombucha, herbal tea like Rooibos. There are always alternatives! You are what you eat. Time for folks to think NUTRITION and not MEDICATION. Blood tests are vital as they give clues to where the problem area is. B12 for instance will show up the gut… Watch out for excess Calcium as it is tied to B12 production, Acetylcholine and cholesterol. It is also involved in a toxic thyroid situation like Hyperparathyroidism and an unbalanced sodium-pump. You should NEVER take Calcium supplements. Raw sessame seeds work just fine.
What do you mean calcium is tied to B 12 production? We need B 12 to process protein. And also you state never to take calcium supplements. Don’t just say things without the reason why and your source