Is High Blood Sugar Behind Cognitive Decline?

By | January 26th, 2018

A recent study shows that people with higher blood sugar levels experience a quicker rate of cognitive decline.

The link between diabetes and dementia has been shown to be strong; so strong, in fact, that some doctors think that Alzheimer’s is a form of diabetes. According to Dr. Rachel Whitmer, an epidemiologist at the Kaiser Permanente Northern California Division of Research, people with diabetes have a 75 to 100 percent higher risk of going on to develop Alzheimer’s. Increasingly, scientists are finding evidence that the two diseases are inextricably linked.

But is it diabetes itself that is connected to Alzheimer’s? Or is Alzheimer’s related to the sugar intake that causes Type 2 diabetes? A new longitudinal study that followed 5,189 people over 10 years showed that people with high blood sugar, regardless of whether that made them technically diabetic, had a faster rate of cognitive decline. The higher their blood sugar was, the faster they declined.

Researchers found that elevated levels of the protein HbA1c, which is a measure of overall blood sugar control used in diagnosing diabetes, was linked to poorer cognitive performance and thinking.

The study does more than link cognitive decline to diabetes, said the researchers at Imperial College London and Peking University Clinical Research Institute in Beijing, China. “Our findings show a linear correlation between circulating HbA1c levels and cognitive decline, regardless of diabetic status,” they wrote in the report. “Our findings suggest that interventions that delay diabetes onset, as well as management strategies for blood sugar control, might help alleviate the progression of subsequent cognitive decline over the long-term.”

However, it is still important to note that this was an observational study that draws conclusions from correlations. We know that people with higher blood sugar do worse on memory tests, but we don’t know if that’s why they experience faster cognitive decline.

“One strength of this large study is that it followed people over time to show a faster decline in memory and thinking in those with poorer blood sugar control, but it does not shed any light on the potential mechanisms underlying this decline,” said Dr. David Reynolds, Chief Scientific Officer at Alzheimer’s Research UK.

Just a few months ago, a study found that people whose brains were bad at breaking down glucose, a form of sugar used to fuel the brain, had higher levels of beta-amyloid, the toxic protein associated with Alzheimer’s disease. The study didn’t examine how a diet high in sugar affects glucose breakdown, but study authors hope prescribing lifestyle modifications will come with deeper studies into how sugar intake affects the brain.

This study was published in the journal Diabetologia.

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2 thoughts on “Is High Blood Sugar Behind Cognitive Decline?

  1. Hi, Thanks For Your Top-Notch Article. Actually, Many people can keep their blood glucose in a healthy range without medications (either oral diabetes medications or insulin injections) if they lose weight and keep their weight down, are regularly physically active, and follow a meal plan that helps them keep portion sizes under control and helps them spread the amount of carbohydrate they eat at each meal throughout the day.

  2. Excellent and informative article, thank you.

    My 74-year old husbands early cognitive decline was certainly impacted by his insulin resistance. This is the first “symptom” we discovered and attacked with our excellent Functional Medicine Physician. Once we got his C14 stabilized we began to see improvements in his cognition and memory. We also made many lifestyle and dietary changes and got his vitamins/minerals/hormones optimized. He began a nutrient rich dietary protocol called Ketogenic Protocol (High healthy fats and no dairy, sugar, grains gluten or carbs) and he continues to improve. We increased his exercise to get more oxygen to his brain, tweaked a few other health issues like getting him off of his cholesterol lowering drugs and his high blood pressure medication and on a memory supplement called ACELTH-CH and so on working with his physician at every step of the way.

    It’s been two years of hard work. but worth every effort and dollar spent. His short term memory is 100% returned, his constant confusion is gone, his empathy toward me is back and he is back to work four days per week. His brain fog is gone and his mind is clear and sharp again.

    On addition to his physical and mental improvements, we have our relationship back as well as our marriage. I am grateful to Functional Medicine and our Functional Physician and Functional Neurologist.

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