Sugar Damages Brain Leading To Memory Problems

Sugar Damages Brain Structure And Function

Higher Sugar Levels Result In Poorer Memory


Even In People Without Diabetes or Pre-diabetes!

Higher levels of blood sugar damages brain leading to an increased risk for memory problems, even in people who have blood sugar (glucose) levels within the normal range, a new study suggests.

Previous research has shown the direct link between blood glucose levels and increased risk of coronary artery disease. Now a new study published in the October 23, 2013 online issue of Neurology; the medical journal of the American Academy of Neurology, finds that eating high carbohydrate meals can be hazardous to both brain structure and function.

Glucose Has A Direct Affect On Memory

The study involved 141 people with an average age of 63 who did not have diabetes or pre-diabetes, which is also called impaired glucose tolerance. People who were overweight, drank more than three-and-a-half servings of alcohol per day, and those who had memory and thinking impairment were not included in the study.

The participants’ memory skills were tested, along with their blood glucose (sugar) levels. Participants also had brain scans to measure the size of the hippocampus area of the brain, which plays an important role in memory.

The investigators found that lower performance on 3 memory tasks (delayed recall, learning ability, and consolidation) was associated with higher levels of both the long-term marker of glucose control Hemoglobin A1c (HbA1c) and the short-term glucose marker insulin.

People with lower blood sugar levels were more likely to have better scores on the memory tests. On a test where participants needed to recall a list of 15 words 30 minutes after hearing them, recalling fewer words was associated with higher blood sugar levels. For example, an increase of  7 mmol/mol of HbA1c went along with recalling 2 fewer words. Those people with higher blood sugar level, even though the levels were normal, also exhibited smaller hippocampus size.

According to study co-author Agnes Flöel, a neurologist at Charité, the results “provide further evidence that glucose might directly contribute to hippocampal atrophy,”

“These results suggest that even for people within the normal range of blood sugar, lowering their blood sugar levels could be a promising strategy for preventing memory problems and cognitive decline as they age,” said study author Agnes Flöel, MD

These findings indicate that even in the absence of diabetes or glucose intolerance, higher blood sugar damages brain and disrupts memory function.

How Blood Sugar Damages Brain

Memory performance was correlated with hippocampal volume. Lower levels of HbA1c were associated with larger hippocampal volume.

The hippocampus is particularly vulnerable to disturbances in metabolic supply, including glucose, said Dr. Flöel.

“Elevated blood sugar levels may damage the outer membrane of the cells, or decrease neurotransmitter levels, which would disturb signaling within and between hippocampal cells. Information transfer between cells, which is indispensable for memory encoding, storage and retrieval, would then be compromised.”

Elevated blood sugar damages brain by damaging the small and large blood vessels in the brain, leading to decreased blood and nutrient flow to brain cells or even brain infarcts, and this may further damage memory-relevant brain structures, added Dr. Flöel.

When Sugar Damages Brain This May Lead To Dementia

“There have been some initiatives to put prevention more on the agenda of dementia research,” she said. “There has been so much money spent on treatment of Alzheimer’s disease and it has already been established that this is not very successful. “

Dementia prevention strategies could include taking measures at an earlier stage to encourage physical fitness and control hypertension, and now blood glucose levels to prevent how sugar damages brain.

Patients should have their fibrinogen levels, fasting glucose and HbA1c levels measured as part of a regular health check-up and discuss how sugar damages brain tissue with their doctor.

Viewing Affects Of Glucose On Cognition From A New Perspective

A doctor commenting on these findings said that the study’s finding how sugar damages brain tissue looks at the link between glucose metabolism and cognition with fresh eyes.

“This is saying that immediate learning and A1c levels, and potentially even blood sugars, interact even in people who are non-demented, and I don’t think anyone has looked at it that way before,” said the doctor.

“The idea is that the lower the A1c the better your brain function. This is a very exciting development and clearly helps put a frame around the Alzheimer’s discussion, but more importantly, it talks about how blood sugar metabolism and cognitive function directly interact.”

The study opens “a whole new territory” because until now, HbA1c and blood glucose have been looked at only in the context of diabetes and the risk for diabetes, he added. “Maybe we need to rethink our normalization of glucose with an eye toward cognition and not simply a diabetes risk.”

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