Alzheimer's Glucose Metabolism

The body uses glucose as its main energy source, but the brain uses more than 60 percent of it. The body and the brain use two different sets of chemical processes to metabolize glucose. When the brain is starved of glucose, which can be the case with uncontrolled diabetes, it can become severely impaired and damaged. Medical experts believe problems with cerebral glucose metabolism are among the early warning signals of Alzheimer's disease.

Glucose Metabolism

• Glucose metabolism in the brain requires a complex process in which the sugar is transported into the brain and converted to another substance. It completes a set of chemical reactions and ultimately is oxidized to carbon dioxide and water for the full use of it as energy. When there isn't enough glucose or when there is a problem regulating it in the body, people begin to suffer mild cognitive impairment, such as problems with recall and processing new verbal information. Over time, this condition can worsen to the full set of symptoms seen in Alzheimer's patients.

What Is Alzheimer's?

• Alzheimer's is a neurological disorder marked by severe cognitive decline, and it becomes more severe over time. Sufferers do more than lose memories, they lose brain functioning. Alzheimer's is primarily diagnosed only on death and is marked by the presence of amyloid plaques, or sticky clumps, and neurofibrillary tangles, or twisted passageways, in the brain. In the Alzheimer's brain, glucose metabolism is diminished significantly. Fortunately, PET scans can pick up when the brain is not properly processing glucose, so these scans may be able to diagnose Alzheimer's before death and its very earliest stages, possibly long before one reaches a high-risk age for the disease.

Should You Seek Early Detection?

• If you have had previously uncontrolled diabetes, you may want to ask your physician about being tested for cognitive impairment. Moreover, research suggests that if your mother has Alzheimer's, glucose metabolism may be the precise mechanism by which your risk of the disease increases. In studies, people who had a mother with Alzheimer's had a much faster reduction in the use of glucose in the regions of the brain most affected by Alzheimer's.

More than Low Blood Sugar

• The brain can compensate for temporary periods of low blood sugar, such as when you overwork and don't eat enough. You may get light-headed, but the brain recovers by sending more glucose into the brain with special transporters. It senses when the body's glucose supply is low and creates more of these transporters. In a diabetic brain, this mechanism doesn't work, and in the Alzheimer's brain, it is severely damaged. Part of the solution, therefore, may be controlling one's blood glucose.

How to Maintain Steady Blood Glucose

• Research from Columbia University Medical Center suggests that rising blood sugar levels, a precursor of diabetes, are responsible in part for these lapses in memory, which means preventing diabetes can play a role in mental functioning. Regular exercise to help maintain steady blood sugar levels, even when you don't have diabetes, may be a way to help ward off memory declines with age.