Blood Sugar Levels May Be Critical to Preventing Memory Loss
Click here to read Brian's column "Gerotalk" on the ADVANCE for Long-Term Care Management Web site.
In the May 2009 edition of Scientific American Mind, a short article is provided on the research conducted by Scott Small at Columbia University. The article entitled, An End to Senior Moments: Lowing blood sugar levels may thwart forgetfulness, addresses the impact that higher blood glucose levels may have on proper brain function. The article also may help explain why exercise is a powerful component to healthy aging, including a healthy brain.(1)
It has been known for some time that as we age there is an increased likelihood for blood glucose levels to increase. Although the brain is a glucose hungry organ, consuming 20 percent of the glucose needs of the body, too much excessive blood sugar can be potentially problematic for the body and the brain. It appears that as we age the cellular membrane becomes less sensitive to insulin, which in turn prevents this important sugar from properly moving into the cells for energy and subsequently leading to elevated levels in the older adult's body. When this happens many older adults are susceptible to Type II diabetes.
Levels of blood sugar have been tied to potentially reversible memory issues at all stages of life. Those that suffer from hypoglycemic or hyperglycemic reactions often report problems with their levels of consciousness as well as with memory. The brain, although very dependent on glucose for its function, needs to strike a balance between not flooding itself with excessive levels of glucose as well as failing to not take in too little glucose. Yet, the brain is a very resilient organ that can often recover from excesses in either direction.
In the recent study completed by Small, he found that as we age the probability for increased blood sugar levels affecting memory can be considerable, and can help explain many of those periods of forgetfulness or less efficient functioning of memory that many individuals experience, and complain about, as they age. In fact, many of these factors that are related to less efficient metabolism of glucose start to happen fairly early in life-in our late 30s and early 40s. This becomes quite interesting. One hypothesis that this leads to is what are the cumulative effects on the brain of uncontrolled blood sugar levels, and do those that have less control over their blood sugar levels become more prone toward dementia as they age due to the cumulative insults on the brain of unchecked blood sugar levels.
Small's study goes further in targeting the part of the brain that the higher blood sugar levels may disrupt, leading to memory problems. Although the hippocampus is known for being an important part of the brain for memory, a particular part of the hippocampal area known as the dentate gyrus appears to be particularly sensitive to higher glucose levels. According to Small's research this area, when inundated with excessive levels of glucose, appears to lead to problematic forgetfulness.
This new research could have very important implications for the need to continue to remain active as one ages. As stated, issues of glucose metabolism start fairly early in life, in ones third and fourth decades of life. Although the current research did not answer any questions on the cumulative effect of unchecked blood sugar levels on the brain, it does lead one to make hypothetical assumptions that need to be answered through future research. However, more important to the current research is the continued support it provides for the need for regular exercise.
Small extrapolates from his current study that exercise may be potentially a very powerful tool for warding off many of the common age-related memory declines that are found among individuals as they age. In fact, due to the potential increase in blood sugar levels starting relatively early in life, the need for regular exercise may actually be more important as we age. Especially as it relates to brain health, as our normal metabolic processes decline with age, exercise can actually enhance the movement of glucose into cells and help reduce the excessive blood sugar levels that may lead to age related memory problems. This is actually very good news since many of the transient memory problems that plague us as we age can be reversed through exercise, leading to greater memory efficiency.
The article in itself does not provide a great epiphany. It has been known for some time that sugar metabolism can dramatically effect memory. Moreover, it has been known that exercise is an important source for warding off illness as we age. More recently, exercise has also been associated with helping to improve cognitive functioning and possibly enhancing neurogenesis.
However, Small's study helps to illuminate and provide some sound, empirical understanding of how glucose metabolism may be implicated in the aging brain. It also addresses the specific area in the brain that inadequate blood-glucose metabolism targets and disrupts, leading to many age related memory issues, and this new finding may aid us in advancing brain health for the elderly. Although many know about the positive benefits of exercise on the body, especially for enhancing cardiovascular, pulmonary, and muscular strength and functioning, less often is exercise associated with the positive benefits it has on brain functioning. The implications that it has for getting more individuals involved in regular exercise are very important.
Since cells become less sensitive toward moving glucose into the intracellular apparatus as we age, leading potentially to higher blood-glucose levels, which in turn can lead to excessive glucose targeting brain sensitive areas, and since exercise is an important mechanism for helping to move this biochemical molecule into cells, it is very important to make sure that individuals are getting the proper level of physical activity and exercise to compensate for age related reductions is glucose metabolism. With increased activity we may be able to ward off those so-called "senior moments" that many have come to assume as inevitable parts of the aging process. Therefore, with this knowledge in hand we know that we need to get up, move around, and pay attention to our carbohydrate intake, which in turn may move us into those later years with a more youthful and better functioning memory that is not inevitably consigned to increased levels of forgetfulness.
1. Nikhil Swaminathan (2009). An End to Senior Moments: Lowering blood sugar levels may thwart forgetfulness. Scientific American Mind, 20(2): 9.