PsychDigest

Socially active and not easily stressed people are less likely to develop dementia

A new study shows that people who are socially active and not easily stressed may be less likely to develop dementia. The study involved 506 older people who did not have dementia when first examined. The results show that participants who were not socially active but calm and relaxed had a 50% lower risk of developing dementia compared with people who were isolated and prone to distress. The dementia risk was also 50% lower for people who were outgoing and calm compared to those who were outgoing and prone to distress.

Sources:

American Academy of Neurology (2009, January 20). Socially active and not easily stressed? You may not develop dementia. ScienceDaily. Retrieved March 3, 2009, from http://www.sciencedaily.com/releases/2009/01/090119210328.htm

Blood sugar levels linked to normal cognitive aging

Maintaining blood sugar levels, even in the absence of disease, may be an important strategy for preserving cognitive health.

“Senior moments” are a normal part of aging. Such lapses in memory, according to this new research, could be blamed, at least in part, on rising blood glucose levels as we age. The findings suggest that exercising to improve blood sugar levels could be a way for some people to stave off the normal cognitive decline that comes with age.

Blood glucose levels tend to rise as we grow older, even for people without diabetes.

Although it is widely known that the early stages of Alzheimer’s disease cause damage to the hippocampus—the area of the brain essential for memory and learning—studies have suggested that it is also vulnerable to normal aging. Until now, the underlying causes of age-related hippocampal dysfunction have remained largely unknown.

Previously research has revealed that decreasing brain function in one area of the hippocampus, called the dentate gyrus, is a main contributor of normal decline in memory as we age. In this new study, the researchers mapped out the specific areas of the hippocampus impacted by late-life diseases such as diabetes and stroke.

This research used imaging in both human volunteers and in animal models, and looked at measures that typically change during aging, such as rising blood sugar, body mass index, cholesterol and insulin levels. Decreasing activity in the dentate gyrus correlated only with levels of blood glucose.

The new findings also suggest that one way in which physical exercise could improve memory is via lowering glucose levels. Previous imaging studies in humans and in mice have documented that among all hippocampal sub-regions, physical exercise causes an improvement in dentate gyrus function.

“By improving glucose metabolism, physical exercise also reduces blood glucose. It is therefore possible that the cognitive enhancing effects of physical exercise are mediated, at least in part, by the beneficial effect of lower glucose on the dentate gyrus. Whether with physical exercise, diet or through the development of potential pharmacological interventions, our research suggests that improving glucose metabolism could be a clinically viable approach for improving the cognitive slide that occurs in many of us as we age.”

This study was built upon an extensive, ongoing epidemiological imaging study that evaluated 240 healthy elders.

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Sources:

Columbia University Medical Center (2008, December 30). Researchers link blood sugar to normal cognitive aging. Retrieved February 6, 2009, from http://www.cumc.columbia.edu/news/press_releases/081230_Aging.html

Wu, W., Brickman, A.M., Luchsinger, J., Ferrazzano, P., Pichiule, P., Yoshita, M., Brown, T., DeCarli, C., Barnes, C.A., Mayeux, R., Vannucci, S.J., & Small,S.A. (2008, December). The brain in the age of old: The hippocampal formation is targeted differentially by diseases of late life. Annals of Neurology, 64(6). 698–706. Retrieved February 6, 2009, from Wiley Interscience at http://www3.interscience.wiley.com/journal/121585822/abstract. The full article can be accessed online for $29.95.

Improved blood flow to the brain can help prevent Alzheimer’s

A slow, chronic starvation of the brain as we age appears to be one of the major triggers of a biochemical process that causes some forms of Alzheimer's disease.

A new study from Northwestern University's Feinberg School of Medicine has found that when the brain does not get enough sugar glucose—as might occur when cardiovascular disease restricts blood flow in arteries to the brain—a process is launched that ultimately produces the sticky clumps of protein that appear to be a cause of Alzheimer's.

This finding is significant because it suggests that improving blood flow to the brain might be an effective therapeutic approach to prevent or treat Alzheimer's.

A simple preventive strategy people can follow to improve blood flow to the brain is getting exercise, reducing cholesterol and managing hypertension. For people who already have symptoms, vasodilators, which increase blood flow, may help the delivery of oxygen and glucose to the brain.

“What we are talking about here is a slow, insidious process over many years where people have a low level of cardiovascular disease or atherosclerosis in the brain. It's so mild, they don't even notice it, but it has an effect over time because it's producing a chronic reduction in the blood flow.”—Robert Vassar, professor of cell and molecular biology at the Feinberg School and lead author of the study.

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Sources:

Northwestern University (2008, December 28). Brain starvation as we age appears to trigger Alzheimer's: Improving blood flow to brain is preventive strategy. ScienceDaily. Retrieved February 3, 2009, from http://www.sciencedaily.com/releases/2008/12/081224215704.htm

O’Connor, T., Sadleir, K.R., Maus, E., Velliquette, R.A., Zhao, J., Cole, S.L., Eimer, W.A., Hitt, B., Bembinster, L.A., Lammich, S., Lichtenthaler, S.F., Hébert, S.S., De Strooper, B., Haass, C., Bennett, D.A., & Vassar, R. (2008, December 26). Phosphorylation of the translation initiation factor elF2α increase BACE1 levels and promotes amyloidogenesis. Neuron, 60(6). 988–1009. Retrieved February 3, 2009, from the journal website at http://www.cell.com/neuron/abstract/S0896-6273(08)00947-1. The full article can be accessed online for $31.50.

Major breakthrough in treatment of Alzheimer's announced

A major breakthrough in the treatment of Alzheimer's disease has been revealed by scientists at the Alzheimer's Association International Conference on Alzheimer's Disease (ICAD 2008) in Chicago, Illinois. Their research points to a new treatment that appears to slow the progress of the disorder by 81% over a year. The product -- remberTM -- is the first drug to act on the tangles discovered by Alois Alzheimer over a century ago.

Link: Media Releases - University of Aberdeen.