Getting inside your head
(Wikipedia information and other )
The brain consumes up to 20% of the energy used by the human body,
This is more than any other organ. Brain metabolism normally is completely dependent upon blood glucose as an energy source. Although the human brain represents only 2% of the body weight, it receives 15% of the cardiac output, 20% of total body oxygen consumption, and 25% of total body glucose utilization. Deprivation of glucose, as can happen in hypoglycaemia, can result in brain shutdown, and loss of consciousness. The energy consumption of the brain does not vary greatly over time, but active regions of the cortex consume more energy than inactive regions: this allows functional brain imaging methods (PET and MRI). These are nuclear medicine imaging techniques which produce a three-dimensional image of metabolic activity in the brain.
Many older adults notice a decline in their short term memory
The rate of recall from long term memory also increases. Since the human brain has limited resources, people use their attention to zone in on specific stimuli and block out others. One might expect older adults to do poorly on tasks of sustained attention, which measure the ability to attend to and respond to stimuli for an extended period of time. However, studies suggest that sustained attention increases in early adulthood and then remains relatively stable, at least through the 8th and 9th decades of life. Thus speed of function declines more rapidly than accuracy.
Many diseases affect brain function,
Examples include stroke, Parkinson’s disease, cancer, but the most common problem is senile dementia. Alzheimer’s and senile dementia are different .diseases, but have very similar symptoms, with loss of processing speed, reasoning and short term memory. Dementia is essentially caused by loss of blood circulation in the brain, often due to cardiac disease and/or Type 2 diabetes, while in Alzheimer’s the brain shows a characteristic accumulation of amyloid proteins, and these clog the vessels. Dementia is amenable to life style changes, while the treatment of Alzheimer’s requires prevention and deletion of plaques.
Aging of the brain, as with the whole of the body, is inevitable.
However the process can be slowed. In preserving cognitive function, early intervention is vital: when signs of dementia are present, changes in brain physiology have been going on for years. Recent studies show that dementia starts at 40-50 years of age (Glorioso and Sibille 2011)
Action is as effective as thinking!
Exposure to an enriched environment, including opportunities for physical activity, learning and social interaction, may produce structural and functional changes in the brain and influence the rate of neurogenesis in adults. Interestingly, many of these changes can be affected merely by introducing a physical exercise regimen rather than requiring more vigorous cognitive activity.
Heart disease and adult onset diabetes are both closely linked to the early onset of dementia and both of these chronic diseases cause decreased blood circulation to the brain. Both also respond well to lifestyle changes.
Maintaining good circulation is the key to keeping brain cells alive, so any lifestyle changes that preserve cardiac function (weight loss, lowering LDL cholesterol and triglycerides, giving up smoking and, of course, exercise) can protect against dementia.
Corder, R., W. Mullen, et al. (2006). ""Oenology: Red wine procyanidins and vascular health"." Nature 444 566.
Glorioso, C. and E. Sibille (2011). "Between destiny and disease: genetics and molecular pathways of human central nervous system aging." Prog Neurobiol 93(2): 165-181.
Kaplan, R. J., C. E. Greenwood, et al. (2000). "Cognitive performance is associated with glucose regulation in healthy elderly persons and can be enhanced with glucose and dietary carbohydrates." Am J Clin Nutr 72(3): 825-836.
Kennedy, D. O., A. B. Scholey, et al. (2002). "Modulation of cognition and mood following administration of single doses of Ginkgo biloba, ginseng, and a ginkgo/ginseng combination to healthy young adults." Physiol Behav 75(5): 739-751.
Morgan, A. and J. Stevens (2010). "Does Bacopa monnieri improve memory performance in older persons? Results of a randomized, placebo-controlled, double-blind trial." J Altern Complement Med 16(7): 753-759.
Shi, J., J. Yu, et al. (2003). "Polyphenolics in Grape SeedsBiochemistry and Functionality"." Journal of Medicinal Food 6(4): 291–299.