Showing posts with label age associated cognitive impairment. Show all posts
Showing posts with label age associated cognitive impairment. Show all posts

Friday, September 24, 2010

A Natural Response to Alzheimer's Disease

It was only a few years ago that most believed amyloid plaques and protein tangles could not be removed from the nervous system. We now know better and recent findings have important implications for our cerebral health. Over recent years there have been a number of studies highlighting that in contradiction to another once well established opinion, age associated cognitive impairment is not inevitable and there exist a wide range of strategies to ameliorate cognitive decline with aging. Achieving that goal, and in these days that is a realistic goal, is no easy task. It requires a variety of strategies but the long term pay offs are potentially enormous. This possibility first occurred to me on yet another afternoon when I had the energy of a bamboo deprived panda, I was flicking through TV stations and caught a glimpse of an interview with BF Skinner. He related that at his age, 85, he felt he was still going work but he stressed that throughout his life he had been very careful about his health. There is a very important for those who wish to live long and prosper: if that truly is your goal you had better start living towards that goal before you are 35 years old.

Saturday, October 25, 2008

Brain Aging in Relation to Genes, Diet, and Behavior

Over recent years there has been tremendous progress in our understanding of brain aging and neurodegeneration. Whereas in times past it was presumed that little could be done to forestall the onset of age associated cognitive impairment it is now obvious that there is a welter of strategies we can utilise to markedly slow down the rate of age associated cognitive impairment.

This review article from Mark P. Mattson et. al. is a good starting point for enhancing your understanding of brain aging and the strategies that can help in slowing that trend. Some even claim that one can completely forestall brain aging. I remain very cynical of that possibility but hey it is worth a try so give it a go!

In brief, the following strategies are advisable:

  • Regular light aerobic exercise.
  • Moderate fasting a couple of times a week appears to be beneficial. Caloric Restriction, however, is ill advised as there is some suggestion that over the long term it can damage the brain.
  • A good diet, obviously.
  • Avoiding saturated fats and trans fats. Do not eliminate saturated fat, just reduce it.
  • Maintaining an appropriate balance of omega 3 to omega 6 fats.
  • Regular sleeping patterns.
  • Avoiding excessive stress.
  • Treat depression quickly. Numerous studies now indicate that depression damages the brain and the body. In fact sustained major depression is a significant risk factor for Alzheimers and a minor risk factor for heart disease.
  • Avoid knocks to the head. Even mild brain injury can pave the way for latter dementia.


The abstract:

Mattson, Mark P., Sic L. Chan, and Wenzhen Duan. Modification of Brain Aging and Neurodegenerative Disorders by Genes, Diet, and Behavior. Physiol. Rev. 82: 637-672, 2002; 10.1152/physrev.00004.2002.Multiple molecular, cellular, structural, and functional changes occur in the brain during aging. Neural cells may respond to these changes adaptively, or they may succumb to neurodegenerative cascades that result in disorders such as Alzheimer's and Parkinson's diseases. Multiple mechanisms are employed to maintain the integrity of nerve cell circuits and to facilitate responses to environmental demands and promote recovery of function after injury. The mechanisms include production of neurotrophic factors and cytokines, expression of various cell survival-promoting proteins (e.g., protein chaperones, antioxidant enzymes, Bcl-2 and inhibitor of apoptosis proteins), preservation of genomic integrity by telomerase and DNA repair proteins, and mobilization of neural stem cells to replace damaged neurons and glia. The aging process challenges such neuroprotective and neurorestorative mechanisms. Genetic and environmental factors superimposed upon the aging process can determine whether brain aging is successful or unsuccessful. Mutations in genes that cause inherited forms of Alzheimer's disease (amyloid precursor protein and presenilins), Parkinson's disease (alpha -synuclein and Parkin), and trinucleotide repeat disorders (huntingtin, androgen receptor, ataxin, and others) overwhelm endogenous neuroprotective mechanisms; other genes, such as those encoding apolipoprotein E4, have more subtle effects on brain aging. On the other hand, neuroprotective mechanisms can be bolstered by dietary (caloric restriction and folate and antioxidant supplementation) and behavioral (intellectual and physical activities) modifications. At the cellular and molecular levels, successful brain aging can be facilitated by activating a hormesis response in which neurons increase production of neurotrophic factors and stress proteins. Neural stem cells that reside in the adult brain are also responsive to environmental demands and appear capable of replacing lost or dysfunctional neurons and glial cells, perhaps even in the aging brain. The recent application of modern methods of molecular and cellular biology to the problem of brain aging is revealing a remarkable capacity within brain cells for adaptation to aging and resistance to disease.

Sunday, October 19, 2008

Exercise and Brain Aging

There is now abundant research pointing to the beneficial effects of aerobic exercise on cerebral health. This recent study finds that taking up exercise can improve cognition and cerebral health. There is a striking relationship between cardiovascular and cerebral health. The reason for this is obvious: the brain consumes approximately 20% of our oxygen intake, so maintaining maximal blood supply to the brain is critical. One of the reasons Ginkgo Biloba works is because it reduces platelet activating factor, thereby improving cerebral circulation.

Exercise and do it often. You don't have to run marathons, in fact intense exercise can do more harm than good. Light exercise is okay but it is important to push yourself, just going for a casual walk is good but going for a brisk walk is much better.

Exercise effects on cognitive and neural plasticity in older adults
Kirk Erickson and Arthur F Kramer
British Journal of Sports Medicine (2008).
The abstract:

Older adults frequently experience cognitive deficits accompanied by deterioration of brain tissue and function in a number of cortical and subcortical regions. Because of this common finding and the increasing aging population in many countries throughout the world, there is an increasing interest in assessing the possibility that partaking in or changing certain lifestyles could prevent or reverse cognitive and neural decay in older adults. In this review we critically evaluate and summarize the cross-sectional and longitudinal studies that assess the impact of aerobic exercise and fitness on cognitive performance, brain volume, and brain function in older adults with and without dementia. We argue that six-months of moderate levels of aerobic activity are sufficient to produce significant improvements in cognitive function with the most dramatic effects occurring on measures of executive control. These improvements are accompanied by altered brain activity measures and increases in prefrontal and temporal grey matter volume that translate into a more efficient and effective neural system.