Memory loss in old age the price we pay for a large brain & a long life?

September, 2011
  • Chimpanzee brains don’t shrink with age as humans’ do. It may be that cognitive impairment and even dementia are our lot because we work our brains too hard for too long.

Comparison of 99 chimpanzee brains ranging from 10-51 years of age with 87 human brains ranging from 22-88 years of age has revealed that, unlike the humans, chimpanzee brains showed no sign of shrinkage with age. But the answer may be simple: we live much longer. In the wild, chimps rarely live past 45, and although human brains start shrinking as early as 25 (as soon as they reach maturity, basically!), it doesn’t become significant until around 50.

The answer suggests one reason why humans are uniquely vulnerable to Alzheimer’s disease — it’s all down to our combination of large brain and long life. There are other animals that experience some cognitive impairment and brain atrophy as they age, but nothing as extreme as that found in humans (a 10-15% decline in volume over the life-span). (Elephants and whales have the same two attributes as humans — large brains and long lives — but we lack information on how their brains change with age.)

The problem may lie in the fact that our brains use so much more energy than chimps’ (being more than three times larger than theirs) and thus produce a great deal more damaging oxidation. Over a longer life-span, this accumulates until it significantly damages the brain.

If that’s true, it reinforces the value of a diet high in antioxidants.

Reference: 

[2500] Sherwood, C. C., Gordon A. D., Allen J. S., Phillips K. A., Erwin J. M., Hof P. R., et al.
(2011).  Aging of the cerebral cortex differs between humans and chimpanzees.
Proceedings of the National Academy of Sciences. 108(32), 13029 - 13034.

Related News

It’s been suggested before that Down syndrome and Alzheimer's are connected. Similarly, there has been evidence for connections between diabetes and Alzheimer’s, and cardiovascular disease and Alzheimer’s. Now new evidence shows that all of these share a common disease mechanism.

Part of the Women's Health Initiative study looking at the effect of hormone therapy on thinking and memory in postmenopausal women, involving over 1400 women, has found those who had high blood pressure at the start of the study (eight years earlier) had significantly higher amounts of

A three-year study involving 169 people with mild cognitive impairment has found that those who later developed Alzheimer's disease showed 10-30% greater atrophy in two specific locations within the

A study involving 511 older adults (average age 78) has found that 11.6% of those with very mild or mild Alzheimer’s (43% of the participants) had mental lapses, compared to only 2 of the 295 without Alzheimer’s. Those with mental lapses also tended to have more severe Alzheimer’s.

Loss of memory and problems with judgment in dementia patients can cause difficulties in relation to eating and nutrition; these problems in turn can lead to poor quality of life, pressure ulcers and infections.

A European trial involving 225 patients with mild Alzheimer's has found that those who drank Souvenaid (a cocktail of uridine, choline and the omega-3 fatty acid DHA, plus B vitamins, phosopholipids and antioxidants) for 12 weeks were more likely to improve their performance in a delayed verbal

Subjective cognitive impairment (SCI), marked by situations such as when a person recognizes they can't remember a name like they used to or where they recently placed important objects the way they used to, is experienced by between one-quarter and one-half of the population over the age of 65.

A German study involving nearly 4000 older adults (55+) has found that physical activity significantly reduced the risk of developing mild cognitive impairment over a two-year period.

Rodent studies have demonstrated the existence of specialized neurons involved in spatial memory.

Although HIV doesn't directly infect neurons, it appears that once it has crossed the blood-brain barrier, it affects supporting cells that can release immune factors that harm neurons.

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health newsSubscribe to Latest news
Error | About memory

Error

The website encountered an unexpected error. Please try again later.