Longevity is a curious and important point. Does one want to live to old age. Does one want to die old and alert or become time expired and senile and old.
This question has been highlighted by two reports
One by the WHO who showed that in two districts of Glasgow that the expectation of live differed by 28 years. In the socially deprived area the radio interviewed several local people who just said one had to die sometime and why bother. That a diet of fish and chips was enjoyable. A formidable health problem, how can one help those who do not want help. Whose way of life is so poor that the need to prolong it is not great.
At the same time Vijg and Campis have written a review in Nature on the puzzle f ageing.
Ageing and death are inevitable. When we die depends on so many variables and the upper limit of expectation is not known. Different creatures live for a long time others briefly. At the moment the best expectation is 85 years of age though many parts of the world have no hope of this. Manipulations of single genes can extend life. These genes regulate growth, energy metabolism, nutrition , sensing and reproduction. Life expectation increases when activity of the gene is reduced.
Dietary restriction( not malnutrition ) is a potent extender of life expectation.
Three major pathways are involved the insulin receptor system, the mTOR pathway (mTOR) is a serine/threonine protein kinase that regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, and transcription., and mitochondrial pathways.
Easy then , eat less,
But smoking reduces life expectation by 11 years so no smoking and exercise.
Vijg and Campis 2008 Puzzles, promises and a cure for ageing Nature vol 454 pp 1065-71
- Martin Eastwood