Sir

Leonard Hayflick makes some good points about ageing and ageing research in his Millennium Essay (Nature 403, 365; 2000). I agree that “humans, and the pet and zoo animals that we choose to protect, are the only species in which large numbers experience ageing”. There has been much conjecture regarding the functions of post-reproductive life in humans and the lack of post-reproductive life in other primates.

However, I think Hayflick's comments about funding by the US National Institute on Aging for Alzheimer's research are far off the mark. Although it is true that humans have a life-expectancy far beyond that for which our evolutionary history has prepared us, it does not follow that our necessary goal is the extension of our life span even further. Far more important is the goal of enhancing the quality of life within the lifespan we already have.

Even modest advances in delaying the onset of Alzheimer's and other age-related diseases can have a tremendous personal and economic impact. Fundamental research on the biology of ageing is immensely important. There is mutually beneficial interplay between research aimed at eradicating Alzheimer's and that directed at understanding ageing in cells, worms, flies, mice, monkeys, apes and humans. Reducing funding for Alzheimer's research is one of the least satisfactory ways to increase funding for the basic scientific study of ageing.