Some of these approaches might seem to be more health enhancing than life span extending, but it is almost impossible to distinguish which is which. It seems, therefore, that there is no good reason for not trying to include all three elements of this approach, and I deal with this in greater detail in the section on strategies.

Antioxidants and life span increase
Durk Pearson and Sandy Shaw (in their book Life Extension) quote the work of Dr Denham Harman, who looked at increasing life span by using artificial antioxidants such as BHT (butylated hydroxy-toluene) a substance frequently used as a food additive to protect against spoilage (commonly by free radical activity). BHT was shown by Dr Harman to increase the life spans of mice, initially in those which normally had a short life span due to the spontaneous development of cancer. Critics of this type of evidence for life extension by use of antioxidants suggest that it is only the prevention of cancer which lengthened' the lives of these animals, which in any case did not exceed the norm for the species. Dr Harman has subsequently also produced evidence of life extension in normally long-lived, non-tumour generating mice, using BHT.

A variety of other experiments on mice, chickens and other creatures hint at life span being extended by use of antioxidant nutrition. For example, a report from the Department of Biochemistry, University of Louisville School of Medicine (Proceedings of Society of Experimental Biology and Medicine (1986 183(1):81-5) by Drs J. Richie, B. Mills and C. Lang showed that the use of a powerful artificial antioxidant nordihydroguaiaretic acid (NDGA) could increase the life spans of insects by between 42 and 64 per cent. NDGA was either added to the medium in which larvae developed or to adult mosquito diets (involving different ages and sexes). Young adults and active larvae were the best responders. The researchers make the point that this evidence is important since it demonstrates life extension without dietary restriction.

Why mosquitoes, and do results such as this mean anything in human terms?
Insects have a short life expectancy, and experiments can be conducted which do not have to be spread over many months or years (even mice experiments on life extension take years). They do have implications for humans since, as has been demonstrated by so many researchers into dietary restriction, the effects are found in ALL species tested to date. If life extension is achieved in mosquitoes using dietary restriction, and if it is also achieved using antioxidant nutrition, we can read into this the implication that it would probably help us as well.

Pearson and Shaw quote numerous studies which support the idea of antioxidant supplementation helping health and longevity, however much of this seems (as in the report on the mosquitoes) to involve synthetic substances. For example, they quote studies by Dr Harman involving mice in which senile changes were prevented by use of synthetic antioxidants such as Santoquin, commonly used as a stabilizer in commercial chicken feed, and found to have an unexpected bonus in that it seems to keep chickens laying longer by slowing their ageing processes. As well as retarding the senile changes, this substance also increased the life spans of the mice by between 30 and 45 per cent - equivalent, Pearson and Shaw tell us, to a human life span of 100 years. What that really amounts to is not life extension (since our true life expectancy is around 120) but a definite improvement on our present average life span.