|Antioxidants and Aging|
Dr A. Blackett, of the General Infirmary, University of Leeds, has studied the relationship between vitamin E levels and the accumulation of lipofuscin (the fat/protein substance-'age pigment - associated with ageing) in mice Journal of Gerontology (1981 36:529-33)). Half the mice were supplemented with vitamin E and half were not, and it was found that the levels of vitamin E in the tissues of the supplemented animals rose by 400 per cent over the length of the study (two years) and that the supplemented mice had lower levels of lipofuscin throughout their lives. By the time they were 28 months old they had levels which were similar to non supplemented mice aged 23 months. If accumulation of age pigments is an indication of the rate of ageing, then this is clear evidence that the process is slowed by antioxidant supplementation. Unfortunately the study did not show any consistent increase in life span for the supplemented mice despite their ability to stay young longer. One argument against expecting any life extension for supplemented mice is that other factors, such as the content of their overall diet and levels of other antioxidants, were unchanged. Clearly, altering
just one factor, as in this example of supplementing one antioxidant, while having health enhancing benefits, does not necessarily prolong life.
A Japanese experiment involving rats showed that vitamin E deficient diets produced a faster rate of lipofuscin accumulation in cells than a diet with adequate vitamin E. Not only did the deficient animals age faster but when exposed to additional fatty toxins their aortas showed signs of tissue damage. This experiment, therefore, showed what is already widely assumed in human terms, that lipid peroxidation can be directly linked, not only to ageing, but also to the illnesses of ageing such as arterial damage, unless adequate antioxidants such as vitamin E are present (S. Hirai et al, Proceedings of the International Conference of Lipid Peroxides in Biological Medicine, Academic Press, New York, 1982).
A Russian study involving rabbits showed what happened when they were fed a diet deficient in vitamins C and E as well as co-enzyme Q10 (all of these are powerful antioxidants present in a good balanced diet). All the rabbits on the deficient diet showed signs of advanced premature ageing within 50 to 100 days, suggesting (or rather confirming) a major contribution to the ageing process from free radical activity (O. Voskresenskii et al, 'Chronic polyantioxidant insufficiency as a model for ageing' Dokl. Akad. Nauk. USSR (1983) 268:470-3
The activity of the important antioxidant enzyme glutathione peroxidase was found to be extremely poor in duckling tissues where selenium deficiency existed. In these same ducklings supplementation of vitamin E had no effect on improving glutathione peroxidase activity. This Chinese study teaches us several important things, including the strong link between vitamin E and selenium, in which a symbiotic relationship exists, both antioxidants being more powerful in their work when the other is present. However, when one is absent (as is common in parts of China where levels of selenium in the soil are particularly low, leading to a very high incidence of cancer and heart disease) vitamin E on its own cannot make up for selenium deficiency (G. Xu et al, British Journal of Nutrition (1983) 50:437-44).
Doctors Porta, Joun and Nitta of the University of Hawaii at
Manoa, Honolulu, studied the health and life span effects on rats of six different diets containing various types and levels of fats and antioxidants, with no dietary (calorie) restriction involved. The researchers make the very important point that while no overall life extension pattern was observed, whatever the diet, 'the 50 per cent survival time of rats fed on safflower oil with high vitamin E supplementation was significantly longer than in all other groups'. This indicates that this particular group of animals stayed healthy and young longer than other groups who were receiving saturated fats (e.g. coconut oil) and low, or no, vitamin E supplementation (Henkel Corporation, Minnesota, Vitamin E Abstracts (1980) page 61).
But does life span actually increase in animals on antioxidants? In research conducted at Charles University, Czechoslovakia, mice were studied for the effects on life span of a diet rich in sunflower oil (polyunsaturated oil) or on the same diet with vitamin E also being supplemented. Those mice recieving additional vitamin E 'showed a slight prolongation of maximum life span'. Here we see evidence of some extension of life, using just one nutritional alteration, vitamin E supplementation, although the degree of extension of life was regarded as slight (M. Ledvina et al, Experimental Gerontology (1980) 15:67-71).
There can be very little doubt that antioxidants in the diet offer protection from many of the diseases of ageing, as well as from many of the signs of ageing (those which are caused by free radicals at any rate). There is, however, only limited evidence that antioxidants on their own have very much to offer towards actual life extension, although it would be folly to avoid supplementing to some extent as part of a natural life extension approach. Guidelines for their safe use are given in Chapter 14.
The recurrent theme of earlier chapters comes to the fore again, that dietary restriction is the key to the puzzle of natural life extension. Use of dietary restriction achieves antioxidant effects by two extremely important methods. It reduces free activity due to its effect of lowering rates of metabolic activity, and it enhances some of the antioxidant activity vital to life, notably the functional activity of catalase. As will be explained in Chapter 13, there exist other methods which can alter free radical activity, including the controversial method of chelation therapy, in which an artificial amino acid (EDTA) is infused into the system to leach out heavy metals which are thought to play such a large part in triggering free radical activity.
The subject of the next chapter is the connection between the lowering of core (inner body) temperature and reduced metabolic activity and its implications in the quest for increased life span.
Body Temperature and Life Extension
About The Author
A practicing naturopath, osteopath, and acupuncturist in the United Kingdom, with over forty years clinical experience, Chaitow is Editor-in-Chief, of the Journal of Bodywork and Movement Therapies
. He regularly lectures in the United States as well as Europe where he instructs......more