It is well known that dietary restriction can delay puberty, which is one of the reasons for setting the limit for starting such a programme at age 20 or later. It is also well established
that dietary (calorie) restriction may result in a delay in menopause when early restriction patterns have been adopted. In animals the method leads to a lower degree of fertility but this is rapidly reversed, when full feeding is once more started. This can be compared with a common phenomenon seen in women athletes who stop ovulating and menstruating when their levels of body fat are reduced to below 15 per cent of their total weight. This is also seen to happen with girls suffering anorexia nervosa. According to Weindruch and Walford: 'Dietary restriction might in fact be made to act as a birth control measure, at the same time prolonging the time of the child-bearing age' Anyone who is pregnant or who plans on becoming pregnant should take account of this knowledge and avoid or postpone application of dietary restriction accordingly.
Although it might be imagined that dietary restriction would encourage osteoporosis in women, the reverse is thought to be likely. Studies involving animals and humans (vegetarians, for example) indicate that bone metabolism becomes 'younger' with dietary restriction, and as a consequence calcium levels should be maintained at a better level. Weindruch and Walford nevertheless suggest that bone metabolism be monitored during dietary restriction in postmenopausal women.
Additional benefits of dietary restriction
The health benefits which dietary restriction should produce make it a compelling choice, even if the life extension benefits are not 100 per cent guaranteed. The major health benefit would seem to lie in prevention of age-related disease of all types. Areas where benefits might be anticipated, if such diseases already exist (based on human and animal experience), include cancer, hypertension, diabetes, cardiovascular disease, auto immune diseases (such as rheumatoid arthritis), kidney disease and infertility.
Anyone suffering from any disease should be aware that dietary restriction applied to their condition should be monitored by an expert in nutrition and health.
The conditions listed are not suitable for self-treatment, nor is this in any way recommended.
As we move towards a description of ideal eating patterns for dietary restriction we should remind ourselves of the enormous effort which has been put into uncovering the truths which lie behind the evidence. Credit needs to go to a host of researchers, in particular Drs Weindruch and Walford, whose work has been so extensively referred to in this book.
Among their conclusions are:
The overall probability that dietary restriction will retard human ageing and exert widespread favorable effects on health and function, is as great as the efficacy of many preventative and therapeutic measures which orthodox medicine currently recommends.
In fact much that they advocate, whilst based on rigorous orthodox science, comes very close to the methods long advocated by unorthodox (holistic, complementary, alternative) medicine, especially with regard to the methods employed by naturopathic physicians for a century or more, in terms of modification of diet and fasting techniques.
What these scientists have done, in effect, is to prove that the methods naturopaths use (and which they pioneered in Germany, the USA and UK) are safe and effective. These have always been seen to be preventive when started early in adult life, and to offer hope for chronic (age-related) diseases as described in Chapter 3. What naturopaths did not know was that their methods would hold out the chance of an extension of life itself. If this is true, as all the evidence suggests, then we have for the first time, well tried naturopathic methods, supported by the research of scientists of international repute, which might well result in a true revolution in medical thinking.