Customer Reviews

A Means to an End: The Biological Basis of Aging and Death

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Professor Clark writes with elegance and employs a reasoned tone, but he is not always direct, and often expresses ideas in the understandably tentative way of a very exacting scientist. Consequently it is not easy to see that nowhere in this book does he directly say what causes aging and death. Nor does he simply say we don't know. What he does say is there are some persuasive theories, especially the evolutionary model began by Haldane and Medawar and refined by George Williams (pp. 49-50), that are consistent with the data that "may be essentially correct, at least in broad outline." (p. 52). Clark makes it clear that we have senescence effector genes in our cells but he doesn't say how they got there, only that they were "already in place in the earliest eukaryotic organisms such as paramecia and yeast." (p. 57) The reader is left to believe that there is a mechanism that retains them, but what that mechanism might be is unclear.

I am led to believe that senescence is built into our cells and is part of our genetic makeup. We are programmed to grow old and die. Just how is what Professor Clark is exploring here. He concentrates on the cellular level because it is his belief that this is where the mechanisms for senescence can be found. On page 190 he argues that senescence is genetically controlled and not the result of a random breakdown, citing the fact that "maximum lifespan is species-specific." In short, humans live a lot longer than dogs, contrary to what might be expected if senescence were caused by cells getting old and wearing out. He points out on page 48 that "mice and humans, although composed of proteins that are extremely similar at a chemical level, have both average and maximal lifespans differing by a factor of 30 or more."

Clark also covers in some detail such issues as the evolution of senescence, average and maximum lifespan; genetic diseases such as Werner's syndrome, the Hutchinson-Gilford syndrome and others; oxidative stress as a cause of cellular senescence and the use of Vitamin E and other antioxidants; the aging brain and Alzheimer's disease; cancer and the social and economic effect of humans living longer. A chapter is devoted to the phenomenon of increased lifespan through restricted caloric intake.

This is an authoritative and persuasive book, well written and well presented.

Dr. Clark provides a good review of the field but fails, in my opinion, to provide a clear explanation for "The biological basis of aging and death". The theories of the evolutionary biology of aging clearly argue that "aging" cannot be "genetically programmed" or that "We are programmed to grow old and die" as other reviewers have concluded from reading this work. That points out the weakness in this book -- a failure to clearly differentiate between senescence, aging and death. There are two primary theories for why we age -- "the declining force of natural selection" (i.e. it is difficult to optimize a genetic program to produce non-aging organisms) and "antagonistic plieotropy" (i.e. the genetic program is optimized for reproduction at the expense of non-aging longevity). Dr. Clark seems to suggest that the genetic program for senescence is what causes aging and death. In fact the genetic program for senescence is largely an anti-cancer program. It may as a side effect contribute to aging and eventually death but its primary purpose is to prevent cancer. There is a very big difference between saying that aging and death result from an "incomplete" program and saying that aging and death result from a pre-programmed senescence program. One of my primary criticisms is Dr. Clark's pseudo-deathist philosophy. The tone of the book seems to suggest that aging is pre-programmed and cannot be changed. He says, on pg 218, "Will we want to go this far in our search for the fountain of youth? It is unlikely even to be proposed in the lifetime of anyone reading this book, but it is not at all beyond the realm of possibility." (He is speaking of the application of gene therapies to lifespan extension.) I have been proposing such methods for lifespan extension for most of the past decade and have conducted research and founded companies to forward these goals. The human genome is a program. It has bugs in it that result in aging. We can comprehend those bugs and apply patches to fix them allowing the extension of human longevity to the accident-rate limits which will be thousands of years. Individuals who really want to understand aging should read books by people who have studied the field for many years. The best authors, in my opinion, would be Steve Austad, Tom Kirkwood and Caleb Finch. While many of their works may be older than this book, they have a greater depth of understanding of the subtleties of the study of aging that this book fails to discuss.

This is a very clearly written, basic book on aging research that is up-to-date. It covers the history of aging research, with particular emphasis on Hayflick's demonstraction of replicative senesence, and gives a fascinating speculation regarding the origin of the aging process in eukaryotic cells as a consequence of sex. Despite this, I really think this is a non-technical book, as he takes time to explain even the most basic of basics, like how nucleotides make up DNA.

This book embraces a rational and well explained journey in the field of aging. Here I read for the first time strong statements about the programmed nature death, that is present since fertilization. We learn the basic experiments that support Haldane theory about sex and aging and we appreaciate the beatiful connection between replicative senescence and species-specifc mortality. The book is clear and well readible and I strongly recommend it to science and non-science crowd.

Professor Clark has written a book that is detailed and accurate, and at the same time accessible to people untrained in molecular biology. If you are interested in increasing both the quality and the length of your life, read this book.

Easy to read book. After lengthy introduction author concentrates on the research about genes that suppress the cell senescence and control. Discussion about cancer cells where cell division is not checked.
Final chapters discusses the effects of oxidants, obesity, low calorie diet or similar things where eventually a claim comes that beside the gene control everything else does not amount more than %15 in total effect.
So unless we control the genes we will soon or later die.

Dr. Clark has written so beautifully on a topic which is not always clearly explained. In caring for elderly patients and looking at our own health decisions, we can truly benefit from his efforts to give us his years of molecular biology experience in a well-designed format. Thank you Dr. Clark.

Ellen M. O'Donohue RN BSN Kelpgull@aol.com