The claims made in the book, as you described them, simply don't fit the very extensive biological knowledge that we now have about the ageing process. Holistic approaches can help, but the answer will lie in the science. The most important things are to work on a healthy lifestyle, good diet, exercise, managing stress. Given the pressures that you describe, stress is likely to be quite a problem. But there is good news in that some stress is probably good for us because it provokes the body's maintenance and repair systems to get themselves in gear.
Some people think the mind plays a very important part in keeping the body healthy.
Tom Kirkwood Unquestionably, yes. It can certainly stave off many of the problems that come from allowing oneself to become depressed or discouraged in old age. There is evidence that mental activity helps the brain maintain function.