This is a book well worth reading (and paying for). The in-depth version came out a few years ago as 'Fantastic Voyage: Live Long Enough to Live Forever' and with Transcend most of the speculation about future technologies (MOST) has been cut out, and the focus instead is on "Bridge One", i.e., getting your frickin' act together TODAY. The themes are fairly obvious (exercise, stop eating crap, don't chug coffee every day), but the greatness is in the many details and specific recommendations (and substitutions for all those terrible foods and habits you enjoy indulging in). I have read all of Ray Kurzweil's books now (except his one on managing Diabetes, since it doesn't exactly concern me) and every one has been enlightening and provocative.
The book is clearly aimed at the middle aged, those who (according to the authors) have the most to gain and who are at the most risk, but even if you're my age (26 years old) you can get a lot of benefit from following this book, especially in the nutrition section. I've found many guys (and girls) my age are fairly active physically and intellectually, but because we haven't really begun to feel the effects of aging yet, diet is of very little interest to us. I have good friends who smoke regularly because: "So what man, I can run 10 miles!" This book makes it clear what is going on subtly, behind the scenes as you pump your body full of toxins and bad food, daily!
Because of this book and Fantastic Voyage, I have (over the last couple of years) become a vegetarian (from being a lifelong, HEAVY carnivore), gone from being a total coffee fiend to drinking about one espresso per day and mostly just green tea, begun to appreciate the value of at least some supplements and vitamins in pill form, and started reading a lot more extensively about future technological developments and the real potential of what we can do and experience if we live healthfully for the next 30-50 years. I originally bought these both for my 60-something father, but he never read them and I did, and I can say not only that I feel better but indeed I feel at 26 to adopt these measures I am WAY ahead of the game.
Get it, read it, consider it - and if you find it makes good sense, follow it.