I seem to have picked this book at the exact wrong time when a  pandemic is unleashed upon us. One of the books where the parts are  better than the whole. Dr. David Sinclair is a well respected researcher  in science of aging. He sets out to explain why we age at all. The  first part of this book is rightly poised with compelling science and  results. Somewhere in the middle, Dr. Sinclair decided to tackle ethical  questions related to aging. He argues haphazardly but fails to bring a coherence into them.

The core theme of this book is a theory of aging that Sinclair calls  "The Information Theory of Aging". Sinclair believes that what we see as  age related degradation is just a consequence of losing information  through DNA damage and stress. All the living cells on Earth seems to  have developed protective mechanism to survive when the environment  outside becomes hostile. These are set of genes called "sirtuins" that  promote DNA repair, controls replication and metabolism. As we age, the  information in these genes gets lost by DNA damage and they don't get  activated when they are needed. This causes cells to go haywire or  sterile which manifests in us as aging. A very compelling theory indeed.  Sinclair also believes this information lost is mostly analog, and  there are some "code-correcting" genes that can restore the lost  information thereby reversing aging. We don't exactly know how to find  these correcting mechanisms but if we can find them, we can actually  live forever in theory.

Dr. Sinclair is a living proof of some of  the theories. He is 50 years old but looks like 20. If you want to live  longer right now, here are the things that you can do.

1. Eat less often. Do fasting. Skip meals without malnutrition. Fasting activates sirtuins naturally.
2. Exercise more. Activates sirtuins as the body is stressed.
3. Don't spike your glucose levels.
4. Take NMN. As we age, the NAD+ levels go down, NAD+ is required for  the body to activate these sirtuins. Increasing NMN should bring the  NAD+ levels to optimal levels.

I would have loved if Dr. Sinclair  struck to science because that itself is fascinating. The second half  could be skipped entirely. Recommended read but pick the important  chapters.