Book review - Lifespan by David Sinclair, PhD
Aging and longevity are huge topics in the field of science these days. The concept of "healthspan" is becoming a buzz word. It means to not only live long, but live well. David Sinclair is a Harvard Medical School scientist and one of Time's most influential people in the world. He is a world authority on genetics and longevity.
"Our DNA is not our destiny"
"Aging is a disease, and that disease is treatable"
Many scientists today are studying longevity, and showing promising signs that aging can not only be slowed down, but reversed. The key to this is activating certain survival circuit genes. How do you do this? By certain lifestyle factors like intermittent fasting, cold exposure, exercising with the correct intensity, and eating less meat.
As a species, we are living longer, but not better. In other words, we have gained additional years, but not additional life. Science has shown a high probability that every living thing on this planet still carries an ancient survival circuit called M. superstes. This genetic "circuit" from our ancient DNA, found a way to survive by diverting energy to the area of greatest need, fixing what exists when stresses are present.
Today, humans carry contemporary advanced versions of this survival circuit. These are often referred to as "longevity genes" because they show how organisms can extend lifespan. In addition to making life longer, they make it healthier. These longevity genes are called "sirtuins", and are at the forefront of medical research and drug development.
Sirtuins are like the descendants of M. superstes. These genetic enzymes change DNA "packaging", turning genes off and on as needed. This is a critical component involved with another emerging field of research called Epigenetics. This is another extremely popular area of study in the field of wellness and longevity. Epigenetics is the study of the epigenome, referring to heritable traits that aren't transmitted by genetics.
It is the decline of these sirtuins as well as something called an NAD molecule, which is possibly the reason we get sick and old. In stressful times of need, the sirtuins take charge in our bodies, protecting us against age related diseases like heart disease, Alzheimers (which is near and dear to my heart), osteoporosis, and even cancer. In mice studies, activating sirtuins improves DNA repair, boosts memory, increases endurance, and helps keep weight off. This has all been demonstrated and published in prestigious peer reviewed journals.
As he explains throughout the book, the sirtuins, NADs, and other survival circuits like MTOR, AMPK, and something called autophagy all act as defense mechanisms which are activated in times of stress. Some stresses are too large to overcome, but many are manageable. Examples of these stressors are intermittent fasting, low protein diets, and exposure to hot and cold temperatures (hormesis). Often, during these times of "good" stress, the longevity genes go to work and prompt the appropriate bodily system to survive.
This, in essence, is the start of longevity.
Now, of course the science covered in "Lifespan" is all much more complicated, but this is my attempt at reviewing "Lifespan" to the best of my ability. Some of my words were taken right from the book and some were my own, but I believe it's a good synopsis of a pretty "sciencey" book. For more information, check out David Sinclair's website and social media platforms.