Lillian Wilson

Lifespan by David A. Sinclair

Ageing may be a treatable disease, not an inevitable process. Discover the truth about ageing and age-reversing strategies in 'Lifespan.'

“'Lifespan' gives us hope for an extraordinary life. As the brilliant Dr. David Sinclair explains, aging is a disease, and that disease is treatable. This eye-opening book takes you to front lines of incredible breakthroughs. Enjoy this must-read masterpiece!”
 – Peter H. Diamandis, MD, New York Times bestselling author of 'Abundance and Bold'

Why do people age? What is ageing? And what can we do to slow down that ageing process and even reverse it?

If you are intrigued by these questions, you should consider reading the book ‘Lifespan: Why We Age and Why We Don’t Have To’ by David Sinclair. The author claims that ageing is not a default process that happens to everyone but rather a disease: “I believe that aging is a disease. I believe it is treatable. I believe we can treat it within our lifetimes. And in doing so, I believe, everything we know about human health will be fundamentally changed.”

In this review, we will take a closer look at ‘Lifespan’ so you can decide whether it is worth reading or not.

Author’s background

David Sinclair is a highly esteemed professor in the Department of Genetics at Harvard Medical School. He holds the distinguished position of co-director at the Paul F. Glenn Center for the Biology of Aging, where he leads groundbreaking research in various fields related to aging and longevity.

Alongside his dedicated team, Sinclair delves into the intricate workings of chromatin, energy metabolism, mitochondria, learning and memory, neurodegeneration, cancer, and cellular reprogramming. Through his extensive research, David Sinclair has made significant contributions to our understanding of the biology of aging, providing valuable insights into the potential mechanisms for extending human lifespan and promoting healthier aging.

What is the book about?

‘Lifespan: Why We Age and Why We Don’t Have To’ raises two main counterfactual questions: what if ageing is a disease and what if it is treatable.

The author firmly believes that ageing is not just an inevitable part of life but a treatable illness. David Sinclair views ageing as a loss of epigenetic information and cellular damage resulting from the stressors of life on Earth. Factors such as processed foods, air pollution, radiation, and DNA copying contribute to the gradual deterioration of cells and their identity over time.

Sinclair introduces the concept of longevity or sirtuin genes, which are responsible for cell repair and DNA stability. However, when DNA damage occurs, these defence mechanisms are diverted, causing chaos in the epigenetic makeup and leading to the activation of genes associated with diseases like cancer and Alzheimer’s.

The book highlights the possibility of slowing down and even reversing the ageing process by stimulating sirtuins through cellular stress. Sinclair suggests three daily practices to enhance longevity genes: eating less, engaging in regular exercise, and exposing oneself to extreme temperatures. By subjecting the body to controlled stress, survival circuits are activated, promoting the activation of sirtuins as cellular defence troops. These practices offer potential avenues to boost longevity and combat the effects of ageing.

Furthermore, the book discusses the philosophical and ethical implications of extending human lifespan, as well as the history of longevity research. This makes it an engaging and effective read for science communication purposes.

In ‘Lifespan’, David Sinclair emphasises that perceiving aging as a natural process hinders efforts to understand and combat it effectively.

Table of contents

  • Dedication
  • Introduction: A Grandmother’s Prayer
  • Part I: What We Know (The Past)
  • Chapter 1. ‘Viva Primordium’
  • Chapter 2. The Demented Pianist
  • Chapter 3. The Blind Epidemic
  • Part II: What We’re Learning (The Present)
  • Chapter 4. Longevity Now
  • Chapter 5. A Better Pill to Swallow
  • Chapter 6. Big Steps Ahead
  • Chapter 7. The Age of Innovation
  • Part III: Where We’re Going (The Future)
  • Chapter 8. The Shape of Things to Come
  • Chapter 9. A Path Forward Conclusion
  • Acknowledgments
  • Sinclair Disclosure
  • The Scale of Things
  • Cast of Characters
  • Glossary
  • About the Authors
  • Notes
  • Index
  • Copyright

Key takeaways from ‘Lifespan’

1Eat less and fast

David Sinclair highlights that eating less is the first step in treating the disease of ageing. How does this benefit us? When we limit our calorie intake or engage in fasting, it adds stress to our bodies, activating our survival mechanisms and ultimately enhancing our longevity genes. There are various ways to practice fasting or restrict calorie intake. For example, you may try the 16-8 method, where you fast for 16 hours and then have an 8-hour window for eating. Thus, you skip breakfast, have your last meal at 8 p.m., and then enjoy a late lunch. This creates a 16-hour fasting period.

In terms of diet, it is recommended to prioritise the consumption of vegetables and reduce the intake of meat and dairy products. Additionally, it’s advisable to steer clear of processed foods like french fries and doughnuts, as they are considered unhealthy. Opting for organic options whenever possible is another beneficial practice for increasing lifespan.

2Engage in physical exercises

Another effective practice is to increase your physical activity. Exercise serves as a form of stress that you intentionally impose on your body. As a result, you experience heavier breathing and an elevated heart rate. These physical responses contribute to your overall longevity. A specific form of exercise that particularly enhances the longevity genes or sirtuins is high-intensity interval training. There are various ways to engage in this type of exercise, such as sprints or playing high-intensity sports like tennis. Allocating just 15 minutes each day to high-intensity interval training is sufficient. Therefore, incorporating this practice into your routine can significantly boost your longevity.

3Expose yourself to extreme temperatures

“Because as it turns out, exposing your body to less-than-comfortable temperatures is another very effective way to turn on your longevity genes.”

When you move beyond the thermo-neutral zone, which refers to a narrow range of temperatures where your body doesn’t need to exert extra effort to regulate its temperature, a variety of reactions occur. For instance, being in an ice bath, taking a cold shower, or immersing yourself in a cold sea alters your breathing pattern and accelerates your heart rate. These responses are natural indications that your body is under stress.

Due to homeostasis, the body’s inclination to maintain a stable equilibrium, it will strive to adapt to these conditions. Scientific research demonstrates that exposure to cold activates the sirtuins. Therefore, it is beneficial to expose yourself to the cold several times a week or even daily.

Overall rating & strengths and weaknesses, according to readers’ reviews

The book has gotten 4.18 ⭐️ on GoodReads.


  • The book effectively utilises personal stories and anecdotes to engage readers and humanise the individuals involved in scientific research.

  • The writing style is clear, entertaining, and keeps readers engaged throughout the book.

  • The use of analogies and similes aids in explaining complex scientific concepts in an accessible manner.

  • Complex biology is summarised accurately and concisely, making it easier for readers to grasp.

  • The inclusion of engaging personal tidbits and characterisations adds depth and interest to the narrative.


  • The book neglects to address certain factors, such as advanced glycation end products (AGEs) and lysosomal aggregates, which play a significant role in age-related changes and can impact tissue elasticity, inflammation, and essential processes like autophagy.

  • The exclusive emphasis on epigenetic drift may lead to an oversimplified explanation of aging, overlooking important components of the aging process.

Best quotes from ‘Lifespan’

“There isn’t much debate on the downsides of the consumption of animal protein. Study after study has demonstrated that heavily animal-based diets are associated with high cardiovascular mortality and cancer risk.” 
“Youth → broken DNA → genome instability → disruption of DNA packaging and gene regulation (the epigenome) → loss of cell identity → cellular senescence → disease → death.” 
“As a species, we are living much longer than ever. But not much better. Not at all. Over the past century we have gained additional years, but not additional life – not life worth living anyway.”

Final takeaway

‘Lifespan: Why We Age and Why We Don’t Have To’ by David Sinclair offers an optimistic perspective on the treatability of aging as a disease. The book explores the concept of longevity genes, the impact of cellular stress, and provides practical practices to enhance longevity. It is an enjoyable read that effectively explains complex scientific concepts and engages readers through personal anecdotes.

Overall, ‘Lifespan’ is recommended for those interested in understanding and exploring the possibilities of extending the human lifespan and promoting healthier aging.

Where to buy

You may purchase ‘Lifespan’ on Amazon at the best price. It is available in Kindle, audio, paperback and hardcover versions, so you are free to choose the format that suits you best.

Healthypedia FAQ

Yes, the book is written in a clear and accessible manner, making it suitable for readers without a scientific background. David Sinclair effectively explains complex concepts and provides analogies to help readers understand the science of longevity.

Yes, the book provides practical advice for implementing the practices mentioned, such as calorie restriction, high-intensity interval training, and exposure to extreme temperatures. Readers will find specific recommendations and suggestions on how to incorporate these practices into their daily lives.

'Lifespan' would be beneficial for individuals who are interested in understanding the aging process and exploring potential ways to slow down or reverse aging. It appeals to curious minds, whether they have a scientific background or not, as it presents scientific concepts in an engaging and accessible manner. Readers seeking insights into longevity research, ethical considerations, and potential interventions would find the book informative and thought-provoking.

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