True Age by Morgan Levine: Detailed Book Review


My Detailed Review of True Age by Morgan Levine

I first came across Dr Morgan Levine in an interview with Dr Rhonda Patrick and could not wait to review her book True Age: Cutting Edge Research to Help Turn Back the Clock.

This book is the most sensible, pragmatic look at longevity science I have read so far. It is a welcome bridge between the hard science and pop science of other longevity books. My rating is 60% hard, 40% pop.

While others speculate about rewinding the ageing clock, Levine cautions that the complexity of biology means that we are currently a long way from a miracle cure.

It is an optimistic book. True Age is packed with practical advice covering diet choices, exercise, lifestyle options and future avenues of drug research.

This review of Age Later is broken into my five biggest take-away points. It changed my thinking on two important topics in longevity science – obesity and Ageotypes.

About Morgan Levine

Morgan Levine is at the cutting edge of ageing research.

She founded the Laboratory of Ageing in Living Systems at Yale, where she is associate professor. Morgan is also principal investigator at Altos Labs, the moon-shot biotech company, which is part of Alphabet, Google’s parent company.

Morgan Levine

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5 Take Aways from True Age: Cutting Edge Research to Turn Back the Clock

#1 – What Do Methylation Clocks Really Measure?

Morgan Levine starts with a deep dive into DNA methylation clocks.

These clocks, pioneered by Steve Horvath, measure mutations on your DNA. The results correlate with chronological age. Depending on the accuracy of specific measurement, they are used to assess your ‘biological age’ by comparing the average amount of methylation with population averages.

The first problem with them is that they often give different results, even from the same DNA samples. Solutions to this, and the development of more accurate tests is something Levine has been involved in both as a researcher and commercially.

A bigger question is what your ‘DNA methylation age’ really measures – in terms of long-term health outcomes and your ultimate death.

As clinical trials that followed people to old age would take far too long to be useful – the quest for an accurate biological clock is vital. This will unlock clinical data that might otherwise have taken decades.

#2 – True Age Review: Calorie Restriction and Fasting Diets

I detected a subtle rise in the ‘enthusiasm level’ of the writing style when plant-based diets were discussed.

After some research, I found that Morgan Levine is 95% plant-based, and 5% oily fish. Personal preferences aside, the data presented on plant-based eating is compelling. Calorie restriction is a powerful trigger for autophagy – the breakdown of old cells and reuse of their components.

Fasting, both daily (time restricted feeding) and for longer 1 or 2-day periods is highlighted by every longevity scientist I have covered. If you need any more convincing, then True Age covers the science in a pragmatic way – including drawbacks.

True Age Review book Cover

#3 – True Age and Excess Adipose Tissue

I already knew that excess fat accelerates the processes which cause ageing.

What True Age taught me is that the natural balance point in terms of stored fat, varies significantly between individuals. For someone that wants to get back to an equilibrium 10 pounds above their ‘ideal BMI’, the hunger of fasting may simply be too much to handle.

Fat causes inflammation, cell senescence and hinders optimal exercise.

Getting rid of it should be a priority, and obese people will (on average) have shorter and more diseased lives.

That said, I’m more sympathetic to those individual differences after reading the science presented in True Age.

#4 – The Concept of Ageotypes

Little beats something that is obvious as soon as you read it, though you never thought of before.

The concept of Ageotypes is a perfect example. Measuring ageing, reversing our epigenic age and ageing markers assume that we all age in the same way.

But why would we?

Our genes, healthy history and environment are all different (as are our current behaviour and attitudes towards health). True Age introduces some work started at Stanford in 2020, which investigated whether there are broad categories of ‘Ageotypes’ – people that age in distinctive ways.

This adds a level pf granularity to clinical trials for longevity drugs. At this point, we don’t know whether a certain drug or treatment could have positive effects on someone in one Ageotype category, and negligible effects on another.

Older couple

#5 – Drugs are Showing Promise (But Hold Your Excitement for a While)

Levine waited until the end of True Age to cover promising longevity drugs – and for a good reason.

Our current health outcomes are massively influenced by diet, fat reduction, sleep, and exercise. There are hugely promising avenues of drug research – though no magic pills.

The drugs section of True Age covered Rapamycin, Senolytics, Yamanaka Factors and Young Blood. Morgan described the mechanisms, trials and challenges that need to be overcome before these drugs are ready for the mainstream.

Wrapping Up: True Age is a Brilliant Book – Without the Live-Forever Hype

Overall, a brilliant book. While it felt a little middle-class California in spots – it was easy to read and engaging.

It stuck a unique balance between introducing hard science and keeping things simple for new readers.

I enjoyed the sober assessment of longevity science. It is easy to get sucked into the hype that miracles are about to happen. Anyone damaging their health in the hope that a cure will come soon should read True Age.

Sorting out your food, exercise and sleep now will give you the best shot at being around in the 2030’s and beyond – when one or more of the active lines of research declares safe and effective ageing treatments.

As always, no commercial links here to keep my reviews honest. You can find True Age at amazon. And you can find more about Morgan Levine on her lab website here:


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