Book SummaryAgeless, by Andrew Steele

1-Page Summary1-Page Book Summary of Ageless

Though we don’t like to think about it, we’re all going to get old. But in Ageless, physicist-turned-biologist Andrew Steele contends that aging isn’t as inevitable as it seems. Steele argues that we can treat—and even cure—aging. He explains that with scientific advances that are already being tested, we can change the course of the biological processes that make us less healthy as we get older. He contends that one of the most consequential steps we can take as a society is to invest in science that will make longer, healthier lives possible for future generations.

After earning a Ph.D. in physics at the University of Oxford, Steele determined that aging is the “single most important scientific challenge of our time.” So he shifted to computational biology, a field where researchers use large sets of data to understand the human body as a system. Ageless, published in...

Ageless Summary What Is Aging?

Though we all know on a basic level what “aging” is, scientists often use common terms differently than the general public. In this section, we’ll look at how Steele and other experts define aging. We’ll also explore common myths that prevent laypeople and scientists alike from understanding aging as a process we can modify. Plus, we’ll examine exactly what kind of future Steele foresees if we can intervene in the aging processes that make us less healthy and fit.

How Should We Think About Aging?

Steele uses the word “aging” to refer to the process that causes our health to decline—and our likelihood of getting sick or dying to grow—as we get older. A key insight is that the diseases that kill us occur because of the aging process. Steele explains that age is the most significant risk factor for heart disease, stroke, dementia, and cancer, which we often think of as causes of death. He contends that because aging sets these diseases into motion, aging itself is the cause of approximately two-thirds of deaths globally.

(Shortform note: Scientists haven’t quite agreed on a definition of aging—or on whether there’s a single phenomenon [that the word...

Ageless Summary Aging Is a Consequence of Evolution

Now that we know how scientists think about aging and what it might mean to make humans ageless, more questions arise—perhaps most crucially: Why do we age in the first place?

All of human biology has been shaped by evolution. But if natural selection favors traits that are advantageous, it’s counterintuitive that we evolved to become less healthy as we get older. However, Steele explains that evolution involves tradeoffs. Aging evolved because evolution has favored our health and reproductive ability as young adults at the expense of health and longevity later in life.

One theory about how this tradeoff...

Ageless Summary The Processes That Contribute to Aging—and What Science Is Doing About Them

If evolutionary tradeoffs that occurred tens of thousands of years ago explain why we age, then processes that happen in our bodies every day explain how we age. Steele writes that many biological processes cause the symptoms of aging. To figure out how aging happens—and counteract it—scientists need to understand these processes. In this section, we’ve grouped 10 processes that Steele writes are characteristic of aging into three categories: the accumulation of harmful substances, the degradation of crucial systems, and the deterioration of structures and signals. We’ll also explore the discoveries that Steele writes might shape future treatments.

Aging Process #1: Harmful Substances Accumulate

Steele writes that when substances that should be destroyed or recycled accumulate in your body instead, dysfunctions occur. Two materials that have particularly damaging effects as they build up are senescent cells and malfunctioning proteins.

Senescent Cells Accumulate Throughout the Body

Senescent cells—cells that are damaged or stressed but haven’t died—accumulate as you age. Steele explains that each day, hundreds of millions of cells in your body...

Ageless Summary How Can We Prevent Aging With What We Know Right Now?

We’ve discussed the advances that Steele writes may be able to delay or prevent aging in the future. Though much of that science is still in the research stage, he writes that scientists already have enough evidence to know there are things you can do right now to increase your chances of living a long and healthy life. Much of the advice in this section—like eating a balanced diet or brushing your teeth—won’t sound novel. But Steele points out that we already have evidence that these measures are effective at keeping us fit and healthy as we age.

Quit Smoking and Stop Living a Sedentary Lifestyle

The first change to make is to quit if you currently smoke. Smoking increases your risk of cancer, induces DNA mutations, and causes chronic inflammation linked to cardiovascular disease. Steele explains that while smoking reduces lifespan by 10 years, quitting at age 30 restores life expectancy to normal.

(Shortform note: The consensus is strong: Smoking is one of the most unhealthy habits. While many of us know...

Shortform Exercise: Think About How You’d Like to Age

Ageless is all about the scientific discoveries that might enable anti-aging treatments and therapies in the future. But few of those are available to consumers just yet. Steele notes that in the meantime, your lifestyle choices still matter. They can also be motivated by what you want your future to look like.

First, think about what you want your life to look like as you get older. What are your goals? (Do you want to be running 5Ks with your grandkids cheering you on? Do you envision yourself writing the next great American novel at an age when most people are retired?) Write down how you see yourself aging.