The cure for aging may not be sleep

Life expectancy in of top-performing countries has increased by three months every year since the early 1800s. For most of human history, you had roughly a 50-50 chance of living into your twenties, mostly due to death from infectious diseases and accidents. Thanks to medical advances, we have gradually found ways to avoid and treat such causes of death; the end result is perhaps mankind’s greatest achievement ever – we have literally doubled what it means to be human, extending life expectancy from 40 to 80 years. On the other hand, this has allowed one scourge to rise above all others to become the world’s greatest cause of death: aging.

Aging is now responsible for more than two-thirds of the world’s deaths – more than 100,000 people every day. That’s because, counterintuitive as it may sound, the main risk factor for most of the leading killers in the modern world is the aging process itself: cancer, heart disease, dementia, and many other health problems become radically more common as we age. We all know that factors such as smoking, lack of exercise and poor diet can increase the risk of chronic disease, but these are relatively small compared to aging. For example, high blood pressure doubles the risk of heart attack; being 80 rather than 40 increases your risk by ten. As the global population ages, the magnitude of age-related death and suffering will only increase.

But this is not my prediction – besides being depressing, extrapolating a two-century trend a year out is hardly groundbreaking. What is much more exciting is that in 2023 we may see the first drug that targets the very biology of aging.

Scientists now have a good understanding of what causes aging, biologically speaking: the so-called “signs” of the aging process range from damage to our DNA—the instruction manual inside each of our cells—to proteins that misbehave because of changes to their chemical structure. Most excitingly, we now have ideas on how to treat them.

By the end of 2023, one of these ideas will likely be shown to work in humans. One strong contender is “senolytics,” a class of treatments that target old cells — what biologists call senescent cells — that accumulate in our bodies as we age. These cells appear to drive the aging process—from causing cancer to neurodegeneration—and, conversely, removing them appears to slow and perhaps even reverse it.

A 2018 paper showed that in experiments in which mice were given a senolytic cocktail of dasatinib (an anti-cancer drug) and quercetin (a molecule found in colorful fruits and vegetables), they not only lived longer, but were at lower risk of diseases including cancer, were less fragile (they could run farther and faster on the tiny mouse-sized treadmills used in the experiments), and even had thicker, shinier fur than their untreated littermates.

There are more than two dozen companies looking for safe and effective ways to get rid of these senescent cells in humans. The largest is Unity Biotechnology, founded by the Mayo Clinic scientists behind the mouse experiment and with investors including Jeff Bezos, which is testing a range of senolytic drugs against diseases such as macular degeneration (a cause of blindness) and pulmonary fibrosis. There are many approaches being explored, including small proteins that target old cells, vaccines that encourage the immune system to clear them, and even gene therapy from Oisín Biotechnologies, named after an Irish mythological character who travels to Tir na nÓg, the land of eternal youth .

Senolytics aren’t the only contenders, either: others currently being tested in humans include Proclara Biosciences’ GAIM protein, which clears sticky “amyloid” proteins, or Verve Therapeutics’ gene therapy to lower cholesterol by modifying the PCSK9 gene. The first real anti-aging drug will very likely target a specific age-related disease caused by a particular trait, rather than aging in general. But the success of a drug that targets an aspect of aging in clinical trials will allow us to consider this loftier goal in the not too distant future.

In 2023, the early success of these treatments could trigger the biggest revolution in medicine since the discovery of antibiotics. Instead of going to the doctor when we’re sick and treating aging-related problems like cancer and dementia in their late stages when they’re very difficult to treat, we’ll intervene preventively to prevent people from getting sick in the first place—and, if those mice that tear on the treadmill something, we will reduce weakness and other problems that do not always cause a medical diagnosis at the same time.