admin Ever since selling his payment processor to eBay for $800 million in 2013, Bryan Johnson has dedicated himself to optimizing his health—a journey that involves spending a couple million dollars to make his 45-year-old self function like a man less than half his age. “(H)e has the heart of a 37-year-old, the skin of a 28-year-old, and the lung capacity and fitness of an 18-year-old,” wrote Bloomberg Businessweek in January. Achieving ideal health involves such measures as eating exactly 2,250 calories a day, ingesting dozens of supplements, tracking nighttime erections, and, at least until recently, swapping plasma with his 17-year-old son. (Or, as the New York Post put it, “Tech tycoon who spends $2 million per year to retain youth uses teen son as ‘blood boy.’” )
Johnson is the most recent poster-child for the pursuit of youth at all costs, but he’s certainly not the only one trying to keep old age at an arm’s length. Moneyed bros, Silicon Valley CEOs, and even average Joes are all trying to look, feel, and be younger, to slow down the aging process in order to live healthier for longer. There are longevity clinics that charge patients $100,000 a year, cocktails of drugs that can “de-age” people, custom backyard “cold plunges,” and even a non-denominational church that worships the notion of perpetual life.
Underneath all anti-aging interventions rests the same basic health factor that people like Johnson are trying to fine-tune: biological age. At its most basic level, it’s the idea that the health of your tissues and organs exists independently of the number of candles on your birthday cake. Put another way, your physiological state is probably younger or older than the chronological number of years you’ve lived on this planet.
“Absolutely, biological age exists,” says Dr. Nir Barzilai, director of the Institute for Aging Research at the Albert Einstein College of Medicine in the Bronx.
Calculating biological age can be done in various ways, and scientists over the last decade have tried to develop different “aging clocks” to determine physiological health. The Mayo Clinic, for example, has an EKG clock that can gauge the biological age of someone’s heart. When Barzilai was 58—he’s almost 68 now—he took the Mayo Clinic’s clock, which told him he actually had the heart of a 54-year-old man.
Epigenetic clocks are currently considered the most accurate way to measure someone’s biological age, as they’re an unbiased look into a person’s cellular functioning. (Think of it like the body’s CarFax report.) Epigenetics refers to gene expression, the first step toward constructing proteins, the building blocks of life. Chemical changes are happening all the time to the DNA code inside our cells in what’s called methylation, a process that turns genes on or off as we age. Sleep, stress, nutrition, exercise, the amount of UV light we get—all this, and more, can lead to epigenetic changes in our cells, and it’s generally thought that the more methylation cells undergo, the less efficient they become. Basically, they start breaking down.
