We're not going to dive into all of these, but let's cover a couple that have been getting some extra attention lately: senescent cells, for example. Turns out, there's a limit to the number of times a cell can reproduce, called the Hayflick limit. When cells reach this limit, they're called senescent. "We used to think, well, they're old and in the way, but they're harmless," says Rountree. "But it turns out, they're releasing harmful signals and inflammation to the body."

Another topic you've likely read about right here on mbg is mitochondrial dysfunction. Think back to high school biology classmitochondria are the powerhouses of our cells, which produce ATP or energy. "When we get older, we tend to lose mitochondria because mitochondria don't have the same kind of repair mechanisms as our DNA," says Rountree. "So over time, we get more tired and we don't have the energy to fuel our cellular mechanisms."

Butand here's where things get a little crazySinclair believes there could be one common driver of all nine of these processes, which he sums up with his information theory of aging. "The theory proposes that all of the causes of aging that people are working onfrom loss of mitochondria to senescent cells to telomere shorteningare manifestations of a very simple principle, which is a loss of epigenetic information in the cell rather than genetic information.Meaning that cells lose their ability to read the right genes at the right time, in the same ways that scratches on a CD would mess up the ability to play a beautiful album," he says. (The epigenome, if you're unfamiliar, essentially tells the genome what to do.)

"What I'm proposing," he says, "is that if we can stop the epigenome from degrading, all of these other things go away." But if Sinclair's new theory is true, it raises the question: How the heck do you prevent these scratches (aka epigenome degradation) so cells continue to read the right genes at the right time, and so you can avoid things like fatigue, frailty, and cancer? And can we "clean up" damage that's already there and essentially turn back the clock?

According to Sinclair, there are sort of two levels to that answer. One, there seems to be quite a bit we can do that may effectively slow the aging process (i.e., prevent these scratches) via targeted dietary and lifestyle changes and a few promising supplements, which we'll dive into in the section below.* As for the second part of the question, to truly turn back the clock, lifestyle changes won't cut it. But future therapies and drugs could make that possible.

"We think we've figured out how to reset the age of cells," says Sinclair. "We've figured out that there's essentially a backup hard drive with this epigenetic information that we can access and tell the cells to be young again and reset their clock." Sinclair admits that this work is still quite preliminary, but they've just had some very promising results in animal studies with gene therapy treatments (right now they're injections, but they could eventually be pills). In a study from July 2019, they were able to reprogram damaged optic nerve cells in mice with glaucoma and restore vision.

"That's another level of science that's coming, and we're still in the early stages, but if we can restore vision, what else might we be able to reset?" he asks. Which, to be honest, is equal parts freaky and fascinating.

More:
The New Science Of Aging: How To Biohack Your Way To A Longer, Healthier Life - mindbodygreen.com