You can slow down aging with zero weird tricks | Dr Morgan Levine

Is science gonna actually cure death? The idea of why we age or can you reverse aging or be immortal has actually been a topic of interest for centuries. I think a lot of people don't realize how much power we actually have over our aging process.

Most people think of age or aging in terms of chronological time. So we all know how many years we've been alive, and we usually measure our aging in terms of months, days, years since we were born. We almost give it a magic number. So you're old when you're 65, or you're old when you can see it in the mirror. And we put a lot of emphasis and importance on this measure, but actually, this isn't the number that counts. Scientists think aging is starting even before birth, and it's really this continuous process that's happening over our entire lives.

The most obvious thing that people associate with aging is changes in their skin, changes in body composition, graying of hair. We experience functional changes: our ability to walk, our balance, vision, hearing. And also changes in our risk of developing different diseases. But in reality, these aren't where aging is actually starting. These are what we would call the emergence or the manifestations of aging.

We really think aging is starting at the molecular and cellular level, and once that reaches a given threshold, that's when we actually can start seeing this in the mirror in our everyday lives. I'm Dr. Morgan Levine. I study the science of aging, and my book is called "True Age."

So if I were to ask someone how old they were, their immediate response is going to be however many candles they blew out in their last birthday. It's the number on their driver's license or their passport. And really what this is, is this is our chronological age. It's just the amount of chronological time you've been alive.

This number doesn't hold that much meaning, except that it happens to be correlated with this concept of biological aging. So unlike chronological age, biological age is a thing that we care about. And what scientists mean by biological age is the degree to which your biology has changed over a given amount of time, and we think these changes are gonna be maladaptive. They're gonna lead to more dysfunction, more decline, and ultimately more disease.

And we can actually see these changes on our faces in terms of skin wrinkling, in our hair with graying. But aging is starting at a molecular level, and over time, this is gonna give rise to all the functional changes and manifestations that we tend to see with aging. Many diseases of aging can actually be attributed to dysfunction and decline in specific organ systems.

So something like diabetes can be thought of as a decline in our metabolic system. Things like Alzheimer's disease are declines and dysfunction in our central nervous system. And another disease of aging called sarcopenia, which is the muscle wasting that we see with aging, can be thought of as declines in our musculoskeletal systems.

People have been saying that we should try and quantify this concept of biological age since the 1980s. So Alex Comfort was the first person that proposed that there was this idea of biological age that could be measured. But it probably wasn't until around 2010, 2012 that people were actually putting forth algorithms that we could show and validate were decent, although maybe not perfect measures of this concept of biological aging.

It's gonna tick forward in a monochromatic fashion versus biological age, we actually think is malleable. We know that aging can be slowed. We see this when comparing across species. Species don't decline all at the same rate. Some of them actually do this at such a slow rate, what we call 'negligible senescence,' that we actually can't observe aging in those systems.

So usually to tell how fast different organisms are aging, we look at their 'survival curve.' Do you see an increased risk of mortality in a population as a function of time? And we think of that as the overall rate at which that type of species is actually aging. And we also can see this in humans. Cl...