If you want to fight aging, should you turn to stem cells? Does the idea of stem cells to battle getting old even make any sense? The answer is, “it depends.” It’s a really interesting area conceptually and technically for stem cells.
A theory. There is evidence that things that happen to our endogenous stem cells are linked to aging. In my book Stem Cells: An Insider’s Guide, which I’m hoping to get a new edition out for next year, I even proposed the idea that the number of stem cells in our body acts like a biological clock for aging. Less stem cells = older person (see cartoon from the book by my former student, Taylor Seamount). It’s probably not that simply for each individual, but there is a connection. Certainly reduced populations of our existing stem cells are not likely to be helpful to our tissues as we live over the years and decades.
Sketchy or long-shot stuff. The fact that our stem cell numbers tend to decrease with age does not necessarily mean that stem cell treatments for aging make any sense. In fact, there are a lot of problems with the idea of infusions of stem cells to fight aging. First, most clinics selling this idea simply infuse fat (or amniotic) stem cells into the bloodstream, collect their thousands of dollars from customers, and then wave a magic wand or something.
There’s good evidence that those fat stem cells injected into the bloodstream mostly are gone with hours or days, certainly within weeks. They are filtered out in the lungs (one reason for worrying about pulmonary emboli or blood clots in the lungs as a side effect) or elsewhere. Many probably die from the shock of entering the blood stream or are killed by immune cells. In short, there’s a very limited window of time that such cells could do anything helpful and the idea that during that window they could permanently help counteract aging seems like a snowball’s chance in hell. Maybe bone marrow cells would have a relatively better chance.
To really claim help for aging, you’d have to invoke the idea that whatever stem cells you use can permanently engraft in the body, which then raises the possibility of cancer as a side effect. Alternatively, and some clinics go this route, those pushing their own stem cell treatment for aging notion say that many repeated infusions of stem cells are necessary over years and years. That can add up to a lot of profits even if there’s no science backing it up and can empty out customers’ bank accounts.
Then there’s the young blood for aging idea, which has some connections to “stem cells for aging” mantras. There might be something in young blood that can fight aging, but nobody knows what that is and whether it would work in humans or if it’s just a phenomenon in mice. Still, you can pay thousands or even hundreds of thousands of dollars to be in a “trial” of young blood for old, but I think it’s a waste at this point.
Things with better odds. Okay, so you can see I’m skeptical, but in the longer run there may be ways that stem cell research can help battle aging. There may be molecules that can be anti-aging drugs by targeting stem cells. There might even be ways that stem cells themselves could be the basis for a treatment that counteracts aging. Hopefully someone will figure these things out in coming decades because right now there’s nothing real on the stem cell front for aging.
There is legit clinic trial work being planned and conducted related to the stem cell-aging connection including by AgeX and Longeveron, although as to the latter I don’t the data to date are particularly compelling as I blogged before, particularly pertaining to the flu connection. We’ll see. It’s really important to try to avoid hype related to stem cells for aging as well.
In another way of looking at it, stem cell treatments may increase lifespan not through systemically slowing aging, but rather by keeping us alive via maintaining or replacing the function of one key organ. Often us humans die not because of our body’s overall physiological age, but rather because one vital organ gives out on us. On that front there is real promise via stem cells.
I really hope that some real way of fighting aging is discovered and proven…and it’d be extra meaningful for me if it was via something related to stem cells, but in the meantime we should focus as individuals on concrete things proven to add quantity and quality to life. Small changes in behavior that tie in to heart disease, for instance, may be far more impactful as something to focus on than even some ultimately proven anti-aging drug in the future. Me, Dr. Skeptic, even blogged about 5 potential “stem cell boosts” that are focused on just changing every-day things to be healthier like sleeping a good amount.
If there ever is a focused, stem cell anti-aging treatment in the next 50 years, I’d bet that exercise will always beat it out anyway, but we’ll see. Hopefully I’ll live long enough to see if I’m right.