Amino acid restriction, broken hearts repaired, and "your personal longevity coach"
Welcome to the latest issue of Long Youthspan, the only longevity newsletter that’s fun to read. I’m your host, the Youthspan Hound.
Every day, I dig through the latest longevity-related research and throw out the boring, depressing, or impractical stuff. There’s enough of that in the world, and I don’t want to contribute to it. The good news is — there’s still a lot to write about, and a lot to be excited about. So let’s get going.
PRACTICAL LONGEVITY ADVICE
Human study: Amino-acid restriction for less disease and longer youthspan
A methionine molecule, just waiting to get into your body and blow up your waist. Well, it’s not quite that simple. Read on.
What's the news: Restricting dietary methionine and cysteine is good for health and youthspan.
Why we can believe it: This news comes from a study published several weeks ago, and performed by scientists at Penn State University.
The study looked at 20 real, live, human subjects. Each of those lucky humans went through three phases of diet — a control phase, a phase of low amino-acid restriction, and a phase of high restriction.
The results were that restricting both methionine and cysteine over just 4 weeks:
Lowered body weight and reduced waist circumference
Improved LDL cholesterol and a whole host of other blood markers
Increased body temperature, which is a mark of better metabolic function
In short: Restricting methionine and cysteine, even for just a short while, seemed to bring about a generally healthier profile. If this low-met, low-cys diet could be sustained, it might help people avoid many diseases, and promote real youthspan improvements.
Yeah, but what exactly is this diet? First off, the diet was designed by a nutritionist, and was supervised by medical doctors. It consisted of 2,500 calories per day, 50% of which came as carbohydrate, 35% as fat, and the rest as protein/amino acids.
Of those proteins/amino acids, 20-25% were from natural low-methionine and low-cysteine sources, including fruits, vegetables and refined grains. The rest were from specialized supplements and “amino acid-based medicinal drinks” (specifically, a kind of sorry-looking mix called X-Met X-Cys Maxamaid).
So what specifically can you do now? Don't try to cut out methionine and cysteine from your diet entirely — they are present in most foods, and you need a certain baseline amount to avoid malnutrition.
Also, your Youthspan Hound is wary of ever recommending that you swap out whole-foods for medicinal shakes and protein slurries.
That said, this study is an important data point, on a growing hill of evidence, suggesting that protein restriction, specifically for methionine, can be beneficial for youthspan, both short-term and long-term.
Practically, focusing on eating more fruits and veggies might give you some of the same benefits that this study reported — and it would probably good for you in many other ways. And if you do get your protein from shakes or powders, consider checking the label — and opting for the shakes with less or no methionine and cysteine.
THOSE LUCKY MICE (AND PIGS) DEPT.
Gene therapy breakthrough: Regenerating broken-hearted mice
Don’t worry, little guy. Help is on the way. In fact, you are about to become an indestructible super-mouse.
What's the news: Mice were given a new type of gene therapy, based on genes from zebrafish, that fixed their damaged hearts.
Why we can believe it: This news comes from a recent study, published at the end of 2022, and performed by a team of scientists at Duke University.
Introducing a very resilient old fish: Zebrafish are a type of fish that have a natural talent for repairing their hearts in case of damage. Crucially, zebrafish also have the ability to only use this talent when needed — and not all the time, which would cause tumors.
Introducing a very resilient new mouse: In this study, scientists successfully modified the genome of mice via injectable gene therapy. The gene therapy equipped the mice with same heart-repair ability as zebrafish. The scientists also did something similar in pigs.
The scientists then forced these poor animals to actually have a heart attack. But the the most miraculous thing happened: The animals hearts started a dramatic self-repair process that was not seen in untreated control animals.
Why this is such a big deal: This type of gene therapy could translate to humans. Impressively, it could be administered before or after traumatic heart damage such as heart attacks.
As big as that would be, the promise is still bigger. The same kind of therapy might go beyond hearts to the the repair of other organs, including brains, joints, or even entire limbs.
Of course, we're not there yet. Right now, all we can do is wonder at the power of gene therapy that scientists are unlocking. More of these types of news are coming out with each passing week. There's a real possibility that within our lifetimes, damaged organs will heal themselves with just an injection.
IRREVOCABLY PERSONAL
David Sinclair’s new project
Dr. David Sinclair, who is as close to an A-list celebrity as the longevity world currently has. In 2014, Sinclair was among Time magazine’s 100 most influential people in the world.
Who we are talking about: Dr David Sinclair, a professor of biology at Harvard University, known for his research on aging and longevity. Sinclair is as close to a nation-wide celebrity as you can get in the still-modest longevity science world.
Sinclair studies a promising class of proteins called sirtuins, which regulate cellular function. He has also written a bestselling pop-science book about longevity and aging, Lifespan: Why We Age and Why We Don't Have To.
My personal note to David Sinclair: David, why name your book Lifespan? I think a much more appealing title would have been Youthspan: How to Stay Healthy, Shiny, and Playful for However Long You Choose. But maybe I’m biased. Let's get back to business.
So what's the news? Sinclair consults many biotech companies, and has started several of his own. The most recent news, out only a few days ago, is that Sinclair has started a new company called Tally Health, which has gotten a lot of press, in large part because of Sinclair's prestige.
So now what? Now you know Dr. David Sinclair, in case you didn't know him before. He's one of the smartest and most succesful researchers on longevity, and is worth keeping an eye on. And if you’re curious about Tally Health, read on for this issue's Long Youthspan offer.
A LONG YOUTHSPAN OFFER
“Your personal longevity coach,” or an interesting subscription offer
What it is: Tally Health, David Sinclair’s new longevity startup. Tally sells itself as "your personal longevity coach.” That’s a little vague and fluffy. The reality is that they offer a monthly subscription offer.
What do you get: Tally Health’s subscription has three parts:
An aging test, performed every three months. Swab the inside of your cheek, send the results back to Tally, and they will tell you your biological age, using an epigenetic “aging clock.” The idea is that once you can measure your biological age, you can measure which interventions are slowing down your aging, or even reversing it.
A personalized action plan. Again, Tally’s promise is to be your longevity coach. So they provide a “personalized action plan” of lifestyle and daily habits to slow aging, based on your test results in point 1 above.
A daily longevity mix. A supplement to pop every day, featuring calcium alpha-ketoglutarate, resveratrol, quercetin, fisetin, and spermidine.
The price? A mere trifle! A subscription to Tally Health clocks in at $129/month. That’s not cheap, but if you are interested in the latest longevity technology, it might be an acceptable deal.
Quality supplements are not cheap, and a lot of the supplements on the market have none of the advertised active ingredient. Something similar might be true with biological age tests. People have been reporting drastically different ages across tests — perhaps the tests are just random numbers.
The promise with Tally Health is that, thanks to David Sinclair’s name and involvement, you are getting the top-of-the line, both in the supplement field and for the biological age test. Is that really true? You’ll have to make up your own mind. In case you’re curious:
WHAT WE ARE READING DEPT.
Your Youthspan Hound has two watchwords for writing the Long Youthspan newsletter: practical and inspirational.
The Goodnewsletter is a newsletter written with a similar ethos. Every day, they share stories of progress, inspirational helpers, and reasons to be hopeful. In case you would like to read it yourself, or sign up for free:
DID YOU KNOW DEPT.
New study: Sociable mammals live longer
A bowheaded whale, a rare exception to the rule that sociable mammals live longer than solitary mammals. Bowheaded whales can live up to 200 years or more.
I’ll leave you today with a bit of curious and maybe inspiring longevity news, not just in humans, or dogs — but in a study of 1,000 different animal species.
A recent study, published in Nature, looked at the connection between average lifespan and whether a species is solitary, pair-living, or group-living. The results were clear. All other things being equal, group-living animals tended to live longest.
Does this have any practical implications for humans? I’ll leave you to think about that. I know what I’m going to do right now, and that’s to call my mom. Thanks again for reading, and I’ll talk to you again next Thursday.
- Your Youthspan Hound
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