This is my free weekly newsletter covering 5 interesting points from the week. Subscribe if you’d like to get it in your inbox each week!
1. Lifestyle boosts testosterone, supplements don’t (for Jeff Tang)
I came across this cool post by Jeff Tang explaining that based on 20 testosterone tests done over 4 months, what enhanced his testosterone the most was moving from San Francisco to Costa Rica. He surmised that more sun, less stress and being around more hot people took him from 815 to 1096.
He also noted that Tongkat Ali, Maca Root, Shilajit, Fadogia Agretis, Cistanche, Ashwagandha, and Boron didn’t really do anything for him.
2. The Real Testosterone Booster: Social Dynamics?
"What would raise your testosterone more? Supplements and exercise or beating your boss at some sort of sales competition and getting a promotion and a raise?"
This is a question I pose in a 2020 video about just how important social dynamics are to testosterone levels.
I lay out how the research suggests that testosterone is tightly linked to someone’s perceived standing in a social hierarchy. When someone ‘wins’ at anything from chess to boxing, their testosterone increases. When someone perceive themselves to be a man of high prestige, their testosterone is higher, et cetera. Further, when people have high testosterone, they are likely to engage in behaviors that increase testosterone (if they are successful). The point was that while various lifestyle changes like getting sun, eating healthier foods and doing the right physical exercises are essential, people who are concerned about T should also analyze whether they are sufficiently engaging in the real world and putting effort into activities that (should they be successful) will make them feel like a ‘winner.’
A study based around a rigged rowing contest found that “overall, men who thought they were winners had testosterone levels 14.46% higher their deflated opponents,” commenting that “we found that a perceived shift in social status can cause male physiology to adapt.”
One thing I didn’t spend too much time on in the video was interacting with women. There are several studies showing interacting with women raises mens’ testosterone. A 2007 study begins by saying “It is well-established that males of many nonhuman vertebrate species exhibit hormonal reactions to stimuli from potential mates,” and the result of their experiment was that:
“Men who interacted with women exhibited significant elevations of testosterone relative to both their own baseline concentrations and to change scores among the men who interacted with other men.”
A 2008 randomized controlled trial found that a 5 minute interaction with a woman increased testosterone levels in men. Another study found that men had higher testosterone in the presence of women. They were also more willing to perform risky skateboard tricks, scientifically proving the memes about putting more plates on the bar when big booty women walk into the gym.
3. New Study finds cholesterol to be protective?
A 2023 study titled Dyslipidemia paradox: Analysis from the veterans exercise testing study found that "higher TC [total cholesterol] and LDL-C levels were paradoxically and independently associated with lower risk of all-cause mortality and better survival in men."
The bars in this image are suggesting that as low-density lipoprotein-cholesterol and total cholesterol increases, risk of dying decreases.
4. The ‘Fountain of Youth’ pill Resveratrol is likely junk
David Sinclair was featured on the news program 60 minutes in 2009 talking about the longevity benefits of a compound in red wine - resveratrol. He explains on the Joe Rogan podcast that chemicals like resveratrol ‘turn on our defenses against disease to survive’ and that in 2003 when mice were treated with (the human equivalent of) 250mg of resveratrol, they were immune to the effects of a high fat diet. Basically it mimicked the effects of caloric restriction or fasting without actually having to be hungry. They also claimed to have identified the pathway (sirtuin over-expression) by which resveratrol worked.
Based on the excitement generated by this early research on resveratrol, David Sinclair founded a company called Sirtris Pharmaceuticals which was purchased by GlaxoSmithKline for $720 million.
"Resveratrol has been touted as an antiaging therapy since 2003, when David Sinclair, a Harvard Medical School pathologist and co-author of the current study, found that the life span of yeast could be extended by up to 60 percent when treated with the molecule. The same effect has been replicated in worms, flies and fish. -Scientific American, 2006
However, Dr. Brad Stanfield made a fantastic video digging into the science of resveratrol, debating whether it’s actually worth it for humans to take a resveratrol supplement.
・First, a 2011 paper seemed to debunk the mechanism (sirtuin over-expression) by which resveratrol worked. Meaning that if resveratrol did work, researchers didn’t actually know why.
・The guy who first showed in 1999 you can over-express sirtuins to increase lifespan in yeast, Matt Kaeberlein, said himself on Peter Attia’s podcast that this effect doesn’t necessarily pan out to other organisms.
・Some of Matt Kaeberlein’s own experiments showed that resveratrol does not extend lifespan.
"Nobody to my knowledge has ever been able to replicate to replicate that initial study from the Sinclair lab where they claimed lifespan extension from resveratrol." -Matt Kaeberlein
・Way back in 2009, a study found that it wasn’t resveratrol that was activating sirtuin, but merely a fluorescent dye used in the experiment. So basically the lifespan extension effect Sinclair’s lab observed was due to a lab error. In fact, a 2010 study found the exact same thing, concluding that resveratrol does not activate the lifespan extending sirtuin (SIRT1).
Dr. Stanfield says: “It seems the initial hype was nothing more than poorly conducted experiments.”
There’s still more to the story. I recommend checking out Dr. Stanfield’s video for the rest. He gets into what happened with GSK’s $720 million investment, more specifics on the proceeding resveratrol experiments and other experiments showing potential harm from resveratrol and others showing it likely doesn’t do anything.
5. Longevity Researcher David Sinclair 🧐
David Sinclair is also the guy who popularized the idea that we need to restrict protein to live longer by decreasing mTOR activation.
Sinclair is obviously really intelligent and I think he has useful information to share but many of his takes (that advocate for certain lifestyle choices) leave me scratching my head.
(1) As discussed in my previous post Eating less protein won’t make you live longer, this idea that ‘we need to eat less protein to restrict mTOR so we can live longer’ is completely nonsensical when you look at what actually happens in real world aging humans (not organisms in the lab). Reducing mTOR activation in old age will lead to frailty and reduced muscle mass which the data clearly shows is guaranteed to reduce your lifespan. This idea that reducing mTOR to live longer has only been shown in the lab with non-human organisms living in very specific conditions. I wonder if he will clarify his position anytime soon. While he hasn’t made specific protein recommendations for the elderly, depending on how people take on board this idea that ‘less protein means you live longer,’ it can be very harmful.
(2) Unless I missed his updated position, he still seems to be promoting supplementation of resveratrol despite the info we just discussed above in point #4. He’s clearly aware of the criticisms because someone on twitter asked him about the shaky research behind resveratrol as laid out by Dr. Brad Stanfield, and he replied with a dismissive “It’s confusing I know. Misinformation is everywhere. This is helpful,” linking to a 2006 paper. Dr. Stanfield pointed out that many studies have come out since 2006 that indicate resveratrol’s lack of benefit and potential for harm. Sinclair didn’t see that reply or didn’t have the time to respond to Stanfield.
(3) On the Joe Rogan #1349 podcast, he recommends the compound NMN (nicotinamide mononucleotide). While I won’t get into how it works or whether it’s effective or not in this post, despite David Sinclair recommending it as a beneficial compound, his company Metro International Biotech has basically lobbied the FDA to ban NMN from being able to be sold as a supplement. It’s hard to see any motivation for this other than so that Metro International Biotech could market their own proprietary blend of NMN called MIB-626. That is, it’s a great for them financially to lobby the FDA for a ban, but not so great for the consumer if NMN indeed lives up to its hype.
(4) He’s said on the Andrew Huberman podcast that his microbiome is so adapted to his diet that eating meat will make him feel “terrible.”
That just sounds like his diet has left his gut unable to produce sufficient stomach acid and bile acids to digest meat.
(5) On Lex Fridman’s podcast he equates meat (a steak) with fried chicken. He says basically what he said on the Huberman podcast but he says he overate on “a steak” then corrects himself and says he had “fried chicken specifically,” leaving him feeling “terrible.”
I think pretty much anyone from a vegan to a carnivore would say that generally fried foods are not good for you. If you’re unfamiliar with the fact that vegetable oil (the stuff fried food is fried in) is total junk, check out this video of mine. Blaming an upset stomach on meat rather than gut irritating vegetable oils is odd.
(6) He also said on Lex Fridman’s podcast that "The synthesis of everything I've read, I try to eat a diet that's definitely full of leafy greens. Particularly spinach is great because it's got the iron that we need..." despite the absorption of iron from spinach being around 2%.
(7) He also said on the Joe Rogan podcast #1349 that he takes ambien for sleep, a sedative hypnotic, which is really not facilitating the sleep process but rather just helping you be … unconscious. In addition to causing daytime grogginess, Sleep Researcher Matthew Walker argues that Ambien impairs memory and increases the risk of cancer and death.
I just got his book Lifespan, so I’m interested to see how his thoughts on other things pan out.
Thanks for the shoutout. I’m continuing to summarize published research and evidence-based stories on testosterone on my blog https://tparty.org/. My last post was on Semen Retention for increasing T, which I will be replicating with others.
In terms of the supplements not doing anything, it may be just be the brand, as I talked to another person who used the same brand and also didn’t see increases in T. Apparently Amazon supps suck!
I'm much more inclined to believe in someone like Bryan Johnson who is as transparent as it gets over David Sinclair who is trying to sell books/pills/companies. Really nice observation about the vegetable oil rather than the meat itself as a possible cause for an upset stomach. I personally like to use avocado oil to fry food, it's neutral tasting with high-quality fats and has a very high smoke point.
As smart and well credentialed as some of these researchers are, I think they could all read some Nassim Taleb and admit that we don't understand how complex of a system the human body is. They can find all sorts of associations but that does not imply causation. It's very upsetting that even scientists with PhD's will go out of their way to make stuff up to promote/defend their ideas. I think it's human instinct and very difficult to overcome. I was reminded of this tendency just a while ago when my wife texted me one of her vegan friends lamenting that movie theater popcorn is loaded with butter. Then her other vegan friend texted back with "most movie theaters use coconut oil to cook popcorn". Literally just trying to justify their behavior so that it was not inconsistent with their strongly held beliefs rather than admitting they love the taste of butter. These same vegan friends are also eating some of the most heavily processed food and snacking on things loaded with sugar throughout the day to stave off hunger while admitting to having certain nutrient deficiencies. All for the sake of a misguided belief that their behavior is somehow better for the planet (a huge thank you for all the great content you've posted on this topic).
The world would be so much better off if people could just be okay with eating whatever tastes good to them instead of thinking they need to prove to others they are correct. I personally have been almost exclusively on animal products for the past few months and feel amazing. Pretty sure you can get all the nutrients the body needs regardless of the source but as Bryan Johnson has said in his videos he eats 70lbs of vegetables per month, which is impractical for most people. Like you mentioned with spinach iron having only a 2% absorption rate, the bioavailability for plant source nutrients is just a lot lower.