> In this analysis we observed little evidence of age-independent trends with respect to most covariate factors; notable exceptions to this rule, however, were the aforementioned increases in relative weight, as well as population-level changes in the prevalence of smoking and the concurrent use of multiple medications (polypharmacy). There were substantial age-specific increases in obesity and polypharmacy over the course of study follow-up
Obesity is still a huge contributor to reduced testosterone, and this study doesn’t disagree with that. It’s such a well-known effect that it’s one of the first things the authors note and try to account for. These studies are trying to identify factors beyond obesity and reduced physical activity, but it’s difficult to tell if they’ve developed an accurate model to subtract those effects from their study.
While it’s possible that environmental toxins like BPA can contribute to neuroendocrine disruption and should be investigated, lifestyle factors are still at the top of the list of things people can adjust to influence their own testosterone levels.
I do wonder if there is also an issue with reduced testosterone causing weight gain, which in turn lowers testosterone... and so. In a positive feedback loop
As someone else mentioned this is from 2007. And another mentioned the first they thought was BPA.
I'll also add this from the article:
Setting: This was an observational study of randomly selected men residing in greater Boston, Massachusetts.
There hasn't been a slew of studies since from around the US. "American Men" is a huge stretch for such a localized study. It very well could have been one of the studies that alerted to BPA, but it could also be a very localized environmental effect.
Either way, this study should not scare anyone, except in it's overreach.
“ These findings indicate that the past 20 yr have seen substantial age-independent decreases in male serum T concentrations, decreases that do not appear to be the consequence of the contemporaneous trends in health and lifestyle considered here. It remains unclear to what these apparent population-level decreases in T are attributable.”
My first thought was BPA, but it appears the effects of plasticizers on the male endocrine system are mixed[1].
Still can’t help but think this is something environmental and chemical at work.
> Still can’t help but think this is something environmental and chemical at work.
I absolutely agree. I read a meta study where they concluded lab rats have been gaining fat since the 70s - and these rats have well documented genetics, very precisely controlled diets, tons of expertly collected high quality data. It was pretty damning
Please note that "data were restricted to observations obtained on men of age 45–79 yr born between 1916 and 1945" and that this is a longitudinal survey with three sets of sample collection times dating from 1987 to 2004.
Also in the absence of longer-term or non-American data, we don't know if this is a decline from 'normal'. There's a lot of weird chemicals out there nowadays with biological effects, but there were a lot of those in the 20th century too.
What I mean is, maybe instead of 'testosterone levels are low today because of all the soy', it's 'testosterone levels were inflated back then because of leaded gasoline (or DDT or asbestos or ....)'.
In one documentary they said that the contraceptive pill is poisoning the water with “female” hormones. Hundreds of millions of women take it every day and the hormones end up in the drinking water.
Eh, I drink liters of soymilk daily. Most common brands of Soymilk are junk though, ie. Silk. Other brands like Westsoy and 365 sell real soymilk without being watered down, sweetened, and fillered.
If anything, the soyboy superstition probably comes from just drinking sugary beverages and meals that lack sufficient fats and proteins for muscle building. Lack of cholesterol could also be an issue if one's genetics are of a low-production type.
Soy itself is somewhat of a super legume. The only legume that comes close is peanuts. And it's not very common to find peanut milk. Elmhurst used to sell it, it was amazing.
I have no problem building muscle [1] and my last free T test was around 850. Anecdotally, I doubt soymilk is the issue.
This is explained in great detail in Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race by Shanna Swan and Stacey Colino
Dr. Shanna Swab has been on at least one big podcast that I’ve seen. The discussion was fascinating. I won’t name the podcast because people get weird about it here.
A large part might have to do with internet pornography. Masturbation is already known to lower T levels temporarily. Do we know what the long term effects of chronic masturbation are?
Before you prepare to downvote me for having Christian sentiment, know that semen retention is actually an old eastern practice known to boost libido and health.
And yes, (ready for the pedants), prostate health has been correlated to unclogging old fluid in "the pipes" but that doesn't require the frequency of masturbation that is commonly practiced by single men in America.
The mental effects of constant video arousal have already been documented to be the cause of underperformance and erectile dysfunction in men. It's not a far stretch to ask if this psychological effect has a feedback mechanism coupled to libido and testosterone production.
I wonder how they do these studies to accommodate trans men. Is it allowed to filter these studies on birth sex rather than gender?
I can’t find good stats on the percent of trans men in the population but I imagine it’s both low, and increasing from 2007 to now.
May not be significant enough to affect the study if it includes some from random sampling, but I imagine trans men have lower testosterone than non-trans men.
Filtering by birth sex makes sense, this is a biology study, so any treatments trans men are receiving could taint the data.
Though, by that logic, they should also ignore obese men, since they also have lower testosterone levels. It's a complex issue as to who to ignore really based on their life style choices.
[+] [-] PragmaticPulp|4 years ago|reply
Obesity is still a huge contributor to reduced testosterone, and this study doesn’t disagree with that. It’s such a well-known effect that it’s one of the first things the authors note and try to account for. These studies are trying to identify factors beyond obesity and reduced physical activity, but it’s difficult to tell if they’ve developed an accurate model to subtract those effects from their study.
While it’s possible that environmental toxins like BPA can contribute to neuroendocrine disruption and should be investigated, lifestyle factors are still at the top of the list of things people can adjust to influence their own testosterone levels.
[+] [-] a_f|4 years ago|reply
[+] [-] codyswann|4 years ago|reply
[+] [-] daveguy|4 years ago|reply
I'll also add this from the article:
Setting: This was an observational study of randomly selected men residing in greater Boston, Massachusetts.
There hasn't been a slew of studies since from around the US. "American Men" is a huge stretch for such a localized study. It very well could have been one of the studies that alerted to BPA, but it could also be a very localized environmental effect.
Either way, this study should not scare anyone, except in it's overreach.
[+] [-] JohnJamesRambo|4 years ago|reply
Are you suggesting living specifically in Boston lowers testosterone?
[+] [-] doctorhandshake|4 years ago|reply
My first thought was BPA, but it appears the effects of plasticizers on the male endocrine system are mixed[1].
Still can’t help but think this is something environmental and chemical at work.
[1] https://rbej.biomedcentral.com/articles/10.1186/s12958-018-0...
[+] [-] pueblito|4 years ago|reply
I absolutely agree. I read a meta study where they concluded lab rats have been gaining fat since the 70s - and these rats have well documented genetics, very precisely controlled diets, tons of expertly collected high quality data. It was pretty damning
[+] [-] bigbillheck|4 years ago|reply
Also in the absence of longer-term or non-American data, we don't know if this is a decline from 'normal'. There's a lot of weird chemicals out there nowadays with biological effects, but there were a lot of those in the 20th century too.
What I mean is, maybe instead of 'testosterone levels are low today because of all the soy', it's 'testosterone levels were inflated back then because of leaded gasoline (or DDT or asbestos or ....)'.
[+] [-] AbrahamParangi|4 years ago|reply
[+] [-] rafale|4 years ago|reply
[+] [-] inglor_cz|4 years ago|reply
While this is generally considered a cultural change, I feel that hormonal changes cannot or at least should not be ruled out a priori.
[+] [-] jm_l|4 years ago|reply
https://lithub.com/it-turns-out-theres-not-a-lot-of-science-...
[+] [-] theli0nheart|4 years ago|reply
[+] [-] nodejs_rulez_1|4 years ago|reply
[deleted]
[+] [-] gjvc|4 years ago|reply
[+] [-] tersers|4 years ago|reply
[+] [-] GoToRO|4 years ago|reply
Women are not affected, but men get “womenized”.
[+] [-] short12|4 years ago|reply
Granted it will vary person to person. But there are major changes happening in the body that result from messing with hormones
[+] [-] throwawaymanbot|4 years ago|reply
[deleted]
[+] [-] unknown|4 years ago|reply
[deleted]
[+] [-] seventytwo|4 years ago|reply
[+] [-] goldenkey|4 years ago|reply
If anything, the soyboy superstition probably comes from just drinking sugary beverages and meals that lack sufficient fats and proteins for muscle building. Lack of cholesterol could also be an issue if one's genetics are of a low-production type.
Soy itself is somewhat of a super legume. The only legume that comes close is peanuts. And it's not very common to find peanut milk. Elmhurst used to sell it, it was amazing.
I have no problem building muscle [1] and my last free T test was around 850. Anecdotally, I doubt soymilk is the issue.
[1] https://i.imgur.com/K6kEeUD.jpg
[+] [-] visava|4 years ago|reply
[+] [-] ryanmarsh|4 years ago|reply
Dr. Shanna Swab has been on at least one big podcast that I’ve seen. The discussion was fascinating. I won’t name the podcast because people get weird about it here.
[+] [-] goldenkey|4 years ago|reply
Before you prepare to downvote me for having Christian sentiment, know that semen retention is actually an old eastern practice known to boost libido and health.
And yes, (ready for the pedants), prostate health has been correlated to unclogging old fluid in "the pipes" but that doesn't require the frequency of masturbation that is commonly practiced by single men in America.
The mental effects of constant video arousal have already been documented to be the cause of underperformance and erectile dysfunction in men. It's not a far stretch to ask if this psychological effect has a feedback mechanism coupled to libido and testosterone production.
[+] [-] Bancakes|4 years ago|reply
[deleted]
[+] [-] Factorium|4 years ago|reply
Sites should be mandated to charge a minimum fee per month (eg. $10), and ISPs should be instructed to block websites which do not comply.
In this way it will be restricted from minors, and be more easy for adults to control their own access to.
[+] [-] prepend|4 years ago|reply
I can’t find good stats on the percent of trans men in the population but I imagine it’s both low, and increasing from 2007 to now.
May not be significant enough to affect the study if it includes some from random sampling, but I imagine trans men have lower testosterone than non-trans men.
[+] [-] FastEatSlow|4 years ago|reply
[+] [-] elzbardico|4 years ago|reply
[+] [-] unknown|4 years ago|reply
[deleted]