[Knufen]

I did my Master Degree in Organic Chemistry where we tried to develop a male contraceptive pill. I spend a lot of time studying sperm so here is a short list of thing to avoid regarding sperm quality (not ranked):

1. Eating and drinking from plastics (This includes aluminum cans which are plastic lined) [a]

2. Heating food in ANY type of plastic [a]

3. Caffein intake [b]

4. Sugar intake [c]

5. NOT exercising regularly [d]

6. Alcohol [e]

7. Age [f]

8. Stress [g]

9. Soy products or other natural products containing phytoestrogens [h]

I edited the comment to add point 8 and 9.

Funnily enough these goes for both genders regarding fertility. If you are considering having a child, it takes approximately 7 months for sperm to fully develop so better to change lifestyle sooner rather than later.

a. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3222987 b. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5482951/ c. https://pubmed.ncbi.nlm.nih.gov/35606632/ d. https://rep.bioscientifica.com/view/journals/rep/153/2/157.x... e. https://pubmed.ncbi.nlm.nih.gov/28029592/ f. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3253726/ g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6260894/ h. https://pubmed.ncbi.nlm.nih.gov/18650557/

[colordrops]

With all of these it's a matter of quantity. For instance, bullet point 9 about soy makes me question this list. It turns out that phytoestrogens are much less potent than real estrogen, and the only people that were found to have measurable effects from soy was through a study of older men that ate massive amounts of soy every day in Japan. There is real estrogen in cow's milk, which would have a much stronger effect than soy, yet no one speaks about this. Hops in beer also has more phytoestrogens than soy.

[steve_adams_86]

Yes, the data around soy is incredibly underwhelming. A plant like hops does contain more, and more potent, phytoestrogens which many people consume more often than they consume soy. As you mention, milk contains mammalian estrogen which research indicates has notable impact on women’s health in particular (earlier onset of puberty, higher breast and ovarian cancer risk, etc).

Soy seems to fall well within the parameters of “this is fine”, but people readily take any example of it effecting our physiology as evidence of it being harmful. In reality, the evidence of it promoting health overall is extensive and strong.

It could be a component of a plant-based diet for example, which is shown to lead to lower BMI (great for sperm and overall health outcomes). It may reduce sperm concentration to a small degree in large volumes, but the chances are good (statistically speaking) that swapping out something worse in your diet for soy would be a net positive.

[amelius]

Does estrogen in food even enter the blood?

[sitharus]

It does, but like everything absorbed through the digestive system it gets extensive first-pass metabolism through the liver before entering the rest of the circulatory system.

Oral estrogen comes in 2mg tablets, but this results a few in µg of estrogen circulating. Estrogen also comes in transdermal patches where one 100µg patch will last three days for approximately the same dose as 4mg of oral ostrogen daily.

[colordrops]

It's sold in pill form so I assume so?

[amelius]

Lookup drug delivery systems. Getting something reliably in the blood stream is not trivial.

[ruined]

the pills are designed to be taken sublingually, not swallowed. first pass metabolism destroys most of it.

[lilyball]

They're actually not, they're prescribed orally, a lot of people take them sublingually anyway because it's more effective.

[teg4n_]

Sure some gets through when ingested, however you typically have the pill dissolve under your tongue for significantly better absorption.

[myshpa]

"Estrogens are also contained in meat and eggs, but the major sources are milk and dairy products. By drinking a glass of milk, a child’s intake of estradiol is 4000 times the intake of xenoestrogens, in terms of hormone activity. See, modern genetically-improved dairy cows can lactate throughout their pregnancy; the problem is that that’s when the estrogen levels can jump as much as 30-fold.

Though cheese intake has been associated with lower sperm concentration, dairy food intake has also been associated with abnormal sperm shape and movement, so this suggests that dairy intake may be implicated in direct testicular damage, and not just a potential suppression of sperm production due to the estrogen."

https://nutritionfacts.org/video/dairy-estrogen-and-male-fer...

"Estrogen hormones can be thousands of times more estrogenic than typical endocrine-disrupting chemicals. Dietary exposure to natural sex steroids (in meat, dairy, and eggs) is “therefore highly relevant in the discussion of the impact of estrogens on human development and health.” And chicken estrogen is identical to human estrogen—they’re the same molecule."

https://nutritionfacts.org/2016/09/13/estrogen-animal-produc...

"Foods of animal origin in general naturally contain hormones, but cow’s milk may be of particular concern. The hormones naturally found in even organic cow’s milk may be playing a role in the studies that found a relationship between milk and dairy products with human illnesses, such as teenagers’ acne; prostate, breast, ovarian, and uterine cancers, many chronic diseases that are common in Western societies, as well as male reproductive disorders. Milk consumption has even been associated with an increased risk of early puberty in girls, and endometrial cancer in postmenopausal women, but hormonal levels in food could be particularly dangerous in the case of vulnerable populations, such as young children or pregnant women. "

"Pregnant cows excrete significantly higher levels of sex steroids into their milk than non-pregnant cows. The subsequent consumption of such dairy products may mean an unnecessary risk, but one that could be easily avoided. But it’s not just dairy. Although dairy products are an important source of hormones, other products of animal origin must be considered as well.

All edible tissues of animal origin contain estrogen. This may explain why, in a study of over a thousand women eating plant-based diets, vegan women have a twinning rate that is one fifth that of vegetarians and omnivores."

https://nutritionfacts.org/video/why-do-vegan-women-have-5x-...

[s1artibartfast]

Anecdotally I know someone that had their ovaries removed as a child and did not know because their high soy diet provided enough estrogen that they had regular menstruation

[ipdashc]

I think I'm missing something. On the Results in study [b], they say

> Semen parameters did not seem affected by caffeine intake, at least caffeine from coffee, tea and cocoa drinks, in most studies. Conversely, other contributions suggested a negative effect of cola-containing beverages and caffeine-containing soft drinks on semen volume, count and concentration.

If tea and coffee don't cause an effect, but cola and soft drinks do, doesn't that imply it's sugar, not caffeine?

[Knufen]

There is an ongoing discussion on the effect of caffein on sperm quality. There are articles which describes a possible route for DNA damage to the sperm from caffein https://www.cureus.com/articles/109365-effect-of-stress-and-.... From personal (lab) experience there is a clear difference to the smell of sperm from a coffee to a non coffee drinker, so it ends up there somehow. Whether it truly has an effect is still being discussed.

[Tagbert]

Caffeine has no smell so what you are detecting is some other component or effect on the semen taste. Many things can affect the taste of semen.

[calmdownpeople]

He said smell not taste! At least I hope he wasn't tasting the lab samples.

[fnordpiglet]

Just the semen.

[vineyardmike]

“Lab samples”

[e12e]

He didn't specify difference between de-caf coffee vs regular - only coffee vs non-coffee - so might be something other than caffeine that effects smell?

[Tagbert]

Coffee contains a large number of aromatic components that could be transferred to the semen. Just the way methyl mercaptan from asparagus can be transferred to your urine.

[asdff]

What about pineapples?

[et-al]

Could be correlated to issue 1 with plastic containers. In the US, soda generally comes in aluminum cans or 2L plastic bottles, whereas coffee and tea aren't.

Anyways, I still think sedentary lifestyles and stress play a larger role than plastics, but those are harder to isolate and control for researchers.

[gabea]

Aluminum soda cans are actually lined with plastic. So either way you are going to be consuming soda from plastic.

See this link -> https://interestingengineering.com/science/new-viral-video-r...

And this one about BPA which is quite cringeworthy from Coca-Cola -> https://www.coca-cola.ca/faqs/coca-cola-faqs-health/do-coca-...

[pdpi]

Well, the two sentences following your quote read:

> 2. As regards sperm DNA defects, caffeine intake seemed associated with aneuploidy and DNA breaks, but not with other markers of DNA damage > 3. Finally, male coffee drinking was associated to prolonged time to pregnancy in some, but not all, studies.

And then goes on to conclude:

> The literature suggests that caffeine intake, possibly through sperm DNA damage, may negatively affect male reproductive function.

The whole abstract points at weak/inconclusive results, but we're definitely talking about caffeine here, not sugar.

[ljf]

Or drinks stored in plastic bottles or plastic lined cans? Vs tea/coffee brewed and served in metal/ceramic vessels?

[UglyToad]

Ah yes, that study of 99 (predominantly overweight) men from an infertility clinic that definitely shows soy affects sperm count.

As far as I'm aware the evidence just isn't there with respect to soy and cherry picking the single study that shows some potential link is just helping fuel a dietary myth, would be my view.

[dang]

Can you please make your substantive points without being snarky? This is in the site guidelines: https://news.ycombinator.com/newsguidelines.html.

This is particularly important when correcting misimpressions. If your comment is neutral, the neutral reader can absorb the new information fairly easily. But if you're hostile (as with "ah yes, that, definitely that"), then you're also signaling a pre-existing battle. The neutral reader gets confused by these mixed signals and feels caught in crossfire, which is not a state that's good for learning.

The upside of battle language is that it rallies any readers who are already on your side, but this is not a good move in the HN game. We want curious conversation here, not escalating intensity or repetition of already hardened positions. The value of curious conversation can perhaps be measured by how much the participants, including the silent readers, move in the process.

[justnotworthit]

Of all the worthless, flame-inducing posts in hacker news comments, "Ah yes, that study" is the example that need to be highlighted?

[Noumenon72]

It may be more educational to contest one that most readers might not realize is problematic (I didn't bat an eye) than one that is obviously flamebait.

[andrewflnr]

As a general principle, explaining edge cases are helpful for elucidating tricky distinctions.

[dang]

I've done that at least 40,000 times. This isn't a linear ordering!

There are many principles, which we're discovering together, around curious conversation. I went into this one in detail because I think it's interesting.

Btw, if you see a post that ought to have been moderated but hasn't been—for example, a "worthless, flame-inducing" one—the likeliest explanation is that we didn't see it. You can help by flagging it or emailing us at [e-mail].

[UglyToad]

Thanks for the reminder, while I might not agree on an individual level where the line between calling out misinformation and partisan-bad-faith-point-scoring lies I think despite the repeated edits I was over the line here.

While it feels good to post, it doesn't really help the quality of discussion.

[Klonoar]

Yeah, I feel like the soy myth has been disproven time and time again but won’t die already.

This and seed oils get hit with the exact same playbook, then disregard significant chunks of the world that have zero issues with them.

[UglyToad]

Yeah, like I get people maybe being wary of soy. There's a lot of mistruths and half understood myths out there. In addition to various contradictory findings from studies [0].

But for a list speaking from a position of expertise it felt quite jarring to see it included as a definitive "don't" and made me wonder about the agenda of GP (soy with respect to fertility is indelibly linked with the far-right "soyboy" meme).

As a chemist the idea that phytoestrogens might have the same impact as estrogen isn't completely buck-wild, but also as a chemist I know that two isomers with the exact same composition can have wildly different effects in the human body. So I'd need to see a lot of solid evidence before treating is as anything more than a myth spread by misinterpreted studies of red-clover consumption in Australian sheep from the 1940s.

[0]: https://www.fertstert.org/article/S0015-0282(10)00368-7/pdf

[vladvasiliu]

> But for a list speaking from a position of expertise it felt quite jarring to see it included as a definitive "don't" and made me wonder about the agenda of GP (soy with respect to fertility is indelibly linked with the far-right "soyboy" meme).

I can see why that would make you wonder. However, a few years ago, the French TV did a take on soy and products containing derivates [0] (French only, unfortunately). It warned about possible effects on the endocrine system.

In relation to your point, there are two notable things:

1. It focused mainly on effects in females (never heard of a "soygirl" meme)

2. French TV is not affiliated with the alt-right (or any right) in any way, shape, or form. It has a reputation of being quite left-leaning. And that's by French standards.

[0] https://www.francetvinfo.fr/sante/alimentation/perturbateurs...

[steve_adams_86]

I haven’t found anything compelling about seed oils being awful, but I haven’t found anything indicating that we should actually eat them, though. Have you?

I’m asking sincerely. It seems to me like they’re better than some alternatives if only to reduce saturated fat intake, but generally speaking, if any refined fat is avoided it’s probably to your benefit.

I often wonder if people think seed oils are bad because they eat way too much of it in general. Kind of like, if you take a shot of windex every morning you shouldn’t be surprised when you become ill, but instead people expect it to make them healthy (not actually comparing canola with windex).

[hombre_fatal]

https://www.the-nutrivore.com/post/a-comprehensive-rebuttal-...

Canola oil in particular seems most interesting. Its nutrient composition is more impressive than olive oil.

As for your theory, seed oils only make up 7% of US diet calories. Saturated fat makes up more than twice that. Replacing saturated fat with canola seems like an uncontroversial outcome improvement.

[steve_adams_86]

Wow, I was unaware of the 7% figure. And thanks for this article too, it’ll make for good reading later.

I’m certainly in favour of exchanging saturated fat for canola. I believe it was Finland where they made a big push to use canola rather than butter and the health outcomes seemed significant. There were confounding factors, but nonetheless, it was clear that a reduction in saturated fats yielded better life expectancy and lower rates of heart disease. The results were actually in line with what prior research indicated. Finland went from a lowest life expectancy in the world to one of the highest over decades, likely in part because of that transition away from dairy fats.

In that sense I think canola is amazing. I personally avoid both (of course it’s impossible to do so 100% of the time), but I fully support people choosing relatively healthier options.

[ohbleek]

Anecdotally, while living in Finland for a number of years I found that most households I knew would mix margarine and butter together 50/50, and that was the only form they used outside of cooking and baking.

[35amxn35]

Perhaps the correlation is the other way around. Men with less testosterone (and therefore a lower sperm count) consume more products with soy, which is common in a vegan diet. Not saying this is the case, just pointing out where this could be coming from.

[fredrikholm]

Are you implying that having low testosterone increases the likelihood of you becoming vegan? I'm not following.

[35amxn35]

Yes, exactly.

[fredrikholm]

How did you arrive at that conclusion? The only studies I could find show no such correlation[0][1].

I remember reading that vegans had higher levels of testosterone when not controlling for body weight, as vegans tend to be less obese than non-vegans. Can't find the source, so pinch of salt here. Makes sense though.

0. https://pubmed.ncbi.nlm.nih.gov/32468110/ 1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2374537/pdf/83-...

[steve_adams_86]

Is there evidence of this being true, or is it a hunch?

[myshpa]

"Vegan men tended to have significantly higher testosterone levels than both vegetarians and meat-eaters (see graph https://nutritionfacts.org/video/how-plant-based-to-lower-ig...)"

https://nutritionfacts.org/2013/02/12/less-cancer-in-vegan-m...

"You know, there are men who don’t want to drink soy milk because they have an irrational fear of phytoestrogens—even though soy does not have feminizing effects on men. Yet they’re perfectly willing to drink cow’s milk, which has actual estrogen estrogens in it! Within one hour of the milk hitting their intestines, estrogen levels go significantly up, and testosterone levels go significantly down."

https://nutritionfacts.org/video/dairy-sexual-precocity/

"If you take men on a high-protein diet—”meat, fish, poultry, egg white[s]”—and switch them to a high-carb diet of “bread, vegetables, fruit, and [sugary junk,]” their cortisol levels drop about a quarter within ten days. At the same time, their testosterone levels shoot up by about the same amount. High-protein diets suppress testosterone. That’s why if you take men eating plant-based diets, and have them start eating meat every day, their testosterone levels go down, and actually some estrogens go up.

That’s why bodybuilders can get such low testosterone levels. It’s not the steroids they’re taking. If you look at natural bodybuilders, who don’t use steroids, 75% drop in testosterone levels in the months leading up to a competition. Testosterone levels cut by more than half; enough to drop a guy into an abnormally low range. It’s ironic that they’re eating protein to look manly on the outside, but it makes them less and less manly on the inside. And, from an obesity standpoint, in general, a drop in testosterone levels may increase the risk of gaining weight—gaining body fat."

https://nutritionfacts.org/video/the-effect-of-animal-protei...

[spfzero]

What about having low testosterone would make someone eat more products with soy?

[lr4444lr]

Comments like this from commenters like this are why I love HN.

Does BPA-free plastic improve anything? What about containers of non-prepared food? I can see not eating directly from any, but I think it's pretty hard in the developed world to rid ourselves of plastics entirely in the storage of foodstuffs.

Also, do we know whether the changes in sperm quality you mention affect congenital childhood maladies? (I realize this is probably beyond your field somewhat.)

[Scaevolus]

BPA is merely one of many endocrine disrupting chemicals found in plastics. Oftentimes BPA is replaced by BPS or BPF to get that coveted "BPA-free!" label, ignoring the fact that the replacements are JUST AS BAD^1. It's a minefield.

Silicone tends to not have endocrine disruptors because it doesn't need plasticizers.

[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4492270/

[Knufen]

All plastics are endocrine disruptors [a], though the an easy filter is softer = worse. If anything food related is in contact with plastic there will be plastic in the food. The pH and temperature of the food have a big impact on plastic leaching.

And sperm quality mostly affect fertility. The egg and the body if the woman is incredibly effective at selecting quality sperm and rejecting bad sperm. There are multiple guidance systems for sperm which selects for good quality [b].

a. https://www.niehs.nih.gov/health/topics/agents/endocrine/ind... b. https://en.wikipedia.org/wiki/Sperm_guidance

[fnordpiglet]

Plastic is generally defined by its mechanical and thermal properties and a dominance of polymers. There’s are lots and lots of different chemicals used as plastics today and they have wildly different chemical properties. It seems incredible to state that “all plastics” are endocrine disruptors. Many plastics are essentially chemically inert in a biological sense. In some ways DNA itself can be seen as a plastic being a biopolymer if it were handled properly and in enough quantity. As an uneducated layman my intuition, and the links you provide, is that the additives and monomers added to plastic to modulate their mechanical and chemical behaviors are most likely to be the chemically reactive part that can be disruptive to our biology. I didn’t find a reference to a single plastic in your references. This applies to the leaching comment as well - I suspect you mean ph and temp increase the leaching of the additives from the plastic.

Am I right?

[chordalkeyboard]

plasticizers are a component of plastic, characterizing one ingredient in plastic as an 'additive' in order to shift the blame from plastic to plastic ingredients doesn't change the basic fact that plastics are endocrine disruptors because they leach plasticizer into food.

[fnordpiglet]

Just because plasticizer has the word in its name doesn’t make it plastic. Nylon, PLA, PET, ABS, these are plastics. As far as I can tell they are not endocrine disruptors, and they are polymers - aka plastics. They require no other “ingredients” and can be used in an unadulterated form for many applications.

Phthalates are monomers (aka not plastics) that are added to plastics to change physical properties of a plastic, such as flexibility, durability, make them more transparent, etc. They’re in fact derived from alcohols to my memory, and have no relationship to plastic. But they are also called plasticizers because they make plastics behave more “plastic” (in the adjective sense not the chemical sense). They are also suspected of being endocrine disruptors. But they’re not “plastic ingredients” - their use is optional and there exist alternatives.

It is in fact an important distinction. There are other plasticizers that are not biologically active that can be used in place. Or, plasticizers don’t need to be used at all. Both of these options make the plastics benign.

It’s an important distinction because plastic isn’t the problem at all, it’s the regulatory framework around plastic additives, none of which are strictly necessary and there are almost always safer alternatives. Plus it’s important to distinguish because it’s simply false to say plastics are a an endocrine disruptor when they aren’t, even if it’s convenient to get your point across.

[coryrc]

ABS is only partially a plastic.

You can't avoid a plasticizer and still use i.e. PVC for the vast majority of its consumer use cases, which is what you are alluding to (I think) but you also can't just use the same molds and design with a different plastic. Of something's designed for UV resistance, you can't use the same design with an environmentally-friendly plastic. Like, it would have to be designed to be painted or metallized or something. At this point it's a different product: the products as currently made must be outlawed. No more aluminum cans with soda. No more lightweight waterproof jackets.

[klipt]

Right but in the absence of regulation, I would treat with suspicion e.g. fast food in any plastic container (or waterproofed "paper" container which usually means a plastic layer too).

I consider glass, stainless steel, and cast iron safe, and try to avoid almost anything non stick or plastic for cooking/food storage.

[philipkglass]

Not all plastics contain plasticizers, so I would say that fnordpiglet is correct. For example, low density polyethylene (commonly used for jugs holding milk and water) is flexible without addition of any plasticizers. For this reason it is also used in laboratory equipment where plasticizer contamination would interfere with experiments:

Low density polyethylene (LDPE) is a high molecular weight polyolefin material. Like all polyolefins, LDPE is nontoxic, non-contaminating and exhibits a high degree of break resistance.

The polymerization of polyethylene results in an essentially straight chain, high molecular weight hydrocarbon. The polyethylenes are classified according to the relative degree of branching (side chain formation) in their molecular structures, which can be controlled with selective catalysts. LDPE has more side branching than HDPE resulting in a less-dense 3-D structure. As a result, LDPE is naturally very flexible without the addition of plasticizers and melts at a relatively low temperature (85°C).

https://www.thermofisher.com/us/en/home/life-science/lab-pla...

[fnordpiglet]

You should say I’m correct more often, then I can reference that for my wife’s benefit.

[a1369209993]

> In some ways DNA itself can be seen as a plastic being a biopolymer if it were handled properly and in enough quantity.

To be fair, DNA absolutely disrupts all kinds of biological processes - that's why viruses do anything, for example. And random nonsense DNA that you'd see if someone was using it as a plastic would probably uncover new and exciting failure modes that existing biological systems haven't had to deal with before because nothing natural produces pure DNA in absurd enough quantities to make plastic bottles out of.

[tomp]

Not really, no. For obvious reasons, genetic material is very hard to get into a cell. The immune/digestive system fights it!

That’s why mRNA (BioNTech & Moderna) and DNA (J&J) vaccines took so long to develop!

[a1369209993]

> For obvious reasons, genetic material is very hard to get into a cell. The immune/digestive system fights it!

That's quite true, but it's true precisely because it's horrifically disruptive. (And the immune system has had more time to evolve protections against that disruption than it has for previously unheard of synthetic polymers.)

(Although to be clear, the new and exciting failure modes probably wouldn't involve the synthetic DNA actually getting inside of cells. (Sheer quantity might be sufficient to shove it's way through a phospholipid bilayer, but probably not.))

[lm28469]

> What about containers of non-prepared food?

Wait until you learn about ink contamination from food nets and cardboard boxes.

[throw0101a]

> 1. Eating and drinking from plastics (This includes aluminum cans which are plastic lined) [a]

So drinking containers should generally be ceramic, glass, or stainless steel?

[yamtaddle]

I'd want to know that drinks aren't full of that stuff regardless of the end-user container material, before worrying about it. They're surely exposed to tons of plastics in the manufacturing process, including at times when various components are heated.

Even water supplies in a house will typically have been in contact with plastics—at the treatment plant, in the house for any modern house (they're pretty much all PEX now, since it's stupid-easy and fast to install, which means it's very cheap), in the hot water heater if they're any hot water mixed in (ever start with a hot tap for water you're gonna boil?), if you've got a filter system that's almost certainly full of plastic, and so on.

You'd also have to avoid canned goods of all kinds, not just bottled/canned drinks. Store-bought canned foods have plastic liners, which all but completely solved problems with canned-good spoilage that we used to have, but does mean ~all canned goods are sitting in plastic, not metal, effectively. Glass-canned might be better but are usually more expensive and there's still plastic on the inside of the lids (how much that matters, I do not know—I'd expect very little, but sometimes these things are surprising, for all I know those inside-the-lids bits use exceptionally awful plastic or something).

[agentwiggles]

> ever start with a hot tap for water you're gonna boil?

I've been told I shouldn't do this, so I don't, but I always feel like a rube waiting for a big pot of pasta water to boil from cold when I know I could have just used my giant tank of heated water and save 10 minutes of waiting...

[sitharus]

That's due to old-fashioned plumbing. Wayyy back in the day when water networks were fairly new they often couldn't provide the water pressure we have now, especially in hilly areas. It was fine for cold water, but not enough to pressurise a hot water tank.

The solution was a header tank in the attic. This stored water from the supply and fed it down to the hot water cylinder, providing some pressure.

The problem is the header tanks weren't a sealed system so animals could make their way in. In particular when using rodent control poison as this makes them seek water. Generally it'd be noticed pretty quickly, but not immediately.

So the hot water was generally safe for washing but shouldn't be used for drinking or cooking.

With modern closed systems (from the 70s onwards really) this isn't an issue.

[coolspot]

Where I am from we are having centrally-heated water, so we were told that hot tap water has anti-scaling chemicals unlike cold tap water which has only excessive chlorine.

[throw0101a]

> With modern closed systems (from the 70s onwards really) this isn't an issue.

The water department for the City of Denver still recommends not to use hot water:

> Hot water systems like tanks and boilers contain metallic parts that corrode as time goes by, contaminating the water. Hot water also dissolves contaminants in pipes faster than cold water.

* https://www.denverwater.org/tap/psa-dont-drink-or-cook-with-...

Also Vancouver (BC):

> Confused, I decided to send the question over to Metro Vancouver, which provides water to most of the 2 million residents in the Vancouver region. Bill Morrell, Metro’s media relations guy, quickly got me this answer from Bob Jones, their water quality expert. The bottom line: Use cold water for boiling.

* https://vancouversun.com/news/staff-blogs/why-you-shouldnt-u...

EPA:

> 2. USE ONLY COLD WATER FOR COOKING AND DRINKING. Do not cook with, or drink water from the hot water tap. Hot water can dissolve more lead more quickly than cold water. If you need hot water, draw water from the cold tap and then heat it.

* https://www.epa.gov/sites/default/files/2015-09/documents/20...

[dabluecaboose]

Worth mentioning that hot water is also better at dissolving things than cold, which is why aquarists should avoid putting anything from the hot water tap into their aquariums. It can introduce copper which is bad for my shrimp.

[myshpa]

I think it's because of the bacteria living in hot water, and some toxins are resistant to boiling.

[yamtaddle]

Yeah, I don't either, but I'd be surprised if most people don't use the hot tap for stovetop-bound water.

[anikom15]

There’s always a chance that there’s a dead animal in your water heater

[gambiting]

I mean.....I don't know about elsewhere, but here in UK you just have a combi boiler, there's no storage.

[anikom15]

Anywhere with abundant natural gas (like America) will mostly have tank water heaters powered by gas.

[yamtaddle]

I'm torn between wanting more information, and preferring to live in blissful ignorance.

[gambiting]

In old houses if you had a hot water storage tank in the attic it was usually just covered with styrofoam or a metal or wooden slab, it wasn't uncommon for an occasional insect or yes, a small rodent to fall in and die in there. It's one of the reasons why most houses in the UK had separate cold and hot water taps - cold water was considered safe to drink, hot not so much.

Nowadays if you have a hot water cylinder it's impossible for anything to get in there(although there is still a chance of bacteria growing inside the tank, but any modern cylinder will periodically heat itself to very high temperature to kill any pathogens)

[anikom15]

It could be a bird, a bat, or a victim of bipolar disorder.

https://en.m.wikipedia.org/wiki/Death_of_Elisa_Lam

[bmicraft]

No, my water runs through a heat exchanger

[throw0101a]

> (they're pretty much all PEX now, since it's stupid-easy and fast to install, which means it's very cheap)

Also good in cold climates as they can stretch if the water expands after freezing: they'll shrink back to the original size (esp. PEX-A/Uponor) which may help reduce the chances of the house being flooded.

Once copper bursts that hole is permanent.

[lm28469]

> ever start with a hot tap for water you're gonna boil?

Depending on your system this might have no impact, my hot and cold water come from the same place and the hot water is heated 1m away from my sink by an electrical heater

[mauvehaus]

Or titanium[0]. Neat fact about anodizing titanium: the colors are the result of the thickness of the resulting oxide layer and how it refracts different wavelengths of light[1].

[0] https://www.snowpeak.com/collections/drinkware/products/tita... There are many. This is my favorite.

[1] https://chemistrytalk.org/titanium-anodizing/

[Knufen]

Generally yes. Beware of drinking bottles made from stainless steel. A lot of them are lined with plastic to avoid the metallic taste.

[mc32]

Or leather water bottles as well.

[floren]

Do you know of any that don't have a liner of some sort? I'd be interested in trying one but wouldn't know where to get one.

[mc32]

I think Viking Dragon makes some handmade ones. Being handmade they are not cheap, but I wouldn't call them too expensive either.

[dj_mc_merlin]

I might as well stop using condoms.

[themagician]

Switch to PS5 + Mountain Dew. 30 minutes before sex, microwave a cookie in tupperware and drink a beer. For added protection, download the critically acclaimed MMORPG Final Fantasy XIV. With an expanded free trial which you can play through the entirety of A Realm Reborn and the award winning Heavensward expansion up to level 60 for free with no restrictions on playtime.

[ChuckNorris89]

Can't get a PS5. Does a Nintendo switch also do the job?

[themagician]

Unfortunately, the Switch is only about 90% effective in preventing unwanted pregnancy. PS5 is 98%.

[ghostbrainalpha]

I found the Switch to be highly effective as preventing pregnancy if you keep it in handheld mode and bring it to bed with you.

When partner attempts romantic activity, tell them you need 5 more minutes of Pokémon and the problem is solved completely.

[themagician]

Ah, the famous "pull out" method. Pull out the Switch right as you get into bed.

[danuker]

I suppose it's a good idea, if you're trying to conceive :)

[glitchc]

He's become.. Inconceivable.

[moffkalast]

You keep using that word, I think it means what we think it means.

[grammers]

This more or less reads like any health instruction (except for the soy products). Would you have a quantity as to how one can change plastic intake by following these recommendations? How strict does one need to be? - I mean basically everything you buy is wrapped in plastic...

[mikodin]

This isn't based on anything except for intuition, take it or leave it :).

Like most things - eliminating the highest points of contact likely would suffice.

Daily habits are the ones that matter.

Are you drinking from a plastic water bottle everyday? Is your water filter plastic? Are you drinking coffee from a keurig or similar? Are you storing food in plastic containers? Are you heating food in plastic containers? Are you using plastic utencils? Are you using plastic lined pans? Are you buying food wrapped in plastic?

Etc etc.

It's a good starting place...then get your sperm tested, it's not prohibitively expensive.

[siglesias]

I cannot recommend highly enough having a set of glass bottles[1] at home. Fill them at the tap (or wherever), refrigerate them, take them to the gym, in the car, serve to guests. Point is to have many, keep a rotation going. Has greatly reduced reliance on plastic.

1) https://amzn.to/3H2YadV

[SoftTalker]

Gyms often ban glass bottles because of the hazard they create when dropped/shattered.

I personally use a hard (i.e. not squeezable) plastic bottle, that I fill with cold/cool water just before use. As long as the water has not been sitting in the bottle for days or in the sun or in a hot car, etc. I don't think there is enough potential chemical leeching to worry about.

[djmips]

Any reason to not use a Yeti cup or similar stainless steel thermos cup?

[Bud]

Wouldn't metal be far preferable? Especially double-walled metal bottles that can hold liquid at a temperature.

They don't break.

I do have some glass bottles as well for occasional use by guests, but when on the go, the popular metal water bottles seem best.

[zhynn]

You can often buy milk at a coop in a glass bottle which can then be reused. Most of our beverage consumption is out of re-used milk bottles. :)

[bluGill]

In my state it is illegal to use a glass milk bottle for anything other than milk from the dairy that the bottle is from. The law is from many years ago, and so there are a lot old bottles from now-defunct dairies that legally cannot be used even though everyone does.

[irusensei]

> here is a short list of thing to avoid

> 7. Age [f]

wait wat

[nzealand]

Age is also best avoided as it is the number one cause of bodily deterioration, disease and death.

[mauvehaus]

Perhaps, but as death almost certainly assures a sperm count of zero (and some weird looks if you try collecting a sample), aging is probably preferable if you're trying to reproduce.

[moffkalast]

Dammit, I wish I knew that before I started aging!

[simonsarris]

"Avoid waiting (delaying) key life things you know you want" is actually great advice that even very smart people seem to fail to consider.

[nmfisher]

We (38) had our first child this year, and if there's one thing I wish I had done, it's had kids earlier. Probably in my late 20s. We didn't have any complications during pregnancy but it would have given me 10 more years to see my boy grow and would be physically easier on my wife.

Financially it would have been more difficult, but by no means impossible. On the other hand, I probably wouldn't have taken the opportunity for a complete career change, which would have made me miserable.

So if you hit professional/romantic stability in your 20s, I'd strongly encourage you to have kids as soon as possible.

[SoftTalker]

Yes. In terms of best outcomes, you should have kids in your early 20s. Gametes are at their best, mother's body is young but fully developed and has the best chance at carrying the pregnancy to term without complications.

Financially, or in terms of career and other life goals, are other matters.

[majkinetor]

Technically, you can easily avoid age :)

[irusensei]

Oh that went dark really fast lol

[agilob]

Find a younger partner?

[danuker]

Amazing! Thanks for the well-researched info. I did not know aluminum cans were lined. I thought the oxide layer is stable enough.

[bluGill]

The acid in carbonation will eat the oxide layer, so soft drink cans get a thin plastic lining. Alcohol cans often are not lined.

[moffkalast]

I think they just spray them with a thin layer of epoxy, otherwise certain drinks get a metallic taste?

[citizenpaul]

>it takes approximately 7 months for sperm to fully develop

Can you explain this more? I was under the impression it took something like 60days for sperm to generate in the body.

[10g1k]

Agree 100%. I don't eat foods with added processed sugars. I treat sugar like a spice, just throw a pinch in with a few recipes. Sugar is in just about everything in the supermarkets, and is screwing up the entire population.

[torginus]

It is surprising to me that consuming dairy products is not on that list. After all milk is produced by lactating animals (whose lactation is sometimes induced by feeding the animal artificial estrogen). It seems like a fairly direct vector to me.

Why is this so rarely discussed?

[steve_adams_86]

Worth noting is that sperm concentration was the only notable impact of soy consumption, leaving other measured aspects of sperm health unaffected (notably sperm motility, a critical factor in assessing sperm health).

[irrational]

Growing up we never microwaved food in tupperware, but we do it daily now. None of me or my siblings (8 of us) had any sort of mental issues (and it wasn't a matter of not being diagnosed), but all of our children have so many mental issues (depression, anxiety, pulling hair out, ADHD, etc.) that we have asked each other if it could possibly be something in the environment - even though all of us live in different states/cities. Maybe we all reheat food in tuperware and eat/drink from plastics.

[faximile]

This might help me cut down my Coke Zero consumption. Thanks!

Can you suggest any reputable sources for keeping up to date with these best practices, from a consumer PoV?

[grammers]

Thanks for sharing, these studies are extremely interesting!

> Because we can identify existing, relatively inexpensive monomers and additives that do not exhibit EA, even when stressed, we believe that plastics having comparable physical properties but that do not release chemicals having detectable EA could be produced at minimal additional cost.

The only question that I have left: Why aren't we doing this already???

[Aachen]

Just a small note: I noticed that I read your disclaimer that it's not in ranked order, and then went on curious to see what is the #1 cause, and had to remind myself that no it's not ranked. It might help stupid readers like me to use dashes or similar for lists when the order isn't particular, rather than numbering the items!

[concinds]

"Sugar" doesn' seem to include fruits, thankfully. https://pubmed.ncbi.nlm.nih.gov/29266782/

[mikenew]

From what I understand, there is somewhat of a threshold in terms of how much fructose can be digested in your gut vs requiring your liver to get involved. It depends on a lot of factors (body size obviously, your overall calorie intake, some genetic factors, etc), but in general of you're only consuming a few grams of fructose and it's buffered by fiber, you're probably not exceeding that threshold. Fruit fits that bill, unless you're being weird and consuming a whole lot of sugary fruit.

There's a very good interview on the topic here: https://youtu.be/V02z9mqTWzg

[adrian_b]

There is no real difference between eating food to which refined sugar has been added and eating sweet fruits. The sugar is not bound to anything and it is released in the fruit juice when the fruit is chewed, so it is not digested more slowly than when eating a sweetened cake with the same proportion of sugar (but the cakes are frequently made much sweeter than the fresh fruits).

The great danger that has been created by the availability of cheap refined sugar and similar sweeteners, like HFCS, is that it has become extremely easy to create food that has an unnaturally high concentration of sugar or fructose and that it has become extremely easy to eat an excessive amount of sugar per day.

Most cultivated fruits contain around 10% sugar, while a few are sweeter than that, with up to around 16% sugar, like grapes, fresh figs or fresh dates.

When eating only fresh fruits or defrozen fruits, it is unlikely to eat too much sugar, but it is still possible.

It is recommended that the daily intake of sugar should not exceed around 50 g (i.e. around 25 g fructose).

That corresponds to around 300 g of grapes, or around 500 g of apples or pears or blueberries (or most other fruits), so eating amounts less or equal with these every day should be safe.

On the other hand, a single chocolate might contain over 60 g of sugar. Most industrially-made food, including juices or yogurts or breakfast cereals, contains excessive amounts of sugar, so many people eat daily 100 to 200 g of sugar, or even more, without being aware of this.

When eating dried fruits or honey, it is also possible to eat too much sugar without a lot of effort, e.g. around 80 g of most dried fruits is enough to provide the maximum recommended daily intake of sugar.

[Xeoncross]

> There is no real difference between eating food to which refined sugar has been added and eating sweet fruits.

Yeah, I've heard people say this, but I can tell a big difference between people who eat a lot of fruit and people who eat a lot of processed sugar.

It's right up there with saying eating an avocado is going to make you fat because of all the calories it has so you should eat a hamburger with half the calories instead.

[adrian_b]

I have already explained why this happens.

The fresh sweet fruits have a relatively low sugar content, so when eating them you will usually have enough before eating too much sugar, e.g. if you eat a half of kilogram (a pound) of fresh fruits each day that is still OK.

When pure sugar is added to food, most people, and especially most industrial producers, add far too much sugar, so it becomes very easy to eat too much sugar each day, while eating just a small amount of sweetened food, which does not cause satiety.

The only difference between sweet fruits and sweetened food is in the quantity of sugar, not in its quality.

If one eats, for example, 2 kilograms of sweet fruits each day, then that would still cause health problems eventually, even without any added sugar, like in the geese traditionally fed with figs, to make foie gras. The effect of eating food with too much sugar, which destroys the liver, has been well known for thousands of years, even before pure sugar became known in Europe.

If sweetened food is eaten in a very small quantity per day, it does not have any other effect than eating sweet fruits.

[majkinetor]

Yeah, right... Totally believable.

[agilob]

Let's not forget how many people were born thanks to alcohol

[moffkalast]

Alcohol now working overtime to somewhat re-address the balance.

[commandlinefan]

> list of thing to avoid > ... > 7. Age

Well, I'm trying my best...

[Conscat]

I'm not sure you have any credibility considering point 9.

[faximile]

They cited a study. If you disagree, please raise the bar, and either challenge the study, or cite something compelling.

[TurkishPoptart]

>1. Eating and drinking from plastics (This includes aluminum cans which are plastic lined) [a]

How do we avoid this? So no Costco plastic water bottles, ever.

[thedorkknight]

>short list of thing to avoid

>7. Age

I find this to be the hardest one to avoid!

[Teknoman117]

9. You just can't win can you?

Eat meat, increase risk of heart disease. Eat soy, decrease fertility.

Life is weird to me. Humans have one of the longest lifespans among mammals, yet we seem to start breaking down not all that far into it. We don't tend to consider 35 "old", as we regularly live 80+ years, and even if you consider the "generally well functioning" span of your life to be your years up to 60 or so, 35 is barely past half way.

Oh well.

[jahewson]

The heart disease thing is probably bogus https://bigthink.com/health/red-meat-cancer-not-health-risk/

[brushfoot]

The soy study is far from conclusive - it showed an inverse association between soy intake and sperm concentration, but mainly in "overweight and obese men," and "total sperm count, ejaculate volume, sperm motility, [and] sperm morphology" remained the same. NEJM Journal Watch stated the findings were inconclusive and recommended against suggesting dietary changes [0].

Either way, soy vs. meat is not the dichotomy it's sometimes presented as in political narratives. You can eliminate both and still have a huge number of healthy world foods to choose from. The Mediterranean I had recently was delicious and soy and meat free.

[0]: https://www.jwatch.org/jw200808070000002/2008/08/07/do-soy-f...

[lm28469]

Half of the west eat and live as if they were attempting a slow suicide. Take care of your body and you'll be healthy well into your 60s, unless you're afflicted by outlier events but you can't do anything about these, maximise what you can, fate will do the rest

[moffkalast]

Life is a known cause of death.

[tdaltonc]

Those all have measurable effects.

But at a population level, which of those are actually driving meaningful fertility decline?

[FollowingTheDao]

EMFs????

https://www.sciencedirect.com/science/article/pii/S230505001...

https://www.sciencedirect.com/science/article/pii/S016041202...

[ceedan]

ibuprofen and acetaminophen also affect quality, which are daily medicines for some people with chronic pain.

[DoingIsLearning]

> acetaminophen

That's paracetamol for the rest of the world in case you were confused like I was.

[ChrisPebble]

I was curious about this and looked it up on google trends. It looks like acetaminophen is the more commonly searched term.

https://trends.google.com/trends/explore?q=paracetamol,%2Fm%...

[zerocrates]

I get the results I'd expect: acetaminophen is the vast leader in the US and Canada only, while paracetamol totally dominates essentially everywhere else and is by far the more searched term globally.

[SoftTalker]

Neither of these are safe for long-term daily use.

[aidenn0]

> Funnily enough these goes for both genders

So eating and drinking from plastics lowers sperm quality in women too?

[Knufen]

No, but it does affect fertility, as well as various cancers. Breast cancer: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7286136/, cervical cancer: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4801991/ and fertility: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5479690/

[sc90]

In an episode of Succession, Logan was drinking a smoothie that contained Maca Root, Almonds, and Walnuts apparently to boost his Sperm count/chances of having a kid according to Willa. Your list is more of "Dont's". Are there "Dos", based on diet or certain foods that increase the count significantly?

[sizzle]

7 months?? I thought I read it was 120 days, anyone have a reputable source?

[spacedcowboy]

Avoiding age doesn't seem like a great plan for sperm viability ... :)

[addingadimensio]

Careful — saying that plastic is turning the frogs gay is a dangerous right wing conspiracy theory

[Knufen]

Though it is a funny Alex Jones quote there might actually be some meat to it.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC122794/

[kccoder]

Is lower sperm count correlated with a change in sexual orientation?

[asguy]

The Alex Jones motto: Even a stopped clock is right twice a day.

[creaturemachine]

I thought that was the goblins' doing.

[tdehnel]

Cool so my whole life

[rafaelero]

What a list like this misses is some sense of proportionality. We don't need to stress over everything that causes fluctuations on sperm count. The science is not there yet, but personally I am going to bet >50% of the reason for decreased sperms count is because of high protein diets (which correlate to lower testosterone) and high BMI.