Sperm counts are on the decline – could plastics be to blame?

theguardian.com

17 points·onetimemanytime··9 comments

It is partly a problem, but a big part is the demonization of animal fats in the west, especially cholesterol. Our bodies use cholesterol to synthesize testosterone. Low intake of cholesterol=low testosterone. Vitamin D is also necessary, and most men in west are deficient.

I find it odd how little they talked about testosterone. Testosterone levels have been decreasing quite significantly over the years.[0]

[0] https://www.forbes.com/sites/neilhowe/2017/10/02/youre-not-t...

There was recently a study that found the same decline in dogs, which suggests an environmental cause.

That is very interesting, could you link it?

I wonder if they controlled for store-bought food vs meat-fed. First thing that comes to mind is that most dogs are fed processed, mostly vegetable-based food these days.

https://www.nature.com/articles/s41598-019-39913-9

Thanks!

People ate way less meat a few decades ago and hence less cholesterol. I don't see how this could be a factor.

Sure, but I said 'animal fats'. Lard was used extensively in those times.

There are probably multiple interacting factors - but while we're all piling on with pet theories, here's one I don't see mentioned enough: simple lack of exercise (and sunlight). Globally, people are more sedentary than ever. Exercise boosts testosterone.

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