
Sperm counts are on the decline – could plastics be to blame? - onetimemanytime
https://www.theguardian.com/us-news/2019/may/24/toxic-america-sperm-counts-plastics-research
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YUMad
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.

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

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YUMad
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.

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technics256
[https://www.nature.com/articles/s41598-019-39913-9](https://www.nature.com/articles/s41598-019-39913-9)

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YUMad
Thanks!

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dTal
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.

