Luke O'Neill

speaker

4,575 appearances 24 recordings 2 series first heard Apr 2026 last heard 4d ago

Luke O'Neill’s voice in public audio — every appearance, attributed to the second.

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Recordings per month over the last 12 months — 24 in all, peaking in Jul 2026 with 6.

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Show Me the Science with Luke O'Neill · The Science of Sperm · 20 Aug 2026 podcast

There's a few reasons.

Um they don't fully know, but a big one is testosterone.

And at that conference, they announced testosterone has fallen as well.

And again, it's almost halved.

percent actually, forgot the exact number, over the past fifty years, the average level of testosterone in men has halved.

Now why is testosterone important?

Well it does all kinds of things, as I guess everybody

He knows.

It gives men their male traits, facial hair, for instance, muscle mass response to testosterone.

But a very important extra function is getting sperm to grow.

So testosterone is the hormone in the man's body that allows sperm to grow.

Now, if you have low testosterone, you're going to get less sperm, and they think that's a big reason for this.

And it was a really interesting study because it was six separate studies in different locations.

And remember, one of my mantras, look at the

Numbers, if it was five people, you'd say that's not true.

Uh in one place, not true either, probably.

Uh it was USA, Bris uh Brazil, Finland, Denmark, uh, nearly 120,000 men were looked at between 1972 and 2019.

So big study, and they noticed on average the testosterone levels were plummeting, and overall a 54% decrease.

Now they factored in aging, just in case you wonder, because people are getting older.

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