Aaron Boster

This is a really, really great topic.

And for starters, MS is super complex.

And it's not just the interplay of the immune system and the nervous system.

And hormones play a massive role in disease.

I want to give a shout out to Riley Bouvet, who's a friend of mine at UCSF, who's done a lot of research in this area.

And a lot of the answers I'm providing right now come from some of her work.

So it's true that the onset of MS is three times more common in women than men.

And I'll tell you something really disturbing.

From the 60s to now, over the last several decades, the incidence of MS has been steadily climbing, but only in women, not in men.

And we don't know why.

And we're not exactly sure that it's related to hormones.

I know that sounds like goofy pants.

But yes, there's this sexual dimorphism where women are more likely to develop most autoimmune conditions compared to men.

But if you are a man with MS, it is true that you have a faster disease course.

Until about 50.

So let's unpack that.

Okay.

So it looks like estrogen has some protective effects in MS.

And a good example of that is what we see during pregnancy.

So when a woman is pregnant, the placenta makes insanely high levels of estriol, which is an estrogen, particularly in the second and third trimesters.