Bruce Lanphear

That led to a second study that was just published last year, and it was focused on people who had diabetes.

They saw some benefit, but it wasn't significant.

So whether that's because there wasn't enough variability in exposure, it's not entirely clear.

But we've seen this with lead and IQ deficits in kids, where we can show that we can reduce blood lead levels.

But ultimately, what tends to happen is once you've taken lead out of the blood, some of it's released again from the bone, but you still have all that lead in the bone that's there.

Yeah.

You get some of it out, but you're not going to get the bulk of it out.

Yeah, this was really, a lot of the seminal work in this area was done by Ellen Silbergeld, who's a brilliant and somewhat mercurial toxicologist.

And Ellen, for years, I focused on childhood lead exposure.

And for years, Ellen would tell me, almost admonish me for not studying adults.

And because she had found back in 1988 that as women go into menopause, their blood lead levels spike, increase by about 30%.

And that's where most of our lead is stored, is in our bone.

And so as I was thinking about this, it all became clear because blood lead levels in boys and girls is about the same.

It's comparable up until menarche.

And then girls, young women's blood leads fall by about 20%.

And they stay 20% lower throughout the reproductive years until menopause.

And especially during those first few years around menopause, perimenopause, you see fairly striking increases in the weakening of the bone and in blood lead levels.

So that might very well help to explain why estrogen is protective.

Because what happens is throughout that reproductive life, women are losing a little bit of lead every month.

And estrogen is at its lowest during that time of menses.