I can't download the paper. I'm sorry, but reading the abstract, I don't see how that paper supports your argument.

"Highlights

• Chronic Pb exposure could result in a lower weight gain in rats and a higher Pb content in the brain of model rats.

• Pb exposure reduced activities of key enzymes of glucose metabolism in the brain.

• Pb exposure could disrupt the insulin signaling pathway in the hippocampus of rats."