That’s when women are supposed to start getting mammograms and men are supposed to start paying a bit more attention to their prostates. Instead, Topol said, there appears to be a correlation between having a healthy immune system and aging healthily. For the average American, Topol said, health span is about 63 to 65 years. “Health span should be extended as close as we can to lifespan, and I think we can do it,” Topol told Upson. We never had biomarkers like p-tau217, which tells us about our risk of Alzheimer's 10, 15, even 20 years in advance.