Blood age

Blood age uses PhenoAge, a model published in 2018. Researchers took about 10,000 American adults who'd had a routine blood test, followed them for over two decades, and asked which markers best told apart people who stayed well from those who didn't. Nine made the cut, plus age.

The nine come from three common tests. A metabolic panel gives albumin, creatinine, glucose and alkaline phosphatase. A blood count with differential gives white cells, the share of them that are lymphocytes, red cell size (MCV) and how much red cells vary in size (RDW). A high-sensitivity CRP test gives inflammation. Most labs run all three from one draw.

The model turns those numbers into the age at which they'd be expected. In the people it was built on, each year of Blood age above your real age came with about 9% higher mortality over the follow-up, after accounting for real age. A second study found the same pattern across groups by sex, race and income.

Blood age is an estimate, not a diagnosis. One test is a snapshot: a cold, a hard workout the day before or a big dinner can shift CRP, white cells or glucose. That's why Ageon keeps it separate from Ageon Age, which moves with your week. Compare tests taken the same way, ideally fasting, in the morning and when you're well.

What tends to move it is familiar. Inflammation and blood sugar carry the most weight, and both respond to the basics. In trials, regular exercise lowered CRP, more so when it also brought weight down. Sleep, alcohol and smoking all show up in these markers too. Give a change a few months before you retest, since most of these markers move slowly.

A value outside its usual range is worth a conversation with your doctor, whatever your Blood age says.