Circulating levels of white blood cells (WBCs) are one of the 10 variables used to quantify biological age with PhenoAge ( The reference range for WBCs is 4.5 – 11 *10^9 cells/L, but within that range, what’s optimal? Several studies have reported that WBCs greater than 5 are associated with an […]

In an earlier post, based on data from the Baltimore Longitidunal Study on Aging (BLSA), I suggested that total white blood cell (WBCs) counts between 3500 to 6000 cells per microliter of blood may be optimal for reducing disease risk and for maximizing longevity ( However, within WBCs, neutrophils increase, […]