The human physique replaces its personal cells recurrently. Scientists on the Weizmann Institute of Science in Rehovot, Israel, have lastly pinned down the velocity and extent of this “turnover.” About a 3rd of our physique mass is fluid exterior of our cells, resembling plasma, plus solids, such because the calcium scaffolding of bones. The remaining two thirds is made up of roughly 30 trillion human cells. About 72 p.c of these, by mass, are fats and muscle, which final a mean of 12 to 50 years, respectively. But we have now way more, tiny cells in our blood, which dwell solely three to 120 days, and lining our intestine, which usually dwell lower than per week. Those two teams subsequently make up the large majority of the turnover. About 330 billion cells are changed day by day, equal to about 1 p.c of all our cells. In 80 to 100 days, 30 trillion could have replenished—the equal of a brand new you.

Cellular Turnover In The Human Body

Credit: Jen Christiansen; Sources: “Revised Estimates for the Number of Human and Bacteria Cells in the Body,” by Ron Sender, Shai Fuchs and Ron Milo, in PLOS Biology, Vol. 14; August 2016 (complete cell information), and “The Distribution of Cellular Turnover in the Human Body,” by Ron Sender and Ron Milo, in Nature Medicine, Vol. 27; January 2021 (cell turnover information)