How Not to Age: The Scientific Approach to Getting Healthier as You Get Older

by Michael Greger

MicroRNAs have been found circulating in at least twelve different human bodily fluids.7112 (When I read that, I had to stop and think, Wait. Can I even name a dozen bodily fluids?) We didn’t think this possible since we have enzymes that chop up any floating RNA outside our cells (as a precaution against viruses, which often come bearing RNA). It turns out they’re being transported in exosomes, tiny bubble-like vessels that pinch off from cells. We used to think these budding blebs were just a waste disposal device for the cells.7113 (Why do scientists seem to just jump to junk when they don’t understand something?) But, in 2007, we discovered that they were packed with microRNA.7114 Our cells were communicating with each other! In this way, a liver cell could send out microRNAs to regulate the genes in a lung cell, which could then regulate a brain cell, or vice versa. They could even talk to the next generation by depositing their microRNA load into a sperm or egg cell.