and we're back with david sinclair professor of genetics at harvard medical school discussing whether external use. pipe dream or in knowledge so distant future so. david reprogramming our cells raising the levels of a and a d. plus molecule that will help reset the aging clock fine allowing a 60 year old to feel like 50 a 40 year old like 30 and cetera but is it possible to actually stop aging completely or only slow down. well if you ask me that just 2 years ago i would have said there's no way we can stop aging and we still don't know how to do that but we do know know how to reprogram cells to be very young again and take the age at least of a mouse was i all the way back from one year of age which is an old i back to being just a couple of months so now when you ask me that i have to say in theory it's possible that we could reset the body multiple times now we've research and i once but we're now testing if we could do it twice 3 times and maybe we can reset 100 times we don't know it just yet but that's a very exciting prospect that we will be able to have multiple resets withi