[ laughter ] [cheers and applause] side effects of vacsa-ternity include: abdominal foosball, elbow-bagginsand the humpty hump. a. [ laughter ] of course, if you use vacsa-ternity and live forever, you're going to want a strong body and a sharp mind! so, our next subject: aging. >> old! [ laughter ] >> stephen: that is strangely familiar. [ laughter ] man has long searched for the fountain of youth. we've tried it all: potions, plastic surgery, watching "benjamin button" while standing next to a microwave. it's gotta do something. [ laughter ] well, there's new hope that we can turn back the clock. >> scientists now think that they found how to reverse effects of aging. according to stanford university, if you get a blood transfusion from someone younger it could help improve learning and memory. >> stephen: yes, the blood of the young can help improve your memory, although you will remember only xbox cheat codes and taylor swift's ex-boyfriends. [ laughter ] [cheers and applause] now, the study's author, doctor saul villeda, connected the circulatory systems of old and young mice so their