Detailed text transcripts for TV channel - KGO - 20120416:10:16:00
The very same thing. >> reporter: it's the most popular drug in the world. >> i need that little boost. >> reporter: it's everywhere from 320 milligrams in a starbucks cafe grande, about the max you should have in a day to energy drinks to sodas, now even inhalable. 100 milligrams in an instant. could that daily dose of caffeine be changing your brain? we turned to researchers at wake forest in north carolina where i underwent two mri brain scans. this first scan with no caffeine in my system. then i downed just one drink. now my second mri. this was my brain before caffeine. this was after. t...