I told him that's not how digestion works and that the cartridge would pass through his body within a day or two, but he argued that since our bodies extract nutrients from food there would be some type of infusion taking place, where he would absorb some of the coding from the game into fat reserves or bone marrow or something else.
Tell him to read up on how ROMs work. The short of it is that there are many pins on a ROM-chip. Some are address pins, and some are data out pins. You put a voltage on some pins to indicate which address line you want, then the chip outputs 1s and 0s on all the output chips to output that line of memory. So.. Unless his body knows how to connect to the pins and then read it, it's.. well.. yeah.. a fucking stupid idea.
... he said that since the liver and stomach are so close together, it would increase the chances of Zelda code spreading to other areas of his body if pieces of it travel thesame route as the alcohol does for digestion.
You know what, I'm pretty sure the transportation cells that move alcohol from the intestines to the liver are set to also pick up code. But hey, I'm just a programmer, not a biochemist. I also would dispute that either of the enzymes aldehyde dehydrogenase, alcohol dehydrogenase, or catalase are involved in breaking down a ROM and converting the code to be transported through the brain. That's given that code even can pass through the brain blood barrier.
Has anybody run into DS or 3DS games being swallowed before, be it by a sibling or a pet or something? Is there any science I can point him to in an attempt to dissuade him from doing this?
If you need science to tell you this is a bad idea, I don't know what to tell you. I'd cheer him on, but sadly the cartridge won't fit through his esophagus.