Each university has a slightly different policy in terms of what shows up on your official transcripts. The only way adcoms would know that you switched your major is if it shows up on your transcript. Even if it does show up, adcoms probably don't care that much but since I don't serve on an adcom, that's just an assumption. If the adcoms knew that you switched, they might ask you about it in which case you could tell them a story about how you learned something. I don't think it's that unusual for people to change their interests. It seems to happen in med school all the time in pursuit of specialties.
That being said, I would go ahead and switch if it is something that truly interests you.
