Where does disease really start?

We've all heard this adage that all disease starts in the gut. And while that may have been true many, many years ago, I believe this day and age, many diseases actually start because of our mindset and because of our environment. It's our environment that drops us cues in order to think that poisonous foods are actually healthy for us. It's our environment and commercials and billboards and all this stuff that we see, but that convinces us it's okay to eat food that destroys our body. And it's our mind that is then brainwashed to believe that this is true and then allows us and enables us to actually eat that food which is poisoning us. So disease can manifest from the gut. But I believe if we trace it back to where it originated, it's probably in the mind, which is influenced by the environment.