Reminds me of a story about somebody who got sick at a sports event in the stadium, and they announced that they thought it was food poisoning from some food or beverage they purchased at the stadium.
Then tons of people also got sick.
Then they announced that all the food and beverages were fine (no botulism) and all the people who thought they were sick suddenly were better. It was the placebo effect. People thought they were sick because they ate food they thought became bad. When they learned the food was okay and they had no reason to be sick, they suddenly "healed" and were fine.