Every year families fill their homes with company and get after a big ole turkey. Then, ritualistically we find the nearest couch or bed and snooze for hours. It's the turkey's fault right? Nope. It's supposedly a myth. The component in turkey that is blamed for drowsiness is also found in other meats and cheeses...in the same proportional quantities.
However, there are factors that make us seek out that resting ground. A huge meal among others causes sleepiness.
Not surprisingly, I will still use the excuse and blame it on the turkey when I have the choice to clean up the kitchen or obey they driving desire to nap. "Well, that darn turkey made me sleepy again. I think I'll have to lay down and sleep it off."