Probably the biggest kinds of bribery come in the form of trips, lunches, and conferences. The most disturbing part is that disclosure only makes matters worse.1
Some of the doctors I know are so overworked and feel so underappreciated that things like pens or mugs might do the trick.
This is ... depressing.
The realm of nutrition was of great interest to me at one stage. The more I dove into the literature, the more confused I became due to the contradicting publications. My Dad then gave me sound advice: “follow the money trail and the truth will be revealed".
Since then I always pay attention to who funds the studies I read. If the sponsor stands to benefit, I always take the results with a pinch of salt.