I am equally confused. I think there is a dumb but somewhat worrying trend of people's political identity becoming so pervasive that it absorbs secondary and tertiary opinions about completely unrelated things.
Yes, a large segment of conservatives have taken the place that previously left-wing hippies occupied wrt skepticism of mainstream health advice, and seed oils is a major subject, I would say even iconic, with places like Reddit vehemently disagreeing and calling it anti-science or whatever. I agree that it's unfortunate, but currently this previously left-wing impulse to favor "natural", "unprocessed" products is predominantly found in right-wing circles.
Yeah this is a really weird shift that has happened in a relatively short time. In Sweden we have strange groups of nazis and hippies that you wouldn’t have thought would happen in a million years when I was a kid in the 80s/90s.