"If you say the trans-fat found in butter are harmful, the burden of proof is on you."

[teo123]

So, I've once again tried to convince some Flat-Earthers to go vegan. And MaNaeSWolf claimed that only the trans-fats found in margarine are harmful, while the trans-fats found in butter are healthy. I said that since most nutritionists think all trans-fats are harmful, one who claims otherwise has a burden of proof he can hardly meet. Then he responded that since, it's supposedly harder to prove a thing is harmless than to prove it's harmful, the burden of proof is one claiming a thing is harmful. Then I responded with:

Really? Well, let's say you walk into a forest and are feeling hungry. Would you pick up a random plant, assume it's safe to eat and eat it, just because, as far as you know, it hasn't been proven to be unsafe? Obviously, the burden of proof is on one who claims it's safe.
And this situation is even worse than that. It's more like if you weren't sure if that plant was safe to eat, but you knew a plant closely related to it was deadly poisonous. So, the burden of proof is even higher.
But it's even worse than that. It's that your textbook is telling you that plant, as well as plants related to it, are deadly poisonous, and somebody claims that that particular plant actually isn't. That's now a very high burden of proof.

Do you think that's a good response? Do you have a better idea?

[ExoticParallel]

In my opinion, there's no reason to engage with flat earthers on a topic like medicine or health. but if you are sure I recommend going to Dr Avi's discord server (not sure if I can post links but its called Study Archives" and asking him this)

[brimstoneSalad]

That's a fair response, though you might add to it: Also, there's a plant right next to it that everybody already agrees is safe and the only reason you won't just eat that one instead is some bizarre principle of insisting you should be able to eat everything despite there being both plenty of food and variety available without this likely poisonous option.