Apios Americana makes some people sick?

Has anyone experienced this?

Orion Magazine

"It was just as our friend Dave Varney had said: Apios americana is a permaculture plant. But Sam wanted to talk about something else.

“I have to tell you, since I’ve been feeding people hopniss all these years, I’ve found out some of them will get violently ill after eating it.” It had never happened the first time someone tried it, he said, but it could happen the second time or even after many years of eating it. “Maybe you need to build up a certain dose of the protein. Maybe there’s more of this allergen in larger tubers. Or it might have to do with the growing conditions.” He estimated that as many as 5 percent of Apios americana eaters would be made sick at some point and, once they reacted, would become ill with every subsequent bite. “That’s the only thorn on this rose. Otherwise, it would be a perfect food.” "

It sounds hard to accept its a perfect food, if it makes you sick.
Its a bit like saying if you walk along a road the path is clearer, but you may get hit by a car whilst doing it.
But its the perfect place to walk.

That's sometimes how allergies work.