I'm thinking/hoping that people would know if they would be at risk for Favism, before growing or eating fava beans.
A reasonable precaution, before eating favas for the first time. It is a genetic weakness, mostly in people of Mediterranean or Middle Eastern ancestry (and apparently some of India descent) so something your parents or other family might know. A lab or doctor can test for it, but I have no idea how much the test would cost, or where to get it. If I were to eat favas, I would probably be the first in my family to do so (maybe ever). To be honest, I'm not even sure I will like them yet!
I would grow favas for seed regardless, as a service to those who might want to grow them... and because my bean curiosity demands it.
@Jack Holloway , you brought up an important issue, about growing unfamiliar legumes for the first time. Many of the world's cultivated legumes (or pulses) require special precautions to be consumed, which we sometimes take for granted because their proper preparation is part of our culture. For example, we in the U.S. cook the toxicity out of limas & dry beans perhaps less because we know of the toxins, than because we have always done so. The danger is when something is grown outside of the culture(s) which are familiar with it. I was showing a friend who spends a lot of time in Europe my garden, and showed them a large runner bean seed... which they started peeling to eat raw, as they said they had done with favas. I had to explain to them that raw Phaseolus beans could make them ill.
The grass peas (Lathyrus sativus) which I tried to grow for the first time last year (and which failed) have their own eponymous disease, lathyrism, which can be caused by consumption over time.