Eruvin 28: That Food Isn't Food, But Isn't That Food Food?

More on the food that is not just food, when it comes to establish an eruv. Greens, herbs, however they are identified by the Gemara's names (which Anne stumbles over): cress and sweet clover and more. Unused (for people) parts of wheat and unripe dates are not eligible for the eruv meal. But what about that sweet clover? It's not good for everyone, so how can it be eligible for this meal? The Gemara limits the statement to those who can eat it. Or maybe the clover is a different clover.... How would this food-that-isn't-food be translated into today's terms, when it comes to foods that aren't good for most people or for some people (allergies)? Similarly, should "hearts of palm," which in the Gemara is not considered food for an eruv meal, but today are eaten straight from the can... would we have other foods to add to the list of acceptable? (We know there are people who pasken these issues, and may well speak to them and circle back to this question).