Botanical Sexism Cultivates Home-Grown Allergies

Most allergens are denatured by acid and enzymes in the stomach. Many food allergies, which typically are not the same kind of immunological reaction as seasonal allergies/allergic rhinitis, are caused more by the failure of epidermal barriers or acid attack than by mere exposure. don't become sensitized because you ate something so much as because your body allowed bits to get somewhere they are not allowed to be under any circumstances, which is why the outsized anaphylactic reaction food allergies often cause.

(...typically. In some cases it is cross reaction, where an antigen in food is too similar to some other antigen the body has previously identified as an invader. See for example the temporary meat allergy that can be caused by some Lone Star tick bites. And there are yet other causes of course...)

Seasonal allergies are usually mild because they are generally localized, peripheral, and provoked in tissues that are designed to give this response as a normal protective action.

(That is, your nose is correct to run or stuff in response to histamine release caused by pollen. Frankly, I feel some foreboding about what sequelae we will eventually discover to be caused by chronic H2 antagonist administration over decades, drugs like Claritin/Zyrtec that people are taking every day of their lives.)

So! While it is possible and some rare cross reactions have been observed (particularly in fruiting trees/eating fruits), as a general rule your seasonal allergies do not increase your food allergy risk.

Now, some people are at higher risk for both due to environmental or genetic circumstances. But there it is a prior immune dysfunction that caused both rather than one causing the other-- though it's an understandable intuition to connect them as your question does. Having one or the other makes it more likely you have both, but it one doesn't cause the other.

The article does address that notion -- trees are really good at capturing pollution, and a good amount of that pollution ends up in their fruit. Which sucks. I grew up foraging urban food, and I'll still pick and eat berries and stonefruits because they're too delicious to pass up, but it seems irresponsible for governments to promote such a thing.

I don't see any indication that the increase in litter would at all be of greater proportion than the decrease in pollen. Only that bit of pollen that gets blown to a neighboring female tree would get absorbed. Not even all of that, since presumably the majority would get blown off the tree. I can't see how any more than a single digit percent of the pollen would be captured, so people with allergies would still be affected.

The increase in litter would be significant if half the trees were female. On my college campus there were parts of the year where certain types of trees would drop seed pods and it littered the streets for the better part of a week. It'd take a significant amount of manpower to clean it up - probably a garbage-bag per tree - so we just left it outside and dealt with vegetation litter for a couple weeks.

Unless the article backs up the claim that the pollen reduction would be substantial and the increase in litter trivial it could still very well be that a mix of female and male plants does not prevent allergic reactions to such a degree that it's worth using a mix of plants.