Spinach? Why didn't I think of it before?!?

This is a rant.
I just got on my bus. I was sitting on a bench at the bus loop at school, and a grizzled 40something man in a wheelchair rolled up. He asked if I minded if he sat down and I said no.
Then he added, "I smoke."

Immediately I replied, "Then I do mind, because I have asthma." I was firm, but not judgmental about his life choices, though I was curious why he was in a wheelchair when he so easily got up to move to the bench.
I saw a bus pull up and said, "Never mind; you sit down--that's my bus anyway."

Then he proceeded to tell me I should get rid of my asthma! "Eat some spinach," he said. Apparently this is how to free myself of the wheezing and coughing and general discomfort of trouble breathing, particularly when I'm exposed to smoke, dust, animals and mold.

Oooh, that annoyed me. "I can't get rid of it," I told him. "I've had it since I was a baby. My grampa still has it and he's in his 70s. It doesn't go away."

I had gotten up to go to my bus--which mercifully kept its motor running and left in under a minute--and I heard him say, "And put some meat on your bones!"

Great. So now he's staring at my ass under my backpack and telling me how to cope with my lifelong affliction! I am so sick of people who think they know what it's like living with asthma. "Take a pill," they say. "Get allergy shots."

No, thanks. I don't want to put any more chemicals in my body than I already do with my two separate inhalers (which I take as infrequently as possible). And I certainly don't need someone who smokes telling me to improve my health by putting on weight and eating more spinach. Anyway, aren't the two mutually exclusive?

Arrrgghh!