I wouldn't want to do a whole teaspoon or capsule full as I like to go slowly with things like that. But I might try making a few Indian style dishes even though those are not my favorite flavors.
Maybe 15 years ago, I first noticed an effect from some curry I made: it blocked my typical flare-up of symptoms after a meal. That was probably only a fraction of a tsp of cumin. When I tried a full tsp, I got a temporary remission. Sadly, it stopped working after taking it for a week or so. It wasn't until a year or two ago that I noticed that cumin blocked my PEM.
As a PEM blocker, less than a level tsp of ground cumin wasn't fully effective, so I stayed with a level tsp. Larger amounts weren't any more effective (the lvl tsp was 100% effective), and the duration only increased slightly, so it wasn't worth it.
We've been explicity warned about not using spice rack condiments for our health.
I've never encountered that warning. Maybe that's marketing from the health food industry, since packaging the same ingredient as a 'health product' is more profitable?
but what is exactly written that leads you to believe the ordinary spice rack cumin is fine?
Nothing written. I certainly never read anything about using cumin for ME. The ordinary cheap no-name cumin is what worked for me, so there's no question about it's effectiveness.
Main difference, I think, is the freshness of the spice.
I bought a big bag of seeds from a bulk bin 15+ years ago, when I found that it gave me remission, and most of it just sat on the shelf after it stopped having that effect. After 15+ years, it was significantly (~50% IIRC) less effective, but not completely ineffective, so I wouldn't be too worried about freshness.
I see some of us are cooking the cumin and some not. Anyone with thoughts about this?
I found it as effective cooked in curry as uncooked. Maybe cooking methods at higher temperature (dry roasting) or cooking it wet for several hours might diminish its effectiveness.