would be reasonable for some company or academic research lab to invest the resources to take a closer look

If I was suffering from migraines, this is the kind of anecdote I'd pay attention to. Like you said, low cost and low risk, no clear scam incentive

The search for such compounds is often referred to as natural products research and has historically played an important role in the development of new drugs. This anecdote is like a sample size = 1 study and could just be the placebo effect, but if a lot of other people try it and benefit then it

water, compared with other foods, that also has some therapeutic effect for some migraine sufferers

I'm not an expert in migraines, and I didn't read the original post, but I did a PhD measuring the chemical composition of biological samples looking for bioactive compounds and in my view it is absolutely possible that there is a chemical that is notably higher in not-too-old sardines canned in