Buuuuuuut Gillie
I didn't know last year's problems was hayfever ***BG***
I prepared a bit and I may have spotted something new but where it takes me I'm not sure yet but ......

Three cheers for the SOED CD ROM.  Reading the pages I did find (blickie was not working last night) on feverfew I had to consult every other word at times.  But one article mentioned aspartame in the context of migrane.  **bingo**
aka aspartic acid  viz.
an acidic amino acid, COOH·CH2·CH(NH2)·COOH, which occurs in proteins and esp. in sugar cane, and is important in nitrogen metabolism in animals.  (= low calorie sweetener)
If this is the culprit then the results are very much OOOOH·OOOOH·OOOOH rather than COOH·CH2·COOH·CH2·COOH **notso BG**
Joyce (Johhny Collins' shipmate) reckons she sussed her migraine/Woodpecker link when she saw Bulmers no longer make cider. The legal definition is "milled from apples", any other adulterous substances have to be listed as incredients like "added sugars & sweeteners". Just for comparison; "shandy" is not beer, OK?
So why don't I drink only Tesco's own brand cider? I do 1 litre has been known to not affect me. But that is not predictable & the nectar is being marginalised, instead of easy to secrete cans, now only 2 litre slugs. I fear extinction in favour of a yet cheaper own brand (with added crappos). AND I don't somehow see yer average real ale pub charging me corkage on my cider.
Red wine has been a no no for years, and it gets worse during daylight hours (cue seratonin).
But is all this FOLK?  yes, yes, yes, cider is a traditional ENGLISH custom.  Yea, yea, so are hangovers!