How about this to confound your statistics.
I grew up in the 1950's my Mother prepared everything we ate except for special treats very rarely when we were allowed sixpence to buy our own lunches at the local dairy. We live in NZ so no such thing as school dinners and the dairy was a shop which sold dairy foods, of course, plus a few baked goods and lots of sweets. A cream donut or a meat pie was more or less all we had to choose from. I remember Chicken Noodle Soup becoming available and we thought it was the worst thing we had ever tasted.
There was no Wifi, cellular telephones or other greeblies in the air. Most of us didn't even have a landline telephone, communications between kids were plans made on the way home after school and bikes were our mainstay. I was sent down the road to the public call box to phone Dad to ask what time he would be home for dinner.
So in spite of all this I developed my first symptoms of Sclero when I was about 14 or 15. Terrible stomach pains which were explained away as colic once a Barium Swallow had shown nothing. By the time I was 22 I had Raynaud's and stomach involvement.
Nothing amongst all the things suggested or listed anywhere as a cause for Sclero had ever come into my life. I can't even blame starting to travel outside NZ when I was 20 because I already had the stomach stuff.
I realise that maybe some instances might be traced back to environmental causes but for me at least I can only blame a genetic pre-disposition.
Best wishes from the upside down side of the world,