I seriously doubt that anything sold as pure cinnamon would be adulterated by any spice manufacturer. In any case, it happens to be one of the cheaper spices. However, as with any agricultural product, there is always a risk of mold, etc. --but AFAIK no more than other spices. However, it is not surprising that humans would react to spices. Plants produce aromatic compounds for their own ends--often to deter pests. I've used cinnamon to repel an invasion of ants--when cayenne pepper failed to deter them. You can check your brown sugar reaction by seeing if molasses bothers you. It contains the contaminants that have to be cleaned out of the brown sugar to turn it into table sugar. If molasses doesn't bother you then real brown sugar--the stuff that sets up like a lump of concrete--should not. However, be careful of the "pourable" stuff which needs something to increase flowability--but the additives used should be on the food label. It's possible to make your own "brown sugar" by adding a bit of molasses (preferably the dark flavorful kind) to white table sugar. Barbara Wise CHOice lowcarb, dairy-free frozen desserts ThickenThin lowcarb thickeners for shakes and sauces Now available at http://ExpertFoods.com