Now that the new honey season soon begins, I would like to share some thought about food quality and why it is important to not always buy the cheapest things in your life. We have only one body and we shouldn't think of it as a furnace which will burn everything down to trash.
HMF (HydroxyMethylFurfuraldehyde) is used as an indicator of heat and storage changes in honey.
HMF levels over 40mg/kg in honey (which show heat treatment or bad storage at high temperatures, the quality is thought of as unsuitable. Many sugar type products (e.g. Golden Syrup, Molasses etc.) have levels of HMF that are 10-100 times that of honey. Many food items sweetened with high fructose corn syrups, e.g. carbonated soft drinks, can have levels of HMF between 100 and 1,000 mg/kg.
Although this is played down as harmless, a journal of the European Food Safety Authority sees this differently:
In addition to the above mentioned pathways, 5-hydroxymethylfurfuraldehyde canbe bioactivated to 5-[(sulfoxy)methyl] furfural, through sulfonation of its allylic hydroxyl functional group, catalyzed by sulfotransferases. The resulting ester has been demonstrated to induce genotoxic effects.The EFSA Journal (2005) 215
Therefore heat treated honey, most common in super cheap discounter quality, but also products containing corn syrup or glucose syrup (most evident in all highly processed baked goods, sweets, and soft drinks) don't do your health any good. Therefore, buy less of these things, save your money and buy real good quality as a treat now and then. And it also helps keeping you in shape :)