After reading about the health benefits of palm sugar with its low GI rating of 35, I thought it might be a good replacement for granulated sugar for baking .  I tried it, and was quite pleased with its results. But now, after some discussion with friends , the question arises as to why palm sugar had a lower GI as compared to refined sugar especially when both sugar contained comparable amount of fructose and glucose.

Sugar palm trees are a group of palm trees from which sugars or syrups are derived, and not a particular kind of palm tree. Palm sugar trees include Wild Date Palm, Coconut Palm (Cocos Nuciferas), Ceylon Sugar Palm, Palmyra Palm, Aren Palm and Nypa Palm.

Any palm sugars made from any of these trees are close to impossible to differentiate by sight or feel. A laboratory analysis could determine the difference, but it's not like your average  household has one in their  pantry. This makes shopping for palm sugar confusing when all that is marked on the packages is "Palm Sugars".

One thing you need to be aware of is the prevalence of palm sugars disguised as sugar coming from coconuts. There are a number of palm trees from which palm sugar is made from and only those from coco nuciferas has been studied and proven to have low GI properties. You will have to check web sources for any products you might consider buying,  I have checked out a few suppliers and Big Tree Farms Coconut Palm Sugar  seems to make a quality product.   

Coconut palm sugar is low glycemic index of 35 which is slowly absorbed by the body, which doesn't induce the rise of blood sugar , a very important factor for diabetes management according to the Philippine Food and Nutrition Research Institute ,through the research efforts of the Philippine Coconut Authority, are specific to coconut trees (cocos nuciferas.)

Contrary to common understanding, the relationship between sweeteners and glycemic response is more complicated than simply, "sugar is high glycemic".  The complication lies in the chemical composition of the sweetener. Yes, cane sugar rates as a 65 on the glycemic index and is therefore considered high glycemic, but that is 100% sucrose (like refined cane sugar or table sugar).

Coconut Palm Sugar alternatively is an unrefined sweetener made up of a majority of sucrose, but also having percentages of fructose, glucose and most importantly perhaps, significant nutrients, vitamins and 12 important amino acids. These "other" materials, and especially the amino acids are thought to act as a buffer to the sucrose component of the coconut sugar, thereby slowing the speed by which the sugars are absorbed into the blood stream. This slowing of the absorption process is what causes a slow down in our glycemic response to coconut sugar and therefore the lower glycemic index rating.

Palm sugar contains substantially more phosphorus , potassium and chlorine than refined white sugar,  and I am wondering if this could this be a contributing factor in its low GI rating.