The biggest threat is high-fructose corn syrup (HFCS) but even brown sugar is highly refined white sugar with some of the removed molasses added back in for flavor and color. They are the source of major insulin spikes and feed the growth of cancer cells. Since the majority of the sugar supply in the U.S. is made using genetically modified (GMO) sugar beets, a healthier option is organic honey, coconut sugar, or maple sugar. That is true, it may not be that the sugar itself is causing the growth of cancer cells. But because it is genetically modified, it is more prone to let the cancer cells grow.