Fructose is often recommended for, and consumed by, people with diabetes mellitus or hypoglycemia, because it has a very low glycemic index (GI) relative to cane sugar (sucrose). However, this benefit is tempered by concern that fructose may have an adverse effect on plasma lipid and uric acid levels, and the resulting higher blood levels of fructose can be damaging to proteins (see below). The low GI is due to the unique and lengthy metabolic pathway of fructose, which involves phosphorylation and a multi-step enzymatic process in the liver.