Early research indicated glucosamine might not be safe for diabetics, but more recent and better quality studies show the supplement is likely safe for most people with this condition, according to MedlinePlus, a website provided by the National Library of Medicine. Consult your doctor before taking glucosamine for painful joints, particularly if you have a health disorder such as diabetes or are taking medication.
Benefits
Glucosamine sulfate occurs naturally in the fluid around joints. The glucosamine in dietary supplements commonly comes from shellfish shells, although some manufacturers use synthetic glucosamine. MedlinePlus rates glucosamine as "likely effective" for osteoarthritis. Evidence indicates glucosamine may help reduce the pain of knee osteoarthritis at a similar level as the pain medications acetaminophen, ibuprofen and piroxicam. Glucosamine takes longer to work, however, generally providing some relief within four to eight weeks, while the medications decrease pain within about two weeks. Glucosamine may also be helpful for osteoarthritis of the hip and spine, and when taken long-term, it may slow osteoarthritis-related breakdown of joints.
Safety
Early research with glucosamine involved animals given high intravenous doses, according to an article published in the December 2006 issue of the "Journal of Family Practice." The early research suggested that glucosamine might raise blood sugar in diabetic patients, explains MedlinePlus, while noting that more recent clinical studies indicate the supplement does not affect blood sugar control in people with Type 2 diabetes. Although glucosamine appears to be safe for most people with diabetes, monitor your blood sugar closely while using this supplement if you have this health disorder.
Considerations
Many joint supplements contain both glucosamine and chondroitin. The "Journal of Family Practice" article notes that supplementing with 1,500 mg of glucosamine and 1,200 mg of chondroitin per day does not have a negative effect on short-term blood sugar control in people whose diabetes is well-controlled. It also does not have a negative impact on blood sugar in people who do not have diabetes or glucose intolerance, commonly called prediabetes. However, glucosamine may worsen glucose intolerance in people with undiagnosed prediabetes or uncontrolled diabetes. Uncontrolled blood sugar appears to be the one case in which diabetics shouldn't take glucosamine.
Glucosamine and Medication
Early research also raised concerns that glucosamine could reduce the effectiveness of diabetes medication, but since the supplement probably does not increase blood sugar, it also probably does not interfere with diabetes medications, according to MedlinePlus. Some medications used for Type 2 diabetes include glimepiride, glyburide and metformin.
