Looking at berberine in the lab and in life

The study had two parts:

• Test tube (in vitro)--which studied the effects of berberine in cells in laboratory petri dishes before and after 12 hours of treatment.
• Human (in vivo)--which studied the effects of berberine in people with type 2 diabetes for two months. First, 97 people were randomly assigned to receive either 1 gram of berberine, 1.5 grams of the glucose-lowering drug metformin, or 4 mg of another glucose-lowering drug called rosiglitazone per day. Second, 35 people with either chronic hepatitis B virus or hepatitis C virus and either type 2 diabetes or high fasting blood glucose were treated with 1 gram of berberine per day.

Test tubes show promising results

The in vitro research showed that treatment with berberine increased the number of insulin receptors on cells derived from a wide variety of human tissues, including pancreatic, immune, and connective tissue cells. They also found that cells were more responsive to insulin after being treated with berberine. These findings have important implications for people with type 2 diabetes, a chronic disease characterized by high blood levels of both insulin and glucose due to insulin resistance in the cells.

Berberine works as well as drug medicines

The human part of the study had several key findings:

• Compared with drug therapies, berberine was similarly effective.
• Berberine reduced blood levels of fasting glucose, insulin, triglycerides, and a marker of long-term blood sugar control (HbA1C, or hemoglobin A1C).
• Some of the berberine-treated people underwent special testing which revealed that the percentage of a certain type of white blood cell having insulin receptors had increased during the study.
• People with the hepatitis B and C viruses also benefited from berberine: fasting blood glucose, triglycerides, and liver enzyme levels were all reduced after treatment.

"Our results confirmed that berberine increases insulin receptors in humans and that this is associated with its glucose-lowering effect," said study co-author Jian-Dong Jiang at the Chinese Academy of Medical Sciences in Beijing. " We believe that berberine, which has a different mechanism than other glucose-lowering drugs, is an ideal medicine for type 2 diabetes."

Other natural therapies for diabetes

The best medicine for people with type 2 diabetes is a healthy diet and regular exercise. The results from this study suggest that a gram of berberine per day might help get blood sugar under control. Bear in mind that any supplement may interact with glucose-lowering drugs and could cause low blood sugar (hypoglycemia). If you have diabetes, check with your doctor or other healthcare provider before adding supplements to your program, including these that have also been shown to support diabetes management:

• Chromium--as much as 500 mcg twice per day is often recommended to improve insulin sensitivity and reduce blood glucose levels.
• Alpha-lipoic acid--this antioxidant appears to improve insulin sensitivity and prevent complications such as neuropathy and kidney damage.
• Fenugreek--the powder from fenugreek seeds is rich in fibers that slow carbohydrate metabolism and, when taken with meals, has been shown to reduce the after-eating rise in blood glucose levels.
• Gymnema--although the evidence is still only preliminary, gymnema might increase insulin production by the pancreas and improve the cells' responsiveness to insulin.

(Metabolism 2010;59:285-92)