Researchers from the University of Ottawa, in Ontario focused their review on type 2 (AKA adult onset) diabetes.

Here’s a summary of the evidence for CAM therapies.


  • 2 of 3 studies report a decrease in fasting blood sugar.
  • Overall, there’s moderate evidence that cinnamon lowers blood sugar levels.
  • Its effect on A1c  (a measure of long term diabetes control) appears negligible, but long-term studies are needed to properly evaluate this effect.


  • A1c and fasting blood sugar were significantly reduced in a meta-analysis of all data.
  • There’s strong evidence that 200 to 1000 mcg of chromium picolinate daily improves diabetes control.
  • Based on its safety and potential cost-effectiveness, a definitive study is needed.
  • Biotin might enhance its effects, but this combination requires further study.


  • Fasting blood sugar was reduced in some less well-designed studies.
  • There is insufficient evidence to support its use in diabetes.


  • A non-significant reduction in A1c was reported in 1 of 3 studies.
  • Fasting blood sugar was lowered in 6 of 12 studies.
  • Evidence of short-term benefit is conflicting.
  • Fiber can be recommended based on its benefit for other cardiovascular risk factors, however.

Green tea

  • Fasting blood sugar was lowered in 1 of 3 studies.
  • There’s little evidence that green tea improves diabetes control.
  • Based on epidemiological evidence, further research is warranted.
  • Green tea can be recommended based on its potential for other health benefits.

Bitter melon

  • No benefit on A1c or fasting blood sugar in 2 small studies.
  • Current evidence doesn’t support its use.
  • Further studies in cultures where it has been used traditionally might be useful.


  • Fasting blood sugar was lowered in 1 of 3 studies.
  • Limited supporting evidence for diabetes, and high doses might be impractical for most patients.
  • Lipid-lowering benefits should be studied.


  • A1c levels were reduced in 2 small studies.
  • This A1c response warrants further study.

The bottom line?
Today, A1c is the best test of a treatment’s value for controlling diabetes. Future studies must account for the fact that it takes 3 months to see a change in A1c in response to any treatment.

Another recent reivew of herbals to treat diabetes is here.

6/14/09 16:55 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.