Pharmacy U

What about cinnamon, chromium and ginseng for patients with Type 2 diabetes?

PB_PBQ_Colour Palette_2016

Many people with diabetes choose to use complementary and alternative medicines (CAM).


By Shelley Diamond, BScPhm

Illustration by Martin Bregman


Here we examine three common complementary agents – cinnamon, chromium and ginseng.




Cassia cinnamon has been used for diabetes, but the evidence regarding its effectiveness is contradictory. Doses studied have ranged from 120mg to 6 grams daily for up to four months. An updated systematic review and meta-analysis of randomized controlled trials evaluating cinnamon’s effects showed a statistically significant decrease in fasting plasma glucose, total cholesterol, LDL-C and triglycerides, and increased levels of HDL-C. No significant effects on HbA1C levels were found.


Tell your patients:

  • Cassia cinnamon may be of benefit for managing type 2 diabetes, but the optimal dose and duration of treatment are not yet known.
  • It’s generally well-tolerated with no significant side effects reported in clinical trials.
  • Caution use of high doses in those with pre-existing liver disease since cassia cinnamon contains coumarin, shown to cause hepatotoxicity in animals.




Chromium is an essential trace mineral which is important for processing carbohydrates and also increases insulin sensitivity. Chromium picolinate has been shown to decrease fasting blood glucose but does not reduce HbA1C.


Tell your patients:

  • There is insufficient evidence in the literature to make a definitive conclusion on the effects of chromium on glucose control – its effect may be highly variable because of individual reactions to the mineral.
  • Studies show that the form of chromium influences its effects. Chromium picolinate appears to provide greater efficacy likely because of its increased absorption and bioavailability.
  • Chromium has a favourable safety profile when used at typical daily doses of 200-400 mcg.




Traditional Chinese medicine has used for thousands of years. Below are the main types of ginseng that have been used.


Botanical name Common name
Panax ginseng Asian (Chinese or Korean) ginseng
Panax japonicas Japanese ginseng
Panax quinquefolius American ginseng


3g American ginseng taken up to two hours before a meal can significantly reduce postprandial glucose levels in patients with type 2 diabetes. Another study has shown that 100-200 mg daily for eight weeks also reduces fasting blood glucose levels in patients with type 2 diabetes. Other studies have evaluated ginseng extract favourably, however, the species of ginseng was not specified.


Tell your patients:

  • Depending on the preparation of American ginseng chosen, the glucose lowering effect may vary because of variations in the concentration of ginsenosides.
  • Take with food.
  • Caution in people with hypertension.
  • Avoid using during pregnancy or breastfeeding, or in people with schizophrenia or bipolar disorder, breast cancer or other hormone-sensitive conditions.
  • Stop ginseng use at least seven days before surgery because of its glucose-lowering and anticoagulant effects.


Whatever supplement, dose adjustments to diabetes medications may be necessary due to their potential glucose lowering effects. Remain open-minded and non-judgmental when counselling patients using CAM, and proactively query them on their use of these agents to support their diabetes management.





  1. Natural Medicines Comprehensive Database
  2. NIH Office of Dietary Supplements
  3. DiNardo MM et al. Complementary and alternative medicine in diabetes care. Curr Diab Rep 2012; 12(6):749-61.
  4. Allen RW et al. Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis. Ann Fam Med. 2013; 11(5):452-9
  5. Yin RV, Phung OJ. Effect of chromium supplementation on glycated haemoglobin and fasting plasma glucose in patients with diabetes mellitus. Nutr J 2015 14:14.
  6. Qi-feng G, et al. The efficacy of ginseng-related therapies in type 2 diabetes mellitus. Medicine. 2016;95(6):e2584.