Alternative and Complementary Medicine for Diabetes

December 26, 2015

Although information on the safety and efficacy of CAM is a murky area full of conflicting, inconclusive evidence, certain types of CAM do hold promise, and may deserve consideration.

Between 17-73% of patients may use complementary and alternative medicine (CAM) at some point to help manage their diabetes.1 CAM offers the promise of treatment without the side effects of conventional medication. Some patients may also feel that CAM remedies are closer to nature, and for that reason somehow better than conventional medicine.

The risk is that some types of CAM have little or no efficacy, while others may do harm or interact with other medications. Information on the safety and efficacy of CAM is a murky area full of conflicting, inconclusive evidence. On the other hand, certain types of CAM do hold promise, and may deserve consideration.   

Herbal Supplements and Micronutrients

Hundreds of supplements are used in CAM for treating diabetes, but supporting evidence suffers from methodological issues: studies with small numbers, too short duration, and/or lack of an appropriate comparator. Nevertheless, many substances have mechanisms of action suggestive of antihyperglycemic effects.

Perhaps the most promising supplement is chromium. Deficiency of this trace mineral causes reversible diabetes. Chromium is a cofactor in insulin regulation and plays a major role insulin sensitivity. Though it may be the only CAM that has level 1 evidence supporting its role in diabetes management, large-scale clinical trials are needed before it can be recommended.2 Chromium supplements may cause stomach pain and bloating. Kidney damage, muscular problems, and skin reactions have also been reported.3

Other key players include:

• Fiber: No consistent evidence that a high fiber diet improves HbA1c, though it may help control cardiovascular risk factors.2

• Gymnema sylvestre: Known as gurmar (sugar-destroyer) in Hindi, this supplement is used in Ayurvedic medicine for treating diabetes, cholesterol, and obesity. Possibly improves HbA1c, but evidence is insufficient.2

• Bitter melon: Some human clinical trials support its glucose-lowering effects, but there is not enough evidence to support its use in diabetes. The active ingredients are thought to stimulate insulin release, which may be less desirable than improving insulin sensitivity.2

• Aloe vera: Human studies suggest a glucose- and triglyceride-lowering effect; has laxative properties, which could potentially lead to electrolyte imbalance and increased arrhythmia risk.4

• Fenugreek: Used in Ayurvedic medicine, but there is limited evidence to support its use in diabetes. The active ingredient is thought to increase insulin secretion. Contraindicated in pregnancy and with glucose-lowering drugs, anticoagulants, MOAs.2

• Cinnamon: Used for thousands of years to control diabetes. The extract seems to activate the insulin receptor, and a moderate amount evidence suggest a blood glucose lowering effect. Little evidence supports an effect on A1c.2 May interact with blood thinners, increase bleeding time, and worse liver disease.3

Micronutrients and Others:

• Vanadium: Used to control diabetes before insulin and may have insulinomimetic properties that are poorly understood. Due to potential adverse renal effects, it should probably be avoided.2

• Omega-3s: Little evidence to support its role in diabetes control. A systematic review showed that omega-3s improved triglycerides but had no effect on fasting blood sugar, HbA1c, or other lipids in patients with T2DM; side effects include GI discomfort and increased bleeding time.5

• Vitamin D: Some studies suggest vitamin D may decrease the risk of developing diabetes, though evidence is conflicting; no specific recommendations exist about appropriate vitamin D levels and supplementation for T2DM.

Other types of CAM for diabetes include mind-body therapies like acupuncture, yoga, dance, tai chi, qigong, as well as physical interventions like resistance, balance, and flexibility training.  Relaxation techniques include meditation, biofeedback, and hydrotherapy (hot-tub therapy).

The idea is that these techniques decrease stress, improving mood and sleep as well as quieting an overactive sympathetic nervous system, which may help decrease chronic inflammation.

Perhaps one of the most widely studied of these mind-body techniques is yoga. It is commonly used in India for managing diabetes, and Indian guidelines recommend yoga for diabetes control.

Yet the evidence is still conflicting. One large randomized controlled trial conducted at the University of California San Francisco and San Diego compared 48 weeks of restorative yoga vs stretching in 180 adults with metabolic syndrome. Results showed that yoga was “marginally” better for controlling fasting glucose, but it had no effect on HbA1c.6

One of the issues in that study may have been the use of restorative rather than more active forms of yoga. Nevertheless, even if yoga may not help with blood glucose control, it may help decrease diabetic complications. One randomized controlled trial in Hong Kong randomized 182 adults with metabolic syndrome to yoga (Hatha, breathing, relaxation) vs no yoga. At the end of one year, yoga participants had significantly decreased waist circumference, and results showed a trend towards decreased systolic blood pressure.7

One of the most recent CAMs on the scene is laughter therapy, popular in some parts of Asia like Japan and Korea. Although research is very preliminary, some researchers hypothesize that laughter may up-regulate genes involved in immune activity and modulate natural killer cell activity, which may improve blood glucose levels.8,9

If that sounds like a stretch, it may be reassuring that at least some forms of CAM may do no harm. At the end of the day, a good belly laugh never hurt anyone.

Take-home Points

• Evidence for the efficacy and safety of CAM is hindered by methodological flaws: studies with small numbers, too short duration, and/or lack of an appropriate comparator. 

• Hundreds of herbal and micronutrients supplements exist for the management of diabetes, with the strongest evidence supporting chromium, but large-scale trials are needed.

• A broad range of mind-body therapies exist for managing diabetes; yoga is the most extensively researched, though results conflict about its effect on glycemic control.

• Laughter therapy is the newest player on the scene.




1. Chang H, et al. Use of complementary and alternative medicine among people living with diabetes: literature review. J Adv Nurs. 2007;58:307-319.

2. Nahas R, Moher M. Complementary and alternative medicine for the treatment of type 2 diabetes. Canadian Fam Phys. 2009;55:591-596.

3. National Center for Complementary and Integrative Health, National Institutes of Health. Diabetes and Dietary Supplements. Accessed December 18 2015 at:

4. Ngo MQ, et al. Oral aloe vera for treatment of diabetes mellitus and dyslipidemia. Am J Health Syst Pharm. 2010;67(21):1804-1811.

5. Agency for Healthcare Research and Quality. Effects of omega-3 fatty acids on lipids, glycemic control in type II diabetes and the metabolic syndrome and on inflammatory bowel disease, rheumatoid arthritis, renal disease, systemic lupus erythematosus, and osteoporosis. Accessed December 18 2015 at:

6. Kanaya AM, et al. Restorative yoga and metabolic risk factors: the Practicing Restorative Yoga vs. Stretching for the Metabolic Syndrome (PRYSMS) randomized trial. J Diabetes Complications. 2014;28(3):406–412.

7. Siu PM, et al. Effects of 1-year yoga on cardiovascular risk factors in middle-aged and older adults with metabolic syndrome: a randomized trial. Diabetol Metab Syndr. 2015 Apr 30;7:40.

8. Hayashi T, et al. Laughter up-regulates the genes related to NK cell activity in diabetes. Biomed Res. 2007 Dec;28(6):281-285.

9. Hayashi T, Murakami K. The effects of laughter on post-prandial glucose levels and gene expression in type 2 diabetic patients. Life Sci. 2009 Jul 31;85(5-6):185-187.