1. Overview & Definitions
Usage of Complementary and Alternative Medicine (CAM) is high among people with diabetes (estimates range from 25% to 57%).
Complementary: Used together with conventional medicine.
Alternative: Used in place of conventional medicine.
Natural Health Products (NHP): Include vitamins, minerals, herbal remedies, and traditional medicines. In Canada, these are regulated and have a Natural Product Number (NPN), but evidence quality is generally lower than for pharmaceuticals.
2. Efficacy of Natural Health Products (NHPs)
The guidelines categorize NHPs based on their ability to lower A1C in randomized controlled trials (RCTs).
A. Products showing potential A1C reduction ( 0.5%) These have shown promise in small trials, but evidence is insufficient to recommend them for widespread use.
- Glycemic Control: Aloe vera (oral), Berberine, Fenugreek (Trigonella foenum-graecum), Ginger, Magnesium, Silymarin (Milk Thistle), Flaxseed oil (high dose).
- Note on Berberine: Meta-analysis shows it may reduce triglycerides and increase HDL more than traditional drugs, and lower BP when used as an adjunct.
B. Products with No Benefit or Conflicting Evidence Despite popular belief, these have generally failed to consistently show benefit for glycemic control in robust studies.
- Cinnamon: Conflicting results; some studies show benefit, others do not.
- Chromium: Meta-analyses show no benefit on A1C, lipids, or weight, despite early theories about deficiency causing insulin resistance.
- Vitamin D: While important for bone health, supplementation does not improve glycemic control (A1C) in people with diabetes.
- Others with lack of benefit: Vitamin C, Vitamin E, Ginseng (variable/heterogeneous), Green Tea (Camellia sinensis).
3. Safety Concerns & Interactions (High Yield for CDE Exam)
CDEs must be vigilant about “natural” products having pharmacological effects or contaminants.
- Xiaoke Pills: A Traditional Chinese Medicine (TCM) that often contains glibenclamide (glyburide). Patients taking this may be at risk of severe hypoglycemia, especially if taking other sulfonylureas.
- St. John’s Wort (Hypericum perforatum): Induces Cytochrome P450 3A4 (CYP3A4). It can reduce the effectiveness of many drugs, including statins and some antihypertensives.
- Bitter Melon (Momordica charantia): Used for glucose lowering, but is an abortifacient and should be avoided in pregnancy.
- Nettle: Has insulin secretagogue activity; potential additive hypoglycemia risk.
4. Other CAM Modalities
A. Mind-Body Practices
- Xiaoke Pills: A Traditional Chinese Medicine (TCM) that often contains glibenclamide (glyburide). Patients taking this may be at risk of severe hypoglycemia, especially if taking other sulfonylureas.
- St. John’s Wort (Hypericum perforatum): Induces Cytochrome P450 3A4 (CYP3A4). It can reduce the effectiveness of many drugs, including statins and some antihypertensives.
- Bitter Melon (Momordica charantia): Used for glucose lowering, but is an abortifacient and should be avoided in pregnancy.
- Nettle: Has insulin secretagogue activity; potential additive hypoglycemia risk.
4. Other CAM Modalities
A. Mind-Body Practices
- Yoga: Regular practice (e.g., 3 times/week) may improve A1C, lipids, and blood pressure. Some data suggests it is more effective than walking or Tai Chi for lowering A1C.
- Tai Chi: Little evidence for glycemic benefit, though may improve quality of life.
B. Physical Treatments
- Acupuncture: No evidence for improving A1C. Some low-quality evidence suggests benefit for diabetic neuropathy symptoms or gastroparesis symptoms .
- Chelation Therapy (EDTA): The TACT trial showed a reduction in cardiovascular events in patients with prior MI and diabetes.
- Reflexology: Small studies suggest potential benefit for neuropathy pain and glycemic control.
5. Diabetes Canada Clinical Practice Guidelines Recommendations
Key takeaways from the “Recommendations” section (Page S157).
- Ask the Question: Health-care providers should ask about the use of complementary and alternative medicine in people with diabetes [Grade D, Consensus].
- Insufficient Evidence: There is insufficient evidence to make a recommendation regarding the efficacy and safety of CAM for individuals with diabetes [Grade D, Consensus].
- Interpretation: Do not actively recommend these products for diabetes management, but be prepared to discuss safety/interactions if patients use them.