Diabetes and Natural Health Products: Used Often, Understood Better Now

Natural health products are extremely popular in North America. Researchers from the Edmonton Clinic Health Academy at the University of Alberta in Edmonton, Alberta, Canada have assembled a review article that discusses the 10 most common natural health products used by patients with diabetes for diabetic indications. Pharmacists need to understand natural health products so that they can counsel patients, answer questions, and advise patients about potential drug interactions.

The researchers identified the most commonly used natural health products as alpha-lipoic acid (ALA), chromium, magnesium, bitter melon (Momordica charantia), cinnamon, fenugreek, gymnema, milk thistle, white mulberry, and reishi mushroom.

For each natural health product, the authors discuss its origins, its mechanism of action, and safety data with specific attention to its use in people who have diabetes.

Alpha-Lipoic Acid

ALA can increase pancreatic insulin secretion. Patients most likely to use this supplement have peripheral neuropathy, and one control study supports its use in this indication. ALA has no major drug interactions, according to the review.

Chromium

Individuals who have diabetes may use chromium if they have a documented deficiency or have poorly controlled disease. Some evidence indicates that chromium may decrease HbA1_c by 0.6%. Patients who have renal disease should exercise caution when taking chromium. Chromium interacts with levothyroxine.

Magnesium

The review notes that magnesium is generally used to correct documented deficiency, a problem in many patients who have long-standing or uncontrolled diabetes. Magnesium has a number of interactions, and pharmacists should monitor patients to ensure that they are not at risk for interaction.

Bitter Melon

Bitter melon, which may lower glucose levels in patients who have type 1 diabetes, has no identified drug interactions.

Cinnamon

Cinnamon — the herbal version (cassia) as opposed to the grocery store version (verum) – has also been reported to reduce blood glucose levels. Pharmacists should note that cassia cinnamon contains coumarin, and at high doses may cause or contribute to hepatotoxicity.

Fenugreek

Fenugreek is used often for diabetes due to its propensity to reduce fasting blood sugars and other parameters of diabetes. Patients who have peanut allergy should avoid this drug as there is a possibility of cross-sensitivity. It may also cause some bleeding or bruising.

Gymnema

Gymnema is hypoglycemic and lipid-lowering with patients benefiting most if they take it for 3 months or more. It has no major adverse effects.

Milk Thistle (silymarin)

Milk Thistle (silymarin), a member of the astor family, seems to have some effect in hyperglycemia and hyperlipidemia. Recent study indicates that 600 mg daily of silymarin can reduce fasting blood sugar and decrease the need for insulin by about 20%. This herb has some potential drug interactions via the CYP 450 system, and may interact with tamoxifen, raloxifene, and sirolimus.

Reishi mushrooms

Reishi mushrooms have also been shown to decrease HbA1_c, but should be used with caution in patients have low platelet counts. High doses reduce platelet aggregation. This natural product tends to have more adverse effects than others including dry mouth, pruritus, and gastrointestinal upset.

White Mulberry

Finally, according to the review, white mulberry contains iminosugars that can prevent intestinal digestion and absorption of simple carbohydrates. Studies are conflicting at this time about its appropriate use.

If this information piques interest, pharmacists are well advised to read this entire article. It's well-written, concise, and contains a wealth of information. The authors remind readers that these are not the only natural health products employed by people with diabetes, but they are the most common.

Reference

Necyk C, Zubach-Cassano L. Natural Health Products and Diabetes: A Practical Review. Can J Diabetes. 2017 Aug 18. pii: S1499-2671(17)30327-1. doi:10.1016/j.jcjd.2017.06.014. [Epub ahead of print]