Dietary Supplements for Diabetes?

The incidence of diabetes is increasing at an alarming rate worldwide.  Worldwide, approximately 250 million people have diabetes—according to the World Health Organization.  In Canada, the number of patients with diabetes is projected to increase from 1.4 million in 2000 to 2.4 million in 2016 [1].  What’s more, is that the health care cost associated with this increase in Canada will jump from $4.6 billion in 2000 to $8.14 billion in 2016.

Keep in mind that even these projections do not include people who have type 2 diabetes, but haven’t yet been diagnosed.  Overall, approximately 90% of diabetics have type 2 diabetes.

Studies suggest that anywhere from 8 to 49% of patients with diabetes use nutritional supplements.  A recent review article published in the journal, Current Diabetes Reports, provides a review of the effectiveness of various supplements for preventing or treating diabetes [2].

On their list of potentially effective supplements, they include:

• α-lipoic acid
• melatonin
• red mold (red yeast rice)
• Aloe vera
• astragalus
• cassia cinnamon
• vitamins c and e
• rheum officinale

While the standard treatment for type 2 diabetes includes lifestyle modification (diet, exercise) along with pharmaceutical drugs, an increasing number of patients with diabetes are using complementary and alternative therapies.  Of those listed as potentially effective, which ones actually work according to the previously cited review study?

Vitamins, supplements, and herbal remedies for diabetes?

Antioxidants:

While numerous studies show that an increase in oxidative stress resulting from hyperglycemia and hyperlipidemia plays a role in the pathogenesis of type 2 diabetes, results for studies on supplementation with vitamin e, c, and beta carotene have been less than promising.  In human studies, antioxidants have not been effective at preventing diabetes.

1. Alpha-Lipoic acid:

α-Lipoic acid is an antioxidant that is used by your body as a coenzyme.  Oral dosages of 600 mg have been shown to be effective at improving neuropathic symptoms (burning, pain) in patients with type 2 diabetes.  Higher dosages of 1200 and 1800 mg are more likely to produce side effects such as vertigo, nausea, and vomiting.

Alpha-lipoic acid and weight loss?

One recent study published in the September 2011 edition of the journal, American Journal of Medicine (Koh et al, 2011) found that supplementation with alpha-lipoic acid was somewhat effective for helping those with obesity lose weight.

In their 20 week trial, obese subjects taking 1800 mg/d of alpha-lipoic acid lost approximately 2% more bodyweight than those taking placebo.

2. Melatonin:

Melatonin is both a hormone that regulates circadian rhythms as well as an antioxidant.  Studies suggest that patients with diabetes have lower levels of melatonin.   As well, melatonin appears to play a favorable role in the regulation of insulin levels.  Future studies are needed to further determine the role of melatonin supplementation in patients with diabetes.

3. Astragalus:

Astragalus is a herb used in traditional Chinese medicine.  In Chinese medicine, it’s referred to as Huang Qi.  Though studies in humans are scarce, studies in animal models suggest that it helps to lower glucose levels and improve insulin sensitivity.  Dosing for humans is still not well-established.

4. Red Mold (Red Yeast Rice):

Red Yeast Rice has been more extensively studied for its effectiveness in lowering LDL cholesterol levels.  Macrovascular complications such as heart attacks and strokes are the most common cause of mortality in patients with diabetes.  For patients with type 2 diabetes, treatment guidelines typically recommend even tighter control of LDL cholesterol levels than the general population for this reason.

Red Yeast Rice has been less extensively studied for its potential role in treating diabetes itself rather than lowering cholesterol levels.  Again in an animal model, one study found that it reduced the amount of glucose and protein in the urine.  This may indicate that it has a potentially beneficial role in preventing renal complications in patients with diabetes though this has not been confirmed in human trials.

5. Emodin:

Emodin is a compound that is found naturally in the leaves of aloe vera as well as in the roots of the rhubarb plant.  Animal models have suggested that it may play a role in decreasing body weight, insulin resistance, and glucose levels in diabetes.  However, again these results have not been confirmed in human trials.  In fact, there is very little information regarding its safety, effective dosage, or pharmacokinetics in humans.

6. Cinnamon:

The study authors note that there are some mixed results regarding the effectiveness of cinnamon in patients with type 2 diabetes.  However, they cited a recent study by Crawford et al (2009, [3]) which found that supplementation with 1 g daily of cassia cinnamon capsules for 90 days resulted in a .83% reduction in HbA1C compared to .37% reduction from usual care alone.  A more recent study detailed in a previous blog post on my site found similar results on cinnamon’s effectiveness:  (cinnamon and diabetes).

Conclusions:

From this list of supplements, two things are apparent.  Further studies are needed largely in the form of randomized controlled trials to further understand the efficacy of these supplements.  Secondly, the most robust evidence in the form of human study data currently exists for supplementation with cassia cinnamon capsules.  I would certainly consider it if I had type 2 diabetes since the potential reductions in HBA1C is clinically significant.

For those who suffer from diabetic neuropathy, there’s some evidence that α-lipoic acid may help, so you can also talk to your doctor about that.]

Related posts on diabetes?

• Blueberries Improve Insulin Resistance?
• Do Onions Lower Blood Sugar in Diabetics?
• Does Creatine Monohydrate Improve Blood Sugar?

References:

1. Canadian Diabetes Association Report.
2. Lee T, Dugoua JJ. Nutritional supplements and their effect on glucose control. Curr Diab Rep. 2011 Apr;11(2):142-8.
3. Crawford P. Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial. J Am Board Fam Med 2009;22(5):507–12.
4. Koh EH, Lee WJ, Lee SA, Kim EH, Cho EH, Jeong E, Kim DW, Kim MS, Park JY, Park KG, Lee HJ, Lee IK, Lim S, Jang HC, Lee KH, Lee KU.  Effects of alpha-lipoic Acid on body weight in obese subjects. Am J Med. 2011 Jan;124(1):85.e1-8.