Insulin resistance causes high blood sugar levels for people with prediabetes and type 2 diabetes, according to the Centers for Disease Control and Prevention. Various nutritional supplements are being studied to see if they improve the body's ability to use insulin, which can help keep blood sugars in a healthy range.
The National Center for Complementary and Integrative Health lists the possible benefits of several nutritional supplements (including cinnamon and berberine) for diabetes management, but acknowledges that more research is needed. In the meantime, here are the supplements that have shown the most promise in reducing insulin resistance; you may wish to try them to see if you experience positive results, but remember that it's always best to consult your doctor before making any dietary changes.
Read more: The 10 Best Supplements
Chromium and Blood Sugar
Chromium is an essential trace mineral that the body uses to metabolize fats and carbohydrates. It works through a complex mechanism to boost the effectiveness of insulin.
A meta-analysis published in March 2014 in the Journal of Pharmacy and Therapeutics found that chromium supplements improved patients' average blood sugar levels over a three-month period. The researchers suggested that more than 200 micrograms of chromium were needed to see a benefit. But they also noted that the long-term benefit and safety of chromium supplementation needs further investigation. Indeed, according to the National Institutes of Health (NIH), there is no recommended dietary allowance (RDA) for chromium, although an adequate daily intake for adults is between 20 and 35 micrograms.
Read more: What Is the Best Source of Chromium in Food?
Alpha-Lipoic Acid (ALA) and Oxidative Stress
ALA is an antioxidant naturally produced by the body. Like other antioxidants, it reduces the harmful effects of oxidative stress, a complex molecular imbalance common in people with chronic illnesses, including diabetes. Oxidative stress is thought to be a factor in the development and progression of diabetes and its associated complications, such as neuropathy (nerve damage), per a review published in the September 2016 Saudi Pharmaceutical Journal.
Some research suggests that oxidative stress may also contribute to insulin resistance. This has led to interest in using supplemental ALA as a possible way to counteract insulin resistance, according to the Cleveland Clinic.
Though early studies on ALA and insulin sensitivity show promising results, the studies to date have been small. Additional research is needed to confirm whether or not oral ALA truly is beneficial for people with diabetes, especially since taking ALA in high doses may cause nausea or stomach upset.
Omega-3 Fatty Acids and Heart Health
Omega-3 fatty acids — abundant in fish oil, certain vegetable oils and some nuts — are best known for their role in heart disease prevention, according to the Mayo Clinic. This is important to insulin resistance because having diabetes also increases the risk of heart disease.
A study published in the Journal of Physiology and Biochemistry in September 2013 examined whether fish oils could improve insulin sensitivity, but the results were inconclusive. Though the American Diabetes Association recommends consuming omega-3s to reduce your risk of heart disease (by eating fatty fish like salmon twice per week), it does not specifically recommend these supplements for insulin-resistance treatment.
Magnesium and Diabetes Risk
Magnesium is an essential mineral that plays a crucial role in the body's ability to produce and use insulin. Low magnesium levels are common in people with type 2 diabetes, and magnesium deficiency can lead to increased insulin resistance, according to a study published August 2015 in World Journal of Diabetes. Other studies have also found that having low magnesium levels may increase your risk of developing type 2 diabetes.
But according to Heidi Karner, RDN, a nutritionist at Joslin Diabetes Center in Boston, it's better to get your magnesium naturally instead of via supplements. That way, "you're getting all the other positive effects from [the food], such as fiber, vegetables and healthy fats," she says. Good dietary sources of magnesium include dairy, legumes and nuts.
Zinc's Link to Insulin
Zinc is another mineral that's essential to the body's ability to release, process and store insulin, according to a study published March 2017 in Preventive Nutrition and Food Science. People with type 2 diabetes have lower-than-normal levels of zinc in their bloodstream, and higher levels in their urine. This is because they urinate more frequently than people who don't have diabetes, which causes them to lose important nutrients, according to a study published September 2018 by iMedPub Journals.
Additionally, a study published May 2018 in the Journal of Diabetes found that zinc supplements both reduced blood sugar levels and improved insulin sensitivity. And according to a study published in Antioxidants in March 2017, there is also evidence that zinc helps protect cells from damage caused by oxidative stress, which is a factor in diabetes progression.
According to the NIH, the recommended dietary allowance for zinc is 8 micrograms per day for women and 11 micrograms per day for men.
What's the Verdict?
The potential role of nutritional supplements in insulin-resistance treatment is still being investigated. According to Osama Hamdy, MD, director of the inpatient diabetes program at the Joslin Diabetes Center, there is currently no clinical evidence to prove that dietary supplements benefit diabetes management.
If you do decide to try them, supplements should never be your only means of blood sugar control. And keep in mind that they can interact with diabetes medications and other drugs, causing potentially dangerous side effects. That's why, if you're interested in adding supplements to your regimen, it's important that you talk with your healthcare provider first. Adjustments to your medication dosages might be necessary, but you should never change your dosage or stop taking your diabetes medications unless your doctor has instructed you to do so.
Is This an Emergency?
- National Center for Complementary and Integrative Health: "Diabetes and Dietary Supplements"
- Antioxidants: "Zinc and Oxidative Stress: Current Mechanisms"
- iMedPub Journals: "Role of Zinc Supplementation on Diabetes"
- Preventive Nutrition and Food Science: "Zinc in Pancreatic Islet Biology, Insulin Sensitivity, and Diabetes"
- World Journal of Diabetes: "Magnesium and Type 2 Diabetes"
- American Diabetes Association: "Diabetes Superfoods"
- Journal of Physiology and Biochemistry: "Role of Omega-3 Fatty Acids in Obesity, Metabolic Syndrome, and Cardiovascular Diseases"
- Indian Journal of Endocrinology and Metabolism: "A Review of the Effect of Omega-3 Fatty Acids in the Cardiovascular System"
- Cleveland Clinic: "Alpha-Lipoic Acid"
- Saudi Pharmaceutical Journal: "Diabetes Mellitus and Oxidative Stress"
- Journal of Clinical Pharmacy and Therapeutics: "Systematic Review and Meta‐analysis of the Efficacy and Safety of Chromium Supplementation in Diabetes"
- Journal of Diabetes: "Zinc Supplementation in Prediabetes"
- Mayo Clinic: "Omega-3 in fish: How eating fish helps your heart"
- Centers for Disease Control and Prevention: "The Insulin Resistance–Diabetes Connection"
- National Institutes of Health: "Chromium"
- National Institutes of Health: "Zinc"