Natural Treatment for Diabetes
Reviewed by: HU Medical Review Board | Last reviewed: May 2022 | Last updated: May 2022
Many people search for alternative and complementary methods of managing their diabetes through the use of vitamins, herbal medicines, and nutritional supplements. Some of these products have been evaluated for their effects on glycemic control and insulin resistance, and their treatment of diabetes complications.1 However, the FDA does not test the effectiveness of herbals and supplements or fully regulate their claims. Therefore, there is not a lot of scientific evidence on supplements or herbal medicines to help validate their safety or their effectiveness in helping manage diabetes. Consult with your healthcare provider before taking any alternative medicines, as some may have serious drug interactions or adverse side effects.
Alpha-lipoic acid
Alpha-lipoic acid is an antioxidant chemical available as a supplement and contained in certain foods, including yeast, broccoli, spinach, and potatoes. Antioxidants are chemical substances that protect against cell damage. Results from several small studies suggest that alpha-lipoic acid may improve blood glucose in patients with type 2 diabetes.3
Beta-glucan
Beta-glucan is a type of fiber derived from algae, bacteria, fungi, yeast, and plants. It is typically used to lower blood lipids (LDL cholesterol). There is some data from human studies showing that beta-glucan may help control blood glucose in patients with type 2 diabetes. However, further studies are necessary to confirm these findings.3
Berberine
Berberine is an herb with a long history of use in Chinese herbal medicine. It is derived from the roots and stem bark of various plants, including goldenseal. It has antibiotic properties and has been shown in laboratory studies to have glucose- and lipid-lowering properties. A randomized, controlled trial of berberine in 60 subjects with type 2 diabetes found significant decreases in a range of fatty acids in subjects treated with berberine. This finding suggests a potential role for berberine in lower blood lipids and promoting cardiovascular health.1,3 The effect of berberine on glycemic control has not been established in studies.3
Chromium
Chromium is a trace metal available in small quantities in many different foods, including whole grains, mushrooms, brown rice, meat, broccoli, and other fresh vegetables. One good dietary source of chromium is brewer’s yeast. Herbal sources of chromium include wild yam, licorice, red clover, sarsaparilla, and nettle. Chromium has been shown to enhance the effects of insulin. Chromium deficiency has been linked to the signs of diabetes in cases of hospitalized patients, with supplementation correcting diabetes symptoms. These and other findings have led to interest in the potential use of chromium supplementation in diabetes treatment. However, results from research to date have been inconclusive.4
Ginseng
Results from several studies suggest that the plant-derived product American ginseng (Panax quinquefolium) may have blood glucose lowering properties in patients with type 2 diabetes. However, there is currently insufficient data to support the safe use of ginseng as a treatment in diabetes. It is thought that ginseng may increase the effects of oral diabetes medications. Therefore, it should be used with caution in patients who are being treated with these drugs.3
Gurmar
Gurmar (Gymnea sylvestre) is derived from a rainforest plant called gurmar (this literally means “sugar destroyer” in Hindi). This natural product has been used to treat diabetes for centuries in Ayurvedic medicine and has been shown to stimulate secretion of insulin by pancreatic beta cells. A recent pilot study of a treatment containing the active ingredient in gurmar conducted in 11 subjects (10 of whom had type 2 diabetes) reported significant increases in insulin and evidence of significant decreases in blood glucose (both fasting and non-fasting).1 Further studies are needed to confirm these potential benefits and the usefulness of gurmar in diabetes management.3
Magnesium
The mineral magnesium plays a key role in helping the body process glucose. Several studies of dietary magnesium consumption have shown that people who have lower magnesium consumption have an increased risk of developing type 2 diabetes. In one study, people with a magnesium-rich diet had a 15% reduced risk of developing diabetes. Despite these findings about dietary magnesium and diabetes risk, there is currently no evidence that magnesium supplementation provides any benefit in diabetes management. Apart from decreasing diabetes risk, magnesium may provide a small benefit in lowering blood pressure. Magnesium can be taken as a supplement or by eating foods rich in the mineral, including whole grains, nuts and green leafy vegetables. The safety of long-term magnesium supplementation in people with diabetes has not been studied. However, very large doses of magnesium (over 5,000 mg/day) are considered to be dangerous.3
Cinnamon
Cinnamon, another rich source of polyphenols and a commonly used substance in Chinese herbal medicine, has been shown to have effects on both insulin signaling (the signals the body sends to increase insulin secretion) and blood glucose regulation. An analysis of combined results from eight clinical trials of cinnamon (taken as an extract or in whole form) used in subjects with type 2 diabetes found significant reductions in fasting plasma glucose. Another randomized, controlled trial conducted in 58 patients with type 2 diabetes reported significant decreases in hemoglobin A1C, as well as beneficial changes in blood pressure.1 Despite these findings, a 2012 review of existing evidence from 10 randomized, controlled trials concluded that there was insufficient evidence to recommend the use of cinnamon for the treatment of either type 1 or 2 diabetes.2
In addition to conflicting study results, there are safety concerns related to the use of cinnamon as part of treatment for diabetes. One study found that samples of the spice cinnamon in grocery stores contained coumarin, a compound found to interact with blood thinners such as Coumadin(warfarin) and may increase the risk of bleeding for people being treated with it.2
Garlic
The potential role of garlic in diabetes management has been evaluated in a placebo-controlled study conducted in 60 subjects with type 2 diabetes. In this study, garlic tablets were given along with metformin. After 24-weeks of treatment, subjects who received garlic tablets (allium sativum 300 mg, 3 times daily) had significantly greater decreases in fasting plasma glucose levels and significant improvements in blood lipids (total cholesterol, triglycerides) versus controls. These results have not been confirmed in other studies and further research is needed.1
There are also some safety concerns related to the use of garlic. Similar to cinnamon, garlic may also interact with blood thinners, such as warfarin, and increase the risk of bleeding for people taking the medication.10
Flaxseed
Results from a small number of low-quality studies suggest that oral flaxseed has mixed effects on blood glucose. One of these studies reported increased blood glucose in patients treated with omega-3 fatty acids, which are contained in flaxseed oil. Other studies conducted in healthy individuals found that flaxseed oil supplementation resulted in no change in blood glucose. There are too few well-designed studies to recommend the benefits of flaxseed supplementation for glycemic control in people with diabetes.5
Calcium and Vitamin D
An analysis and review of results from several studies evaluating the effects of dietary intake and supplementation with vitamin D combined with calcium on diabetes risk found that the combination decreased risk for developing type 2 diabetes. However, in other studies, including a large, long-term study in post-menopausal women, found that vitamin D supplements were no more effective than placebo in reducing diabetes risk.2,6
Vitamin D is recognized as important in maintaining bone health. It also plays an important role in immune system function. Dietary sources for vitamin D include fish, eggs, fortified milk, and fish oil (cod liver oil). Vitamin D is also produced by the body during exposure to the sunlight. Sun exposure for as little as 10 minutes may be sufficient to prevent deficiencies of vitamin D.2,6
In one placebo-controlled study conducted in patients with pre-diabetes, calcium supplementation (1,500 mg daily for 8 weeks) improved insulin sensitivity. Despite these promising results, further studies are necessary to confirm benefits of calcium alone or in combination with vitamin D in patients at risk for developing type 2 diabetes.7
Dietary sources of calcium include dairy products, leafy vegetables, and eggs.
Green tea and alma
A combination of Epigallocatechin gallate (substance in green tea) and alma (a substance extracted from Indian gooseberry) was evaluated in a small study in subjects with type 2 diabetes and found to result in improvements in plasma glucose levels, lipids (LDL/HDL ratio), and measurements of oxidative stress.1
Glucomannan
Glucomannan is a dietary fiber derived mainly from the root of the elephant yam or konjac plant. It has traditional used in Asia as a food source and topical ointment and more recently has been introduced as a dietary supplement. Glucomannan has been shown to have blood glucose lowering effects that are thought to result form its action in delaying gastric emptying, which slows delivery of dietary glucose to the intestines. In preliminary studies in humans, glucomannan resulted in decreases in non-fasting glucose and depressed appetite in individuals with type 2 diabetes. Other studies have shown glucomannan to be useful in both lowering blood lipids and weight loss. Further research is needed to clarify the potential use including the safety of glucomannan in diabetes management.8
Guar gum
Guar gum is derived from the guar bean (Cyamopsis tetragonoloba), a plant grown throughout parts of India and Pakistan. It is used as a thickening agent and is available in a range of nutritional supplements. Results from several studies show that guar gum may be beneficial in reducing cholesterol and promoting bowel function. There is also evidence that it has a modest effect in improving non-fasting blood glucose levels in both diabetic and non-diabetic individuals. In studies of 48 weeks and 4 weeks, daily guar gum supplements resulted in improved glycemic control and glucose tolerance in patients with type 2 diabetes. However, other studies conducted in diabetic and non-diabetic patients found no evidence of glycemic benefit. Further well-designed studies are needed to clarify potential benefits of guar gum in patients with diabetes.9