Type 2 diabetes doesn’t just affect blood sugar and insulin secretion—it also can lead to a host of other problems including kidney damage, blood vessel thickening, nerve damage and pain. Find out more below about common alternative and complementary methods, vitamins, minerals, herbs and foods used to treat type 2 diabetes and other conditions associated with it.
Two small controlled human trials have found that aloe, either alone or in combination with the oral hypoglycemic drug, glibenclamide, effectively lowers blood sugar in people with type 2 diabetes.
Alpha Lipoic Acid
Alpha lipoic acid is a powerful natural antioxidant. Preliminary and double blind trials have found that supplementing 600 to 1,200 mg of lipoic acid per day improves insulin sensitivity and the symptoms of diabetic neuropathy. In a preliminary study, supplementing with 600 mg of alpha lipoic acid per day for 18 months slowed the progression of kidney damage in patients with type 2 diabetes.
In a small pilot study, 3 grams of American ginseng was found to lower the rise in blood sugar following the consumption of a drink high in glucose by people with type 2 diabetes.
Because oxidation damage is believed to play a role in the development of diabetic retinopathy, antioxidant nutrients might be protective. One doctor has administered a daily regimen of 500 mcg selenium, 800 IU vitamin E, 10,000 IU vitamin A, and 1,000 mg vitamin C for several years to 20 people with diabetic retinopathy. During that time, 19 of the 20 people showed either improvement or no progression of their retinopathy. People who wish to supplement with more than 250 mcg of selenium per day should consult a healthcare practitioner.
More from Preventions: 8 Foods With Antioxidant Power
A double-blind trial found that 200 mg of Asian ginseng per day improved blood sugar levels in people with type 2 diabetes.
Preliminary studies on holy basil and hairy basil have shown that the leaf and seed may help people with type 2 diabetes control their blood sugar levels. While the action-mechanism of the leaf is not understood, the seed may work by providing dietary fiber, which helps prevent rapid blood sugar elevations after meals.
Anthocyanosides, the flavonoid complex in bilberries, are potent antioxidants. They support normal formation of connective tissue and strengthen capillaries in the body. Anthocyanosides may also improve capillary and venous blood flow. Bilberry may also prevent blood vessel thickening due to type 2 diabetes.
Biotin is a B vitamin needed to process glucose. When people with type 2 diabetes were given 9 mg of biotin per day for two months, their fasting glucose levels dropped dramatically. Biotin may also reduce pain from diabetic nerve damage. Some doctors try 9 to 16 mg of biotin per day for a few weeks to see if blood sugar levels will fall.
At least three different groups of constituents in bitter melon have been reported to have blood-sugar lowering actions of potential benefit in type 2 diabetes. These include a mixture of steroidal saponins known as charantin, insulin-like peptides, and alkaloids. It is still unclear which of these is most effective, or if all three work together. Some clinical trials have confirmed the benefit of bitter melon for people with diabetes.
Cayenne contains a resinous and pungent substance known as capsaicin. Numerous double-blind trials have proven topically applied capsaicin creams are helpful for a range of conditions, including nerve pain in diabetes (diabetic neuropathy).
Chromium has been shown to improve glucose levels and related variables in people with glucose intolerance and gestational, steroid-induced and type 2 diabetes. Improved glucose tolerance with lower or similar levels of insulin has been reported in more than ten trials of chromium supplementation in people with varying degrees of glucose intolerance. Chromium supplements improve glucose tolerance in people with type 2 diabetes, apparently by increasing sensitivity to insulin. Chromium improves the processing of glucose in people with prediabetic glucose intolerance and in women with diabetes associated with pregnancy. Chromium even helps healthy people, although one such report found chromium useful only when accompanied by 100 mg of niacin per day. Chromium may also lower levels of total cholesterol, LDL cholesterol, and triglycerides (risk factors in heart disease).
Test tube studies show that cinnamon can augment the action of insulin. However, use of cinnamon to improve the action of insulin in people with type 2 diabetes has yet to be proven in clinical trials.
Coenzyme Q10 (CoQ10) is needed for normal blood sugar metabolism. Animals with diabetes have been reported to be CoQ10 deficient. People with type 2 diabetes have been found to have significantly lower blood levels of CoQ10 compared with healthy people. In one trial, blood sugar levels fell substantially in 31% of people with diabetes after they supplemented with 120 mg per day of CoQ7, a substance similar to CoQ10. The importance of CoQ10 supplementation for people with diabetes remains an unresolved issue, though some doctors recommend approximately 50 mg per day as a way to protect against possible effects associated with diabetes-induced depletion. (Read more about CoQ10 with the Best Supplements For Women.)
Lagerstroemia speciosa, commonly known as crepe myrtle, grows in various tropical countries and Australia. In folk medicine it has been used to treat diabetes. In a preliminary study of people with type 2 diabetes, supplementing with an extract from the leaves of Lagerstroemia speciosa for two weeks resulted in a fall in blood-glucose levels averaging 20 to 30%. The amount used was 32 or 48 mg of a product standardized to contain 1% corosolic acid (a putative active ingredient). The larger amount was somewhat more effect than the smaller amount. Although these results are promising, additional studies are needed to demonstrate the long-term safety and efficacy of this herbal preparation.
Evening Primrose Oil
Supplementing with 4 grams of evening primrose oil per day for six months has been found in double-blind research to improve nerve function and to relieve pain symptoms of diabetic neuropathy.
One human study found that fenugreek can help lower cholesterol and blood sugar levels in people with moderate atherosclerosis and type 2 diabetes. Preliminary and double-blind trials have found that fenugreek helps improve blood sugar control in patients with type 1 and type 2 diabetes.
Glucose tolerance improves in healthy people taking omega-3 fatty acid supplements, and some studies have found that fish oil supplementation also improves glucose tolerance, high triglycerides, and cholesterol levels in people with type 2 diabetes. And in one trial, people with diabetic neuropathy and diabetic nephropathy experienced significant improvement when given 600 mg three times per day of purified eicosapentaenoic acid (EPA)—one of the two major omega-3 fatty acids found in fish oil supplements—for 48 weeks. However, other studies have found that type 2 diabetes worsens with fish oil supplementation. Until this issue is resolved, people with diabetes should feel free to eat fish, but they should consult a doctor before taking fish oil supplements.
In a preliminary trial, supplementation with fructo-oligosaccharides (FOS) (8 grams per day for two weeks) significantly lowered fasting blood-sugar levels and serum total-cholesterol levels in people with type 2 diabetes. However, in another trial, supplementing with FOS (15 grams per day) for 20 days had no effect on blood-glucose or lipid levels in people with type 2 diabetes. In addition, some double-blind trials showed that supplementing with FOS or galacto-oligosaccharides (GOS) for eight weeks had no effect on blood-sugar levels, insulin secretion, or blood lipids in healthy people. Because of these conflicting results, more research is needed to determine the effect of FOS on diabetes and lipid levels.
Ginkgo biloba extract may prove useful for prevention and treatment of early-stage diabetic neuropathy, though research is at best very preliminary in this area.
Glucomannan is a water-soluble dietary fiber derived from konjac root (Amorphophallus konjac) that delays stomach emptying, leading to a more gradual absorption of dietary sugar. This effect can reduce the elevation of blood sugar levels that is typical after a meal. After-meal blood sugar levels are lower in people with diabetes given glucomannan in their food, and overall diabetic control is improved with glucomannan-enriched diets, according to preliminary and controlled clinical trials. One preliminary report suggested that glucomannan may also be helpful in pregnancy-related diabetes. For controlling blood sugar, 500 to 700 mg of glucomannan per 100 calories in the diet has been used successfully in controlled research.
The hypoglycemic (blood sugar-lowering) action of gymnema leaves was first documented in the late 1920s. This action is attributed to members of a family of substances called gymnemic acids. Gymnema leaves raise insulin levels, according to research in healthy volunteers. Based on animal studies, this may be due to regeneration of the cells in the pancreas that secrete insulin, or by increasing the flow of insulin from these cells. Other animal research shows that gymnema can also reduce glucose absorption from the intestine, improve uptake of glucose into cells, and prevent adrenal hormones from stimulating the liver to produce glucose, thereby reducing blood sugar levels.
Hibiscus is a traditional remedy in India for diabetes; this treatment is supported by preliminary studies from that country and by animal studies. Hibiscus is usually taken as tea, such as 1 to 2 teaspoons (3 to 6 grams) of dried flower infused in to 1 cup (250 ml) three times per day.
Inositol is needed for normal nerve function. Diabetic neuropathy has been reported in some, but not all, trials to improve with inositol supplementation (500 mg taken twice per day).
L-carnitine is an amino acid needed to properly utilize fat for energy. When people with diabetes were given DL-carnitine (0.5 mg per 2.2 pounds of body weight), high blood levels of fats—both cholesterol and triglycerides—dropped 25 to 39% in just ten days in one trial.
People with type 2 diabetes tend to have low magnesium levels. Double-blind research indicates that supplementing with magnesium overcomes this problem. Magnesium supplementation has improved insulin production in elderly people with type 2 diabetes. However, one double-blind trial found no effect from 500 mg magnesium per day in people with type 2 diabetes, although twice that amount led to some improvement. Elders without diabetes can also produce more insulin as a result of magnesium supplements, according to some, but not all, trials. However, in people with type 2 diabetes who nonetheless require insulin, Dutch researchers have reported no improvement in blood sugar levels from magnesium supplementation. The American Diabetes Association acknowledges strong associations between magnesium deficiency and insulin resistance but has not said magnesium deficiency is a risk factor. Many doctors, however, recommend that people with diabetes and normal kidney function supplement with 200 to 600 mg of magnesium per day. (Learn more about magnesium.)
Based on the results of a short-term clinical trial that found that medium-chain triglycerides (MCT) lower blood glucose levels, a group of researchers investigated the use of MCT to treat people with type 2 diabetes. Supplementation with MCT for an average of 17.5% of their total calorie intake for 30 days failed to improve most measures of diabetic control.
Test tube and animal studies suggest that mistletoe extracts can stimulate insulin secretion from pancreas cells and may improve blood sugar levels in people with type 2 diabetes. Given both mistletoe’s tradition around the world for helping people with diabetes and these promising preclinical results, human clinical trials are needed to establish mistletoe’s potential for this condition.
Multiple Vitamin-Mineral Supplements
In a double-blind study, supplementation of middle-aged and elderly diabetics with a multiple vitamin and mineral preparation for one year reduced the risk of infection by more than 80%, compared with a placebo.
Olive leaf extracts have been employed experimentally to lower elevated blood-sugar levels in animals with diabetes. These results have not been reproduced in human clinical trials and as such, no clear conclusions can be made from this animal study in the treatment of diabetes.
Two sets of compounds make up the majority of onion’s known active constituents—sulfur compounds, such as allyl propyl disulphide (APDS), and flavonoids, such as quercetin. APDS has been shown to block the breakdown of insulin by the liver and possibly to stimulate insulin production by the pancreas, thus increasing the amount of insulin and reducing sugar levels in the blood. Several uncontrolled human studies and at least one double-blind clinical trial have shown that large amounts of onion can lower blood sugar levels in people with type 2 diabetes. Onion does not reduce blood sugar levels in healthy nondiabetic people.
Psyllium supplementation has improved blood sugar levels in some people with diabetes. The soluble fiber component of psyllium is believed to account for this effect.
Doctors have suggested that quercetin might help people with diabetes because of its ability to reduce levels of sorbitol—a sugar that accumulates in nerve cells, kidney cells, and cells within the eyes of people with type 2 diabetes—and has been linked to damage to those organs. Clinical trials have yet to explore whether quercetin actually protects people with diabetes from neuropathy, nephropathy, or retinopathy. (Learn more about quercetin here.)
Animal studies and some very preliminary trials in humans suggest reishi may have some beneficial action in people with type 2 diabetes and cancer.
Starch blockers are substances that inhibit amylase, the digestive enzyme required to break down dietary starches for normal absorption. Controlled research has demonstrated that concentrated starch blocker extracts, when given with a starchy meal, can reduce the usual rise in blood sugar levels of both healthy people and diabetics. While this effect could be helpful in controlling type 2 diabetes, no research has investigated the long-term effects of taking starch blockers for this condition.
A controlled trial in Africa found that supplementing with both vitamin B1 (25 mg per day) and vitamin B6 (50 mg per day) led to significant improvement of symptoms of diabetic neuropathy after four weeks. However, since this was a trial conducted among people in a vitamin B1–deficient developing country, these improvements might not occur in other people with diabetes. Another trial found that combining vitamin B1 (in a special fat-soluble form) and vitamin B6 plus vitamin B12 in high but variable amounts led to improvement in some aspects of diabetic neuropathy in 12 weeks. As a result, some doctors recommend that people with diabetic neuropathy supplement with vitamin B1, though the optimal level of intake remains unknown.
The intake of large amounts of niacin (a form of vitamin B3), such as 2 to 3 grams per day, may impair glucose tolerance and should be used by people with type 2 diabetes only with medical supervision. Smaller amounts (500 to 750 mg per day for one month followed by 250 mg per day) may help some people with type 2 diabetes, though this research remains preliminary.
Many people with type 2 diabetes have low blood levels of vitamin B6. Levels are even lower in people with diabetes who also have nerve damage (neuropathy). Vitamin B6 supplementation has improved glucose tolerance in women with diabetes caused by pregnancy. Vitamin B6 supplementation is also effective for glucose intolerance induced by birth control pills. In a trial that included people with type 2 diabetes, 1,800 mg per day of a special form of vitamin B6—pyridoxine alpha-ketoglutarate—improved glucose tolerance dramatically. Standard vitamin B6 has helped in some, but not all, trials.
Vitamin B12 is needed for normal functioning of nerve cells. Vitamin B12 taken orally has reduced symptoms of nerve damage caused by diabetes in 39% of people studied; when given both intravenously and orally, two-thirds of people improved. In a preliminary trial, people with nerve damage due to kidney disease or to diabetes plus kidney disease received intravenous injections of 500 mcg of methylcobalamin (the main form of vitamin B12 found in the blood) three times a day for six months in addition to kidney dialysis. Nerve pain was significantly reduced and nerve function significantly improved in those who received the injections. Oral vitamin B12 up to 500 mcg three times per day is recommended by some practitioners. (Read more about Vitamin B12.)
Vitamin C may reduce glycosylation. Vitamin C also lowers sorbitol levels in people with type 2 diabetes. Sorbitol is a sugar that can accumulate inside the cells and damage the eyes, nerves, and kidneys of people with diabetes. Vitamin C may improve glucose tolerance in type 2 diabetes, although not every study confirms this benefit. Vitamin C supplementation (500 mg twice a day for one year) has significantly reduced urinary protein loss in people with diabetes. Urinary protein loss (also called proteinuria) is associated with poor prognosis in diabetes. Many doctors suggest that people with diabetes supplement with 1 to 3 grams per day of vitamin C. Higher amounts could be problematic, however. In one person, 4.5 grams per day was reported to increase blood sugar levels. (Learn more about vitamin C.)
Vitamin D is needed to maintain adequate blood levels of insulin. Vitamin D receptors have been found in the pancreas where insulin is made, and preliminary evidence suggests that supplementation can improve some measures of blood sugar control in people with type 2 diabetes. Not enough is known about optimal amounts of vitamin D for people with diabetes, and high amounts of vitamin D can be toxic; therefore, people with diabetes considering vitamin D supplementation should talk with a doctor and have their vitamin D status assessed.
People with low blood levels of vitamin E are more likely to develop type 1 and type 2 diabetes. Vitamin E supplementation has improved glucose tolerance in people with type 2 diabetes in most, but not all, double-blind trials. Vitamin E has also improved glucose tolerance in elderly people without diabetes. Three months or more of at least 900 IU of vitamin E per day may be required for benefits to become apparent.
People with type 2 diabetes tend to be zinc deficient, but some evidence indicates that zinc supplementation does not improve their ability to process sugar. Nonetheless, many doctors recommend that people with type 2 diabetes supplement with moderate amounts of zinc (15 to 25 mg per day) as a way to correct the deficit.
More from Prevention: The 100 Best Supplements For Women