If you have diabetes or know someone with diabetes, you are probably waiting for the miracle that will cure the disease. Unfortunately, there is no magic pill or treatment that will radically improve your diabetes.
However, some supplements may have restorative powers that could make a difference in your blood glucose control and/or decrease your risk of complications. There is a small but growing body of evidence about the value of several herbs and dietary supplements in the management of diabetes.
Remember that these substances are pharmacologically active, like drugs, and can interact with other medications. Moreover, when they are effective, they can combine with current treatments and cause blood glucose to drop too low. As always, it is vital that you undertake any supplement regimen or alternative medicine treatments with close supervision of your physician.
Alpha-lipoic acid (ALA) is an antioxidant—a substance that prevents cell damage. High levels of blood glucose are one cause of cell damage as a result of oxidative stress. As an antioxidant, ALA is helpful in healthy nerve function and may improve diabetic neuropathy. It is theorized that ALA may be beneficial to people with Type 1 or 2 diabetes because of its antioxidant activity.
ALA is a chemical that is similar to a vitamin. ALA is found in some foods, such as liver, spinach, broccoli, and potatoes.
ALA has been studied in many randomized controlled trials that were not always looking at its effect on diabetes. There are a few small studies that have shown hints of beneficial effects. In a few of these studies, some possible benefits from ALA were seen in glucose uptake in muscle, sensitivity of the body to insulin, diabetic neuropathy, and/or weight loss.
While ALA appears to be safe for the general adult population, people with diabetes need to know that ALA might lower blood glucose too much, and thus they need to carefully monitor their blood glucose level during initial treatment. ALA may also lower blood levels of minerals, such as iron; interact with some medicines, such as antacids; and decrease the effectiveness of some anti-cancer drugs. Other possible side effects of ALA include headache, skin rash, nausea, and stomach upset.
The currently recommended dose is 50–100mg daily for glucose and insulin metabolism; 100–600mg daily taken in divided doses for diabetic neuropathy.
Bottom Line: Alpha-lipoic acid is generally safe but should be approached with caution due to its ability to lower blood glucose levels. As an antioxidant, it has potential to deter the complications resulting from prolonged hyperglycemia.
Bitter melon (bitter cucumber) is a vegetable related to the melon family and grows in India, Asia, South America, and Africa. It is eaten as a raw or cooked vegetable and is said to resemble gherkins (small cucumber pickles). Both the fruit and seeds are used in food preparation.
Studies on the use of bitter melon have been small and not well controlled. Bitter melon has been occasionally shown to improve diabetes via an increase in glucose uptake by tissues, inhibition of the enzymes involved in glucose production, and enhancement of glucose oxidation.
Serious side effects have been noticed including favism (a form of anemia) and/or miscarriage. Hypoglycemia may occur with the use of insulin and insulin-producing medications. Less serious consequences include upset stomach.
There is no recommended dosage. The bitter melon can be eaten as part of a meal. Various supplemental forms include juice (usual dose: 2–5 fluid ounces), powder (usual dose: 3–15g), and vegetable pulp suspensions (usual dose: 300–500mg in divided doses).
Bottom Line: You can expect very little change in blood glucose levels without the risk of serious side effects. Eating the melon may be enjoyed but supplements should be used with extreme caution.
Chromium is an essential trace mineral that is important in processing carbohydrates and fats, and helping cells respond properly to insulin. Egg yolks, whole-grain products, high-bran breakfast cereals, coffee, tea, nuts, green beans, broccoli, meat, and some brands of wine and beer are excellent sources of chromium. As a supplement, it is marketed as chromium picolinate, which is the most bioavailable form. The action of chromium may be enhanced when combined with biotin.
Chromium has been used in both Type 1 and Type 2 diabetes. It may improve insulin sensitivity and glucose control. It may also reduce the weight gain that is associated with insulin and certain oral medications. In addition, chromium has been found to improve blood cholesterol and triglyceride levels.
At low doses, short-term use of chromium appears to be safe in the general adult population. However, because of chromium’s ability to lower blood glucose, this might cause blood glucose to go too low. Possible side effects at low doses include headache, insomnia, and skin irritation. High doses can cause serious side effects. The foremost concern is the development of kidney problems. Other possible effects include vomiting, diarrhea, bleeding into the gastrointestinal tract, and worsening of any behavioral or psychiatric problems.
The currently recommended dose is 200mcg/day taken early in the day. In 2005, the FDA allowed a “Qualified Health Claim”, which suggests that chromium is a safe treatment that may have positive benefits on blood glucose and lipid levels.
Bottom line: Low levels of chromium are characteristic of diabetes, but there’s no evidence of a cause-and-effect relationship. Use chromium with caution, especially if you are young or pregnant. To test the effect, look for about a 2% drop in blood glucose levels or about a 0.5% drop in hemoglobin A1c.
For most of us, cinnamon is associated with pleasant thoughts of spiced cider or apple pie. Few realize this spice, from a small evergreen tree native to Sri Lanka and Southern India, dates back to biblical times. Fewer still are aware that cinnamon bark has medicinal effects.
Cinnamon has been shown to reduce blood glucose following a meal. Cinnamon is thought to increase insulin sensitivity as well as increase glucose uptake by the cells. It has also been proposed that the antioxidant properties of cinnamon may influence diabetic complications. Several randomized controlled trials have been conducted on cinnamon and its effects on fasting glucose, hemoglobin A1C and lipid profile markers.
Cinnamon has very few ill effects unless taken in extreme doses. However, as with any glucose-lowering treatment, use caution if taking insulin or oral medications. In addition, cinnamon contains a compound that interferes with blood coagulation and may interfere with warfarin treatment.
The suggested dose is 1–6g daily which is equivalent to ½ to 2 teaspoons of powdered cinnamon.
Bottom Line: Cinnamon is one of the few tasty treatments for diabetes. How can that be bad? Although results are sure to vary, you can expect fasting blood glucose levels to lower by about 10% at the most. You might also experience a modest decline in hemoglobin A1c. In addition cinnamon can lower total cholesterol, LDL cholesterol and triglycerides.
Coenzyme Q10, often referred to as CoQ10, is a vitamin-like substance. CoQ10 helps cells make energy and acts as an antioxidant. Meats and seafood contain small amounts of CoQ10.
There have been few studies on CoQ10 and diabetes so far. The evidence is not sufficient to evaluate CoQ10's effectiveness as an alternative therapy in diabetes. CoQ10 has not yet been shown to affect blood glucose control. In theory, it might be protective against heart disease in people with diabetes.
CoQ10 appears to be safe for most of the adult population. However, it may interact with and affect the action of some medicines, including warfarin (a blood thinner) and medicines used for high blood pressure or cancer chemotherapy. Other possible side effects of CoQ10 include nausea, vomiting, diarrhea, loss of appetite, and heartburn.
Usual dose is about 200mg/day.
Bottom Line: Hope for effects on your heart health but not on blood glucose control.
Fenugreek is in the same family as peanuts and chickpeas, and grows in India and the Middle East. The seeds give curry dishes a distinctive taste. Fenugreek seeds have been used for centuries as a digestive aid and to treat constipation but also have been thought to improve Type 1 and 2 diabetes and high blood cholesterol.
By delaying gastric emptying, fenugreek slows carbohydrate absorption. It also is thought to improve insulin secretion as well as sensitivity. It may therefore decrease both fasting and after-meal blood glucose levels.
Side effects are generally minor and include stomach pain or nausea caused by diarrhea and/or gas. More serious potential ill effects are possible uterine contractions and allergic reactions. For these reasons, pregnant women or individuals with known peanut and/or chickpea allergies should not take fenugreek. In addition, high doses of fenugreek may cause hypoglycemia.
Dose is variable but is generally suggested to be 5–15g/day as a single dose or, more preferably, divided and taken with meals.
Bottom Line: If you like to chew on fenugreek seeds before or after a meal, it’s likely to do no harm. Supplemental effects on blood glucose and lipids are likely to be minor.
Garlic is used to flavor food. Garlic flowers, leaves, bark, fruit, seeds, stems, and roots have been employed. Garlic can also be processed and made into dietary supplements. In some cultures, garlic has been used for medicinal purposes for centuries. One of the claims for garlic is that the rates of certain diseases (notably, heart disease, including high blood pressure and high cholesterol) are lower in countries where plenty of garlic is consumed. However, it has not been proven that garlic (and not some other factor such as lifestyle) is the reason.
Few rigorous studies have been conducted on garlic for type 2 diabetes. In the studies that have been done, findings have been mixed. There are some intriguing basic science studies that suggest that garlic has some biological activities that are relevant to the treatment of diabetes.
Garlic as a flavoring agent is safe for most adults. However, when garlic is taken in supplement form or in high doses, it appears to interact with certain drugs. For example, when combined with certain medicines used to treat HIV/AIDS, garlic may decrease their effectiveness. Garlic may also interact with and affect the action of birth control pills, cyclosporine, medications that are broken down by the liver, and blood thinners (including warfarin). Other possible side effects of garlic include an odor on the breath or skin, an allergic reaction, stomach disorders, diarrhea, and skin rash.
Usual recommended dose is 600–1200mg/day in divided doses with enteric coating to prevent breakdown by stomach acids.
Bottom Line: Garlic as a flavoring agent may be used liberally. But if you hope for improvements in blood glucose levels, don’t hold your breath.
Ginseng is a plant found in Asian countries and has been used for centuries to improve blood glucose control, enhance the immune system, and improve physical performance. There are two major forms of ginseng: Asian ginseng and American ginseng.
Studies of ginseng in people with Type 2 diabetes show consistent results but the effects have not been dramatic. Ginseng has not been shown to significantly reduce Hemoglobin A1c levels. However, it can improve blood glucose and insulin regulation.
Ginseng may decrease the rate of carbohydrate absorption from the gut, may increase glucose transport and uptake, and/or may modify insulin secretion.
Ginseng is not without side effects including insomnia, restlessness and nervousness; increase in blood pressure or heart rate; headache; and effect on estrogen levels. In addition, ginseng may decrease the effectiveness of warfarin and/or decrease the effects of diuretics and hypertension medications
Recommended dose is 3g/day for American ginseng and 200mg/day for Asian ginseng.
Bottom line: Try ginseng only if you have Type 2 diabetes and look for minor improvements in fasting and/or after-meal blood glucose levels.
Gymnema is a member of the milkweed family that grows in the tropical forests of central and southern India and in parts of Africa. Ayurvedic practitioners in India have used the leaves of this long, slender plant as a treatment for diabetes for more than 2,000 years.
Gymnema is thought to increase glucose uptake by the cells and insulin release from the pancreas (in both Type 1 and 2 diabetes), while it improves beta cell function and number in patients with Type 2 diabetes.
No serious ill effects have been reported in conjunction with ingesting gymnema but large doses could cause hypoglycemia if taken with insulin or oral medications for diabetes.
Usual dose is about 400mg/day taken in divided doses.
Bottom Line: Gymnema may decrease your hemoglobin A1c modestly and additionally may lower your insulin or oral medication doses.
Magnesium is an essential mineral and has many important functions in the body, including glucose metabolism. Interestingly, people with Type 1 or 2 diabetes often have low magnesium levels. Foods high in magnesium include green leafy vegetables, nuts, seeds, and some whole grains.
There have been relatively few studies on magnesium and diabetes; the results have been mixed. Most studies find that magnesium does not affect blood glucose control. However, some studies have suggested that low magnesium levels may make glucose control worse in diabetes (by interrupting insulin secretion in the pancreas and increasing insulin resistance) and contribute to diabetic complications. Magnesium supplements appear to be safe for most adults at low doses. High doses can be risky and cause such problems as nausea, diarrhea, loss of appetite, muscle weakness, difficulty breathing, extremely low blood pressure, irregular heart rate, and confusion. Magnesium can interact with and affect the action of certain drugs, including some antibiotics, drugs to prevent osteoporosis, certain high blood pressure medicines, muscle relaxants, and diuretics.
There is no recommended dose for supplemental magnesium. For adults, the Daily Reference Intake (DRI) is between 250 and 500mg/day.
Bottom Line: Upsetting the delicate balance of magnesium in the body can lead to problems with many organs including the heart, muscles, and bones. Best to get your daily needs of magnesium met with healthy foods or, if necessary, a well-balanced multi-vitamin/mineral supplement.
Nopal (Prickly Pear)
Nopal is a member of the cactus family. It grows naturally in Mexico and the southwestern part of the United States. Nopal is found in many native recipes; leaves, flowers, stems (pads) or fruit are used.
Although scientific evidence is scant, nopal is thought to slow carbohydrate absorption as well as produce an increase in insulin sensitivity in some individuals.
Side effects are usually minor including diarrhea, nausea, and abdominal fullness. However, nopal can have an additive effect when combined with insulin and sulfonylureas.
Usual dose is 100 to 500mg/day of broiled nopal stems.
Bottom Line: If you like nopal in salads or other Mexican-style dishes, by all means eat generous portions of it. The most you can hope for is a slight decrease in your after-meal blood glucose levels. If you don’t like the taste of nopal, you won’t be missing a miraculous cure for your diabetes.
Omega-3 Fatty Acids
Omega-3 fatty acids (omega-3s, for short) have been the subject of much media attention in recent years. Studies show they may decrease the rate of heart disease, reduce inflammation, and lower LDL-cholesterol and triglyceride levels. Omega-3s have been of interest for diabetes primarily because they may prevent or delay diabetic complications. Omega-3s do not appear to affect blood glucose levels directly.
Dietary sources of omega-3s include fish oils and certain plant or nut oils. Fish oil contains both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), while some nuts (English walnuts) and vegetable oils (flax seed, hemp seed, linseed, olive, canola and soybean) contain alpha-linolenic acid (ALA).
Omega-3s appear to be safe for most adults at low-to-moderate doses. There have been some safety questions raised about fish oil supplements, because certain species of fish can be contaminated with mercury, pesticides, or PCBs. For this reason, women who are pregnant or breastfeeding should not take fish oil supplements. Fish oil in high doses can possibly interact with, and affect the action of, certain medications, including blood-thinning drugs and drugs for high blood pressure. Potential side effects of fish oil include a fishy aftertaste in the mouth, belching, stomach disturbances, and nausea.
Dosing varies but most recommendations point to the equivalent of 1–2g of fish oil or 1–3oz of oily fish daily.
Bottom Line: Even your physician may be recommending omega-3s for your heart health. There are now prescription-strength supplements available. So of all the supplements for diabetes, this one appears to be the most effective for preventing some of the complications of diabetes. Take the supplement with caution or eat more fish.
There is limited scientific evidence on the effectiveness of dietary supplements on diabetes or diabetic complications. The evidence that is available is not sufficiently strong to prove that any of the supplements discussed above have benefits for diabetes. A possible exception may be the use of omega-3 fatty acids. Essential nutrients that the body cannot make on its own but can obtain from foods such as fish and flaxseed or from dietary supplements may lower triglyceride levels.
It is very important not to replace conventional medical therapy for diabetes with unproven therapy. To ensure a safe and coordinated course of care, people should inform their health care providers about any supplemental therapy that they are currently using or considering.
The dietary supplements reviewed here appear to be generally safe at low-to-moderate doses. However, each can interact with various prescription medications, affecting the action of the medications. Prescribed medicines may need to be adjusted.
Good news for people with diabetes could be just around the bend, thanks to all the research currently underway. For now, though, talk to your doctor before popping any pills—even if they’re sold right next to the broccoli!
For more information
NIH Office of Dietary Supplements
National Center for Complementary and Alternative Medicine (NCCAM)
©Gary Scheiner MS, CDCES – Integrated Diabetes Services. May be reproduced and used for patient education, but not sold.