American Diabetes Association Guide to Herbs and Nutritional Supplements. Laura Shane-McWhorter

movement. Oxidative stress is thought to play a role in the progression of diabetic nerve damage. As an anti-oxidant, alpha-lipoic acid may decrease oxidative stress and improve symptoms such as pain. However, there is no evidence that alpha-lipoic acid prevents diabetic nerve damage. In addition, studies have not shown that alpha-lipoic acid significantly decreases blood glucose levels.

      Although alpha-lipoic acid has been used for several years in Germany, long-term trials in the United States are needed determine whether alpha-lipoic acid slows progression or only improves symptoms of nerve damage. Much is still unknown about its use.

      Alpha-lipoic acid is also used to treat many other conditions such as Parkinson’s, Alzheimer’s, cataracts, and glaucoma.

      DOSE

      Typical doses Typical doses of alpha-lipoic acid are 600 to 1,200 milligrams (mg) daily.

      STUDIES

      Alpha-lipoic acid has been studied in a number of randomized, double-blind, placebo-controlled studies (the gold standard design of scientific studies). Overall, these studies have shown that alpha-lipoic acid decreases symptoms of painful diabetic nerve damage when compared to a placebo (dummy pill).

      One series of studies is called the ALADIN (Alpha-Lipoic Acid in Diabetic Neuropathy) trials.

      • In the first ALADIN study, 260 patients with type 2 diabetes and diabetic nerve damage were given an injection of alpha-lipoic acid in various doses (100, 600, or 1,200 mg) or a placebo once a day. The total symptoms of nerve damage decreased in those who were taking any dose of alpha- lipoic acid versus those who were taking a placebo. Burning, tingling, loss of sensation, and numbness decreased significantly in those patients on 600-or 1,200-mg versus a placebo. Pain scores decreased significantly only in the 600- mg group versus the placebo group. The neurodisability score, which measures vibration, pinprick, ankle reflexes, and temperature sensation in the big toe, decreased, but the decrease was significant only for the group taking 1,200-mg versus the placebo group. A1C, a measure of average blood glucose over 3 months, declined in all groups, but not significantly.

      • In the second ALADIN study, 65 patients with type 1 or type 2 diabetes and nerve damage received an injection of alpha-lipoic acid or a placebo for 5 days. Then patients received a 600-or 1,200-mg tablet of alpha-lipoic acid or a placebo daily for 2 years. Researchers measured improvements in nerve damage in the patients. Patients taking either dose of alpha-lipoic acid had significant improvements versus the placebo group, although not for all types of nerve damage. The patients’ neurodisability scores did not decrease, but the sample of patients may have been too small to detect changes. A1C did not decrease significantly, although A1C decreased from 9 percent to 8 percent after years in the 1,200-mg group.

      • The third ALADIN study examined 503 patients with type 2 diabetes. One group of patients received a 600-mg injection of alpha-lipoic acid for 3 weeks and then received either a 600-mg tablet of alpha-lipoic acid three times daily or a placebo for 6 months. The other group received a placebo “injection” for 3 weeks, followed by a placebo tablet for 6 months. Nerve damage impairment decreased after 19 days in both groups of patients who took alpha-lipoic acid versus the placebo. However, after 7 months, there was no significant difference in nerve damage scores between the groups.

      • A separate study evaluated 120 patients who took alpha- lipoic acid 5 days a week for a total of 14 treatments. Symptoms declined significantly.

      • A follow-up to this study evaluated three different doses of alpha-lipoic acid (600, 1,200, or 1,800 mg) versus a placebo for 5 weeks in 181 patients with diabetes. Total symptom scores declined significantly by 51 percent, 48 percent, and 52 percent, respectively, in the alpha-lipoic acid treatment groups versus 32 percent in the placebo group.

      • Yet another study examined the results of a number of studies of alpha-lipoic acid in people with diabetic nerve disease. The study found that 53 percent of patients on alpha-lipoic acid versus 37 percent on a placebo had improved scores in their symptoms.

      • The NATHAN I (Neurological Assessment of Thioctic Acid in Neuropathy) trial is an ongoing, long-term, multi-center trial in North America and Europe that is assessing the role of alpha-lipoic acid given orally for the prevention and treatment of diabetic neuropathy. A follow-up study called NATHAN II is currently investigating alpha-lipoic acid for relief of painful neuropathy symptoms, but as of this printing, the results have not yet been published.

      SIDE EFFECTS AND DRUG INTERACTIONS

      To date, no serious side effects from alpha-lipoic acid have been reported, even though it has been used intravenously and in long-term trials. However, you may experience allergic reactions if you take alpha-lipoic acid. Alpha-lipoic acid may cause nausea and vomiting, as well as vertigo.

      Anecdotal information indicates that alpha-lipoic acid may affect the thyroid, so ask your doctor whether you should have your thyroid levels tested. Studies in animals have shown that high doses of alpha-lipoic acid can be harmful when a thiamine deficiency is present. Ask your doctor about this side effect, particularly if you regularly drink large quantities of alcohol and may thus be thiamine-deficient. Your doctor may recommend that you take thiamine supplements; but ask your doctor first. Some anecdotal reports indicate that alpha-lipoic acid or other antioxidants may decrease the beneficial effects of chemotherapy, so also discuss this side effect with your doctor.

      Monitor your blood glucose closely when taking alpha- lipoic acid and diabetes medications such as sulfonylureas. Low blood glucose can occur. In addition, you should not take alpha-lipoic acid and antacids at the same time because your body may not absorb the alpha-lipoic acid properly. Instead, space these medications a few hours apart.

      OTHER NAMES • Queen’s Crape Myrtle • Queen’s Flower • Pride of India •

BANABA

       Lagerstroemia speciosa

      Banaba is a type of crape myrtle that grows in the Philippines, India, Malaysia, and Australia. This tropical, flowering tree has bright pink to purple blooms that give way to nut-like fruits. Its leathery leaves turn red-orange in the fall. As part of folk medicine in the Philippines, banaba leaves are used to make a tea to treat diabetes.

      USES

      Recently, banaba has become popular in the United States as treatment for type 2 diabetes. Its leaves are used to make an oral form of the supplement, found as a single ingredient or as one of several ingredients in dietary supplements. Banaba’s active ingredients are thought to stimulate cells to take up glucose and work similarly to insulin.

      However, banaba’s effect on blood glucose has not been confirmed in large, rigorous, long-term studies. Its effect on A1C, a measure of average blood glucose over 3 months, has never been reported. No information on its long-term use in people is available.

      Banaba is used in multi-ingredient products for weight loss, though it has never been studied for this purpose in humans. Its potential for weight loss is based on studies in animals.

      Banaba leaves are also used as a diuretic and purgative (used to empty the bowels) supplement. Its roots are used to treat upset stomach.

      DOSE

      In studies, scientists have used banaba in doses of 16–48 mg daily. The most effective dose in one small study was a daily 48-mg soft-gel capsule containing 1% corsolic acid.

      STUDIES

      One very small One very small study indicates that banaba may be helpful in lowering blood glucose in those with type 2 diabetes. However, the authors only reported percentage lowering of blood glucose and did not report the actual values.

      • The study examined 10 patients with type 2 diabetes who took three different doses of banaba (16, 32, or 48 mg) in soft-or hard-gel capsules for 15 days. The patients stopped taking their regular diabetes medications 45 days before the study. At the end of the study, the patients taking the 32-and 48-mg soft gels showed an 11% and 30% decrease, respectively, in their basal blood glucose values. In addition, patients