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

also include a washout, since this allows time for the first treatment to be cleared from the body. If patients are “crossed- over” directly (without a “washout”), then the first medication or supplement may still be in the body, and the results may be falsely influenced by the treatment that is still in the body.

      “Statistically significant” or “significant results”: These are mathematically analyzed results that are meaningful. For instance, a supplement may decrease blood glucose, but the results may not be statistically significant. Thus, even though the product has shown some benefit, the results are not strong enough or “significant” enough to justify taking the product. The opposite is also true—although sometimes the results are statistically significant, they are not enough to get a patient to his or her desired goals. For instance, a product may decrease fasting glucose “significantly” from 250 to 200 mg/dl, but the results are not at the desired goal of 70–130 mg/dl.

      Participants: When determining the merit of a study or trial, it is also important to consider the participants. This information is almost never reported in major media coverage of trials, but can usually be found in the original published reports or with a little digging on the Internet. Factors to consider include:

      • Who were the patients that participated? Were they healthy or did they actually have the disease that was being studied? A study focused on a blood glucose treatment but filled with non-diabetes participants would be less useful than the same study using people with diabetes.

      • What were the characteristics of the patients at the start of the clinical trial? The patients in each group should have similar characteristics (for instance, age, health status, gender, or ethnicity) at the beginning of a well-run clinical trial. Differences in characteristics at the start could potentially affect the results, making the findings potentially less trustworthy.

      • How many patients dropped out? If there is a difference between the study groups due to dropouts, then perhaps there could be a problem. For instance, if many people dropped out of the treatment group but the results are very favorable in that group, then the results may be suspicious because the sample size is smaller and people who responded negatively may not be represented in the final findings.

      While there are many more terms, methods, and definitions associated with clinical studies, this list should cover most of what is discussed in the following text. Most important is that you remain vigilant as a consumer of medications and supplements. When you learn the results of a study, you should also learn how the study was conducted before making a decision. Search out literature on clinical trials and studies, and discuss studies with your doctor or pharmacist.

PART II SUPPLEMENTS

      OTHER NAMES • Burn Plan • Lily of the Desert • • Elephant’s Gall • Sábila •

ALOE

       Aloe vera

      This succulent, green tropical plant has been used in medicine for thousands of years. Aloe is pictured on the walls of ancient Egyptian temples and discussed for its medicinal properties in the Egyptian Book of Remedies from the 16th century. Derived from the Arabic alloeh, the name means “bitter and shiny substance.” The plant thrives in warm climates such as the Mediterranean and Caribbean, as well as areas of Africa and North and South America. Aloe is just one of 400 species of aloe plants.

      USES

      Uses Patients are probably most familiar with aloe gel to treat sunburns, skin abrasions, and dry skin. However, aloe gel, which comes from the plant’s leaves, is also the most common form used to treat diabetes. Aloe is popular among Hispanic patients and is known as sábila .

      Aloe is taken by mouth to treat type 2 diabetes. It is found in many formulations such as beverage mixtures or tablets. The gel’s active ingredients include polysaccharides and glycoprotein. They are thought to stimulate the body’s ability to transport excess glucose from the blood into cells and tissues where it is needed. Some scientists suspect that the high fiber content of the gel itself may promote the body to use glucose more effectively. Nonetheless, aloe’s effect on blood glucose has not been confirmed in large, rigorous, long-term studies.

      Aloe latex is another form of aloe. It has a laxative effect and can be taken as a juice or dried and taken as a tablet. It is not used to treat diabetes.

      DOSE

      There is no recommended There is no recommended dose, since necessary dose-finding studies have not been conducted.

      STUDIES

      Three small studies have indicated that aloe may decrease blood glucose. It may also decrease triglycerides but not total cholesterol.

      • A study of five patients with type 2 diabetes who took one- half teaspoon of aloe sap twice daily found that average blood glucose decreased. But the study was very small and did not include control subjects (i.e., patients who did not take aloe).

      • A small study of 40 patients with type 2 diabetes who took one tablespoon of aloe gel or a placebo (“dummy gel”) twice a day for 6 weeks found that fasting blood glucose decreased significantly in the aloe group. Triglyceride levels also decreased, but not overall cholesterol.

      • In another small study of 40 patients with type 2 diabetes, scientists found that adding one tablespoon of aloe gel to the diabetes medication glyburide (a sulfonylurea) twice a day for 6 weeks significantly decreased fasting blood glucose. Triglyceride levels also decreased, but not overall cholesterol.

      SIDE EFFECTS AND DRUG INTERACTIONS

      There are many theoretical adverse effects of aloe. Patients should be cautious about low blood glucose when taking aloe in addition to diabetes medications such as insulin, sulfonylureas, and others.

      In addition, patients should be cautious that an aloe product could be inadvertently contaminated with other parts of the plant that cause a laxative effect. For example, an ingredient found in aloe called anthraquinones was once included in over- the-counter laxatives. The FDA had concerns about fluid and electrolyte loss and had requested that manufacturers conduct further safety studies. Due to the excessive costs necessary to conduct these tests, manufacturers chose not to do the tests, and aloe is no longer allowed in nonprescription laxatives.

      There are anecdotal reports of liver and kidney problems with high doses of aloe. Aloe should not be used by pregnant or breastfeeding women. There is concern that use during pregnancy may result in miscarriage and that some toxic substances may pass to the infant in breast milk.

      There is the potential for prolonged bleeding when aloe is used with the anesthetic sevoflurane during surgery. Thus, aloe use should be stopped two weeks before surgery. Aloe should not be used with drugs that deplete potassium, such as certain diuretics. It should not be taken with the heart medication digoxin, since low potassium may result in dangerously high concentrations of digoxin.

      OTHER NAMES • Thioctic Acid •

ALPHA-LIPOIC ACID

      Alpha-lipoic acid is a vitamin-like substance called an antioxidant—a substance that protects cells from the damaging effects of oxidative stress. Scientists theorize that oxidative stress can lead to diseases such as cancer, heart disease, and diabetes. Alpha-lipoic acid is produced in the liver. In addition, alpha-lipoic acid is found in foods like broccoli, spinach, potatoes, yeast, and animal liver. In the laboratory, scientists can synthesize alpha-lipoic acid, which can then be given as an injection or formulated into tablets or capsules.

      USES

      People with diabetes use alpha-lipoic acid to treat nerve damage to the hands and feet (called peripheral neuropathy). This painful nerve condition can cause various symptoms such as burning