Fenugreek: A Noteworthy Hypoglycemic
by Lyra Heller, MA
Today, according to the World Health Organization (WHO), at least 30 million people worldwide, and an estimated 16 million people in America, suffer from diabetes mellitus, a chronic disorder characterized by high blood sugar and abnormal metabolism of carbohydrates, fats and protein. They are marked by increases in thirst (polydispsia), appetite (polyphagia) with over eating, volume of urine (polyuria) triggering increased urination, sweet tasting urine (glycosuria), fatigue, weight loss, muscle cramps, impaired vision, poor wound healing, increased risk to infection, and, in women, itching due to vaginal yeast infection. Diabetes, the seventh leading cause of death in the United States, can go undiagnosed until one of its life-threatening complications develops. About 85 percent of all diabetics develop retinopathy, 25-50 percent develop kidney disease, and 60-70 percent have mild to severe forms of nerve damage. Diabetics are also two to four times more likely to develop cardiovascular disease and two to four times more likely to suffer a stroke.
While the tendency to develop diabetes is strongly hereditary, there is believed to be an environmental component yet to be fully identified that triggers its development in susceptible individuals. Lack of exercise and obesity are considered major contributors to Type II diabetes; roughly 90 percent of individuals with NIDDM are obese. Obesity predisposes one to the condition of insulin resistance, which is characterized by the hyper-secretion of insulin (hyperinsulinemia). Increased insulin resistance results in increased fasting and postprandial beta cell synthesis, which leads to "beta cell burnout" and, eventually, diabetes. The condition of insulin resistance may exist for many years before pancreatic beta cell function actually becomes impaired. In addition to diabetes, insulin resistance and the resultant hyperinsulinemia are associated with an increased risk for coronary artery disease, hypertension, and high blood pressure.
The increased risk of developing pathological complications associated with diabetes is directly related to a condition of mildly elevated hyperglycemia. Chronic elevations in blood sugar levels contribute to the formation of advanced glycation end products (AGEs), which result from the nonenzymatic glycosylation of proteins, and to the formation of sugar alcohols. The formation of both AGEs and sugar alcohols is associated with long-term pathology of the nerves, blood vessels, kidney, lens, and pancreas, and in general contribute to the aging process. Sugar alcohol formation in particular is directly involved in cataract development and loss of nervous function. Maintaining blood glucose homeostasis is therefore critical for preserving the health of the patient and reducing the risk of associated pathological disease.
Side effects range from hypoglycemia to lactic acidosis, kidney and cardiovascular damage. The sulphonylureas sensitize the beta cells in the islets of Langerhans in the pancreas to glucose, resulting in enhanced internal secretion of insulin and the simultaneous suppression of glucose production in the liver. Hypoglycemia occurs with individuals on a lowered calorie intake, those who are generally weak and debilitated or have kidney impairment. Biguanides prevent synthesis of glucose by the liver and produce mild impairment of intestinal glucose absorption stimulating lactic acidosis and gastrointestinal disturbances. Biguanides are contraindicated in persons with hepatic and kidney dysfunction and cardiac failure. Acarbose, a competitive inhibitor of intestinal (-glucosidases, acts by delaYing carbohydrate digestion and slowing down carbohydrate absorption. Again, side effects associated with low blood sugar (hypoglycemia) are an outcome. Finally, Troglitazone was developed to reduce insulin resistance. These modern strategies involving synthetic oral hypoglycemics may be effective in controlling blood glucose levels, but they are insufficient to prevent all the complications listed above. Safer alternatives rooted in dietary and herbal remedies are very desirable and available.
Managing Diabetes with Hypoglycemic Botanicals
In every historic instance where symptoms associated with diabetes were recognized, herbal strategies were documented. TCM, in particular, illustrates how specific plants were classified and identified as useful for the treatment of symptoms associated with elevated blood sugar (See Table 1). The Ayurvedic, Unani and folkloric medical traditions of the Indian subcontinent also contribute an extensive indigenous hypoglycemic botanical pharmacy. Marles and Farnsworth recently summarized screens studYing the blood glucose lowering activity of 582 traditionally used plants. Two hundred and ninety five plants were used for the symptoms of diabetes. Eighty-one percent of the 295 plants tested gave positive results. Seventeen of the most widely used traditional anti-diabetic plants, in addition to many others, are used in India. (See Table 2.)
This high percentage of active herbs suggests a large variety of active constituents and mechanisms of action with regard to the control of blood sugar. At the cellular and molecular levels, plants and animals are not very different in their metabolic processes. Glucose is the metabolic energy source and most important biosynthetic precursor in plants, so glucose undergoes storage and mobilization under hormonal control in plants as it does in animals. Plant metabolism-regulating constituents can also be animal metabolism-regulating agents. In the human body, blood sugar is tightly regulated under the coordinated effort of endocrine pancreatic and hepatic functions in an effort to maintain a dynamic equilibrium stimulated by continuous fluctuations in blood sugar. The pancreatic hormones, insulin, glucagon and somatostatin act as messengers to maintain normal fasting blood sugar levels in the range of 75-115 mg/dl (milligrams per deciliter of blood) and postprandial levels not to register an increase exceeding 180 mg/dl. There are multiple mechanisms of action in place that regulate blood glucose similar to those in plants. The diversity of active constituents elaborated by hypoglycemic plants may very well provide the therapy of choice for NIDDM.
Based on these screenings, there are many plants to explore that offer potential as blood sugar regulators. A high priority candidate might conform to the following criteria:
While TCM is adept at the management of diabetic symptoms, fenugreek seed, Hu-lu-pa (Trigonella foenum-graecum, Fabaceae) appears under-utilized for its hypoglycemic properties. This is an abundant botanical, extremely safe, available and inexpensive. Based on historical use in both Ayurveda and TCM and experimental studies in India, fenugreek seed fulfills all the criteria of a high priority herb worthy of extensive clinical application. Used alone as a decoction, added to curry and stews, consumed in raw powdered form or taken as a dry powdered concentrate in capsules or tablets, fenugreek is a welcome addition to the natural pharmacies of all medical herbalists seeking alternative therapies for diabetes.
An Egyptian preparation called Helba was prepared by soaking the seeds in water till they would swell into a thick paste. This paste preparation, or a decoction of the same, would comfort the stomach, soothe inflamed intestines and be used for diabetes. In India, the seeds are eaten boiled or roasted as a vegetable for dyspepsia, diarrhea, dysentery, colic, flatulence, rheumatism, enlargement of the liver and spleen and for chronic cough.
Fenugreek seeds Hu-lu-pa first appeared in the Chia yu pen tsao during the Sung Dynasty (AD 1057). It is described as bitter in flavor possessing very warming properties. Fenugreek enters the Kidney channel, warms the Kidney Yang and dispels Cold-damp. Hsu describes its clinical applications as follows: "Íhernia due to cold-chi, abdominal and costal distention, beriberi due to cold-dampness, cold pain in the lower abdomen and impotence." The therapeutic dose ranges from 2.5 to 6 grams daily.
Recently, several studies have demonstrated hypoglycemic properties of fenugreek seeds in both animals and humans, thus lending support to its traditional use. Research further suggests that fenugreek has a lowering effect on plasma cholesterol and triglyceride levels.
The hypoglycemic effect of fenugreek is thought to be largely due to its high content of soluble fiber, which acts to decrease the rate of gastric emptYing thereby delaYing the absorption of glucose from the small intestine. Also, fiber in general (except for cellulose) enhances fecal excretion of bile acids and cholesterol, which would explain in part fenugreek's hypocholesterolemic properties.
The defatted fraction of fenugreek in particular has been shown to lower basal blood glucose levels, plasma glucagon and somatostatin levels, and reduces orally induced hyperglycemia in normal dogs. While it is believed that the soluble fiber portion of fenugreek is largely responsible for its effects on lowering postprandial blood glucose levels, it is likely that other factors contribute to fenugreek's anti-diabetic properties as well. For instance, it has been suggested that a specific amino acid, hydroxyisoleucine, which represents 80 percent of the free amino acids in fenugreek seeds, may possess insulin-stimulating properties. Fenugreek also contains compounds like trigonelline and coumarin with reported hypoglycemic properties.
In another study, the administration of defatted fenugreek seed powder (100 g divided into two equal doses for 10 days) to insulin-dependent diabetics, resulted in significantly reduced fasting blood sugar and improved glucose tolerance test results. Additionally, there was a 54 percent reduction in 24 hour urinary glucose excretion as well as a significant reduction in cholesterol and triglycerides levels.
Similar improvements in glucose tolerance were reported in both normal and Type II diabetics following fenugreek therapy. In patients with Type II diabetes, fasting blood glucose, 24-hour urinary glucose output, and serum cholesterol were significantly reduced following continued therapy (25 g per day of unprocessed seed for 21 days). In addition, the authors noted that insulin requirements for two Type II patients on insulin were reduced from 56 units/day to 20 units/day. The investigators speculate that the fenugreek seeds may help to improve insulin sensitivity, which is presumed to be due to the effects of fiber. The soluble fiber contained in the mucilage slows carbohydrate metabolism resulting in reduced insulin levels and lowered blood glucose. Interestingly, dietary fiber does not have to be concurrently administered with a meal in order to produce a beneficial effect on glucose tolerance. It appears that individuals may develop improved insulin sensitivity with the regular consumption of fiber from other sources, like flax seeds.
Fenugreek Considerations and Safety
A word on the issue of herb-drug interaction is important. The simultaneous use of fenugreek or any natural botanical hypoglycemic given in concentrated or extract form with anti-diabetic drugs requires careful monitoring by the patient, physician and doctor of Oriental medicine. Botanical hypoglycemics like fenugreek seeds offer a safe management tool. When fenugreek is administered at the correct dose, dependency on a synthetic drug or combination of drugs may decline. Direct communication with the primary care physician is essential not only to protect the patient, but also to educate the physician about legitimate safe alternatives to synthetic drugs.
A recent article published in the Archives of Internal Medicine, entitled "Herbal Medicinals, Selected Clinical Considerations Focusing On Known or Potential Drug-Herb Interactions" demonstrates several important trends and speaks to the issue of fenugreek and botanical medicine in general. First, there is growing concern and acknowledgement on the part of conventional physicians regarding undisclosed patient use of herbs with prescription medications as contributing to potential adverse reactions. Second, physicians are uninformed and ambivalent about the efficacy and safety of plant drugs whether given singly, or in combination. Third, physicians will come to rely on articles such as this as the gospel, even though the information may be suspect because the author is not an herbalist or a pharmacognocist with a sympathetic eye for traditional medical systems. Fourth, physicians, in the absence of balanced reporting on the health benefits and safety of herbs by a panel of botanical experts from a variety of backgrounds, will continue to choose synthetics drugs when there may be no need. Consider this quote: "Numerous herbal medicinals have been shown to effect blood glucose levels including chromium, fenugreek, garlic, ginger, ginseng, Gymnema sylvestre, nettle and sage for patients with hypoglycemia and devil's claw, ginseng, licorice and ma huang for patients with hyperglycemia." This section on potential hypoglycemic herb-drug interactions demonstrates the need for doctors to be in continuous open dialogue with professional herbalists if botanical medicine is to prosper in the years to come and dependency on prescription drugs is to decline. Clearly the herbs used to treat hypoglycemia are, in fact, known botanical hypoglycemics. And, chromium is not an herb.