Alpha-Lipoic Acid

Overview

Alpha lipoic acid is a sulfur-containing fatty acid compound found in the mitochondria – the energy producing structures found in our cells. As a dietary supplement, alpha-lipoic acid (also known as lipoic acid and thioctic acid) may act as a powerful antioxidant, where it may work in synergy with other nutritional antioxidants like vitamins C and E to help prevent cellular damage from free radicals. Alpha-lipoic acid has also been shown to help control blood sugar levels in patients with diabetes.

Although alpha lipoic acid is involved in cellular energy production, its chief role as a dietary supplement may be as a powerful antioxidant. The body appears to be able to manufacture enough alpha-lipoic acid for its metabolic functions (as a co-factor for a number of enzymes involved in converting fat and sugar to energy), but the excess levels provided by supplements allow alpha-lipoic acid to circulate in a “free” state (outside of the cells where it is usually found). In this state, alpha-lipoic acid has functions as both a water- and fat-soluble antioxidant. This unique ability of alpha-lipoic acid to be active in both water and lipid compartments of the body is important because most antioxidants, such as vitamins C and E, are effective in only one area or the other. For instance vitamin C is usually restricted to the interior compartment of cells and the aqueous (“watery”) portion of blood, while vitamin E embeds itself in the lipid (“fatty”) portion of cell membranes. Adding to the potential importance of alpha-lipoic acid is its role in the production of glutathione, one of the chief cellular antioxidants produced directly by the body.

Comments

If alpha-lipoic acid were just another antioxidant, then its value would be far less. After all, there are dozens of ingredients on the market that have powerful antioxidant functions. The unique qualities possessed by alpha-lipoic acid, functioning as both a water- and fat-soluble antioxidant as well as its role in increasing the overall function of other dietary antioxidants, make it an intriguing supplement worthy of serious consideration – especially for people with diabetes because of its particular benefits in potentially preventing some forms of diabetic peripheral and autonomic neuropathy.

Scientific Support

In animal studies and human trials, alpha-lipoic acid supplementation has been shown to improve several indices of metabolic activity and lower the degree of oxidative stress (Androne et al. 2000, Arivazhagan et al. 2000). Alpha-lipoic acid supplementation may also help to reverse the decline in mitochondrial energy production that is commonly observed during the “normal” aging process (Ames 2003). Physical activity levels in animals can be increased by approximately 3-fold when supplemented with alpha-lipoic acid (Hagen et al. 1999), suggesting a beneficial effect on energy metabolism (Khanna et al. 1998). Levels of other antioxidants, such as glutathione and ascorbic acid, were also elevated in animals consuming alpha-lipoic acid, suggesting that the supplement may help protect and/or recycle these antioxidants and contribute to the overall capacity of the body to neutralize free radical damage (Packer et al. 1997, Packer et al. 1995).

In conjunction with other antioxidants, such as vitamin E, alpha-lipoic acid may be particularly helpful in patients with diabetes. By promoting the production of energy from fat and sugar in the mitochondria, glucose removal from the bloodstream may be enhanced and insulin function improved. Indeed, alpha-lipoic acid has been shown to decrease insulin resistance and is prescribed frequently in Europe as a treatment for peripheral neuropathy (nerve damage) associated with diabetes. In the U.S., the American Diabetes Association has suggested that alpha-lipoic acid plus vitamin E may be helpful in combating some of the health complications associated with diabetes, including heart disease, vision problems, nerve damage and kidney disease. Alpha-lipoic acid has also been implicated in helping to protect the brain from damage following a stroke.

There is a consistent body of evidence that intravenous infusions of alpha-lipoic acid are associated with a reduction in sensory symptoms of diabetic neuropathy (Ametov et al. 2003, Ziegler et al 2004) and that benefits are seen within 8-14 days of treatment on measures of pain, burning, numbness in patients receiving alpha-lipoic acid supplements. In human feeding studies (as opposed to studies of intravenous infusions of lipoic acid where most of the positive results exist for diabetic neuropathy), a handful of studies demonstrate that dietary supplementation with alpha-lipoic acid is able to help prevent hyperglycemia (Kinrad et al. 1999) and improve energetic substrates in muscle cells (Burke et al. 2003).

Safety / Dosage

Although there have been relatively few feeding studies conducted with alpha-lipoic acid in humans, it appears to be safe as a dietary supplement. Intakes of as much as 600mg per day have been used for treatment of diabetic neuropathy, with no serious side effects. General recommendations for antioxidant benefits typically call for 50 – 100mg per day as a general antioxidant, with higher levels of 300-600mg/day for preventing/treating complications of diabetes.

References

1.Ames BN. The metabolic tune-up: metabolic harmony and disease prevention. J Nutr. 2003 May;133(5 Suppl 1):1544S-8S.

2.Ametov AS, Barinov A, Dyck PJ, Hermann R, Kozlova N, Litchy WJ, Low PA, Nehrdich D, Novosadova M, O'Brien PC, Reljanovic M, Samigullin R, Schuette K, Strokov I, Tritschler HJ, Wessel K, Yakhno N, Ziegler D; SYDNEY Trial Study Group. The sensory symptoms of diabetic polyneuropathy are improved with alpha-lipoic acid: the SYDNEY trial. Diabetes Care. 2003 Mar;26(3):770-6.

3.Androne L, Gavan NA, Veresiu IA, Orasan R. In vivo effect of lipoic acid on lipid peroxidation in patients with diabetic neuropathy. In Vivo. 2000 Mar-Apr;14(2):327-30.

4.Arivazhagan P, Panneerselvam C. Effect of DL - alpha -lipoic acid on neural antioxidants in aged rats. Pharmacol Res. 2000 Sep;42(3):219-22.

5.Gualandri W, Gualandri L, Demartini G, Esposti R, Marthyn P, Volonte S, Stangoni L, Borgonovo M, Fraschini F. Redox balance in patients with Down's syndrome before and after dietary supplementation with alpha-lipoic acid and L-cysteine. Int J Clin Pharmacol Res. 2003;23(1):23-30.

6.Haak E, Usadel KH, Kusterer K, Amini P, Frommeyer R, Tritschler HJ, Haak T. Effects of alpha-lipoic acid on microcirculation in patients with peripheral diabetic neuropathy. Exp Clin Endocrinol Diabetes. 2000;108(3):168-74.

7.Hagen TM, Ingersoll RT, Lykkesfeldt J, Liu J, Wehr CM, Vinarsky V, Bartholomew JC, Ames AB. (R)-alpha-lipoic acid-supplemented old rats have improved mitochondrial function, decreased oxidative damage, and increased metabolic rate. FASEB J. 1999 Feb;13(2):411-8.

8.Jacob S, Ruus P, Hermann R, Tritschler HJ, Maerker E, Renn W, Augustin HJ, Dietze GJ, Rett K. Oral administration of RAC-alpha-lipoic acid modulates insulin sensitivity in patients with type-2 diabetes mellitus: a placebo-controlled pilot trial. Free Radic Biol Med. 1999 Aug;27(3-4):309-14.

9.Khanna S, Atalay M, Lodge JK, Laaksonen DE, Roy S, Hanninen O, Packer L, Sen CK. Skeletal muscle and liver lipoyllysine content in response to exercise, training and dietary alpha-lipoic acid supplementation. Biochem Mol Biol Int. 1998 Oct;46(2):297-306.

10.Konrad T, Vicini P, Kusterer K, Hoflich A, Assadkhani A, Bohles HJ, Sewell A, Tritschler HJ, Cobelli C, Usadel KH. alpha-Lipoic acid treatment decreases serum lactate and pyruvate concentrations and improves glucose effectiveness in lean and obese patients with type 2 diabetes. Diabetes Care. 1999 Feb;22(2):280-7.

11.Marriage B, Clandinin MT, Glerum DM. Nutritional cofactor treatment in mitochondrial disorders. J Am Diet Assoc. 2003 Aug;103(8):1029-38.

12.Miquel J. Can antioxidant diet supplementation protect against age-related mitochondrial damage? Ann N Y Acad Sci. 2002 Apr;959:508-16.

13.Morcos M, Borcea V, Isermann B, Gehrke S, Ehret T, Henkels M, Schiekofer S, Hofmann M, Amiral J, Tritschler H, Ziegler R, Wahl P, Nawroth PP. Effect of alpha-lipoic acid on the progression of endothelial cell damage and albuminuria in patients with diabetes mellitus: an exploratory study. Diabetes Res Clin Pract. 2001 Jun;52(3):175-83.

14.Nickander KK, McPhee BR, Low PA, Tritschler H. Alpha-lipoic acid: antioxidant potency against lipid peroxidation of neural tissues in vitro and implications for diabetic neuropathy. Free Radic Biol Med. 1996;21(5):631-9.

15.Packer L, Tritschler HJ, Wessel K. Neuroprotection by the metabolic antioxidant alpha-lipoic acid. Free Radic Biol Med. 1997;22(1-2):359-78.

16.Packer L, Witt EH, Tritschler HJ. alpha-Lipoic acid as a biological antioxidant. Free Radic Biol Med. 1995 Aug;19(2):227-50.

17.Podda M, Tritschler HJ, Ulrich H, Packer L. Alpha-lipoic acid supplementation prevents symptoms of vitamin E deficiency. Biochem Biophys Res Commun. 1994 Oct 14;204(1):98-104.

18.Roy S, Sen CK, Tritschler HJ, Packer L. Modulation of cellular reducing equivalent homeostasis by alpha-lipoic acid. Mechanisms and implications for diabetes and ischemic injury. Biochem Pharmacol. 1997 Feb 7;53(3):393-9.

19.Ruhe RC, McDonald RB. Use of antioxidant nutrients in the prevention and treatment of type 2 diabetes. J Am Coll Nutr. 2001 Oct;20(5 Suppl):363S-369S.

20.Ziegler D, Gries FA. Alpha-lipoic acid in the treatment of diabetic peripheral and cardiac autonomic neuropathy. Diabetes. 1997 Sep;46 Suppl 2:S62-6.

21.Ziegler D, Hanefeld M, Ruhnau KJ, Hasche H, Lobisch M, Schutte K, Kerum G, Malessa R. Treatment of symptomatic diabetic polyneuropathy with the antioxidant alpha-lipoic acid: a 7-month multicenter randomized controlled trial (ALADIN III Study). ALADIN III Study Group. Alpha-Lipoic Acid in Diabetic Neuropathy. Diabetes Care. 1999 Aug;22(8):1296-301.

22.Ziegler D, Hanefeld M, Ruhnau KJ, Meissner HP, Lobisch M, Schutte K, Gries FA. Treatment of symptomatic diabetic peripheral neuropathy with the anti-oxidant alpha-lipoic acid. A 3-week multicentre randomized controlled trial (ALADIN Study). Diabetologia. 1995 Dec;38(12):1425-33.

23.Ziegler D, Nowak H, Kempler P, Vargha P, Low PA. Treatment of symptomatic diabetic polyneuropathy with the antioxidant alpha-lipoic acid: a meta-analysis. Diabet Med. 2004 Feb;21(2):114-21.

24.Ziegler D, Reljanovic M, Mehnert H, Gries FA. Alpha-lipoic acid in the treatment of diabetic polyneuropathy in Germany: current evidence from clinical trials. Exp Clin Endocrinol Diabetes. 1999;107(7):421-30.

EDITOR'S NOTE: This monograph can be found in The Health Professional's Guide to Dietary Supplements (Lippincott, Williams & Wilkins) by Shawn M. Talbott, PhD and Kerry Hughes, MS

Banaba

Overview

Banaba (Lagerstroemia speciosa) is a traditional medicine from India, Southeast Asia and the Philippines that has been used for lowering the blood sugar and for diabetes. The main active component in banaba has been thought to be corosolic acid, and typical formulations on the market are standardized to 1% corosolic acid. Recent research has found another compound called lagerstroemin, an ellagitannin, that is able to cause insulin-like activity (Hattori et al., 2003; Hayashi et al., 2002). In animal studies and unpublished studies in humans banaba has been found to not only regulate blood sugar, but to have the “side effect” of weight loss without dietary alterations (Suzuki et al., 1999). One hypothesis for this is lower fluctuations in blood sugar, and thus lower food cravings (for carbohydrates) which may result in moderate weight loss.

Comments

Although published clinical studies are still lacking for banaba, the animal studies have shown good promise that this herbal medicine might be used to lower blood sugar levels in hyperglycermic states and diabetes (Liu et al., 2001; Kakuda et al., 1996; Murakami et al., 1993).

Scientific Support

Banaba was studied in a randomized clinical trial for its effect on blood glucose levels in Type II diabetics. A standardized extract of banaba (Lagerstroemia speciosa standardized to 1% corosolic acid; of the brand “Glucosol”) was administered for two weeks, in two different preparations: a softgel, and a dry-powder hard gelatin capsule formulation. Significant reductions in blood glucose levels were found at daily dosages of 32 and 48 mg from banaba administration, and the softgel preparation showed a larger (30% vs. 20%) decrease in blood glucose, indicating a higher bioavailability in the softgel preparation (Judy et al, 2003).

Safety / Dosage

At the recommended dosages of 8-48 mg daily, no side effects have been found for banaba. However, at higher dosages symptoms associated with low blood sugar (headache, dizziness, fatique) may be expected.

References

1.Hattori K, Sukenobu N, Sasaki T, Takasuga S, Hayashi T, Kasai R, Yamasaki K, Hazeki O. Activation of insulin receptors by lagerstroemin. J Pharmacol Sci. 2003 Sep;93(1):69-73.

2.Hayashi T, Maruyama H, Kasai R, Hattori K, Takasuga S, Hazeki O, Yamasaki K, Tanaka T. Ellagitannins from Lagerstroemia speciosa as activators of glucose transport in fat cells. Planta Med. 2002 Feb;68(2):173-5.

3.Judy WV, Hari SP, Stogsdill WW, Judy JS, Naguib YM, Passwater R. Antidiabetic activity of a standardized extract (Glucosol) from Lagerstroemia speciosa leaves in Type II diabetics. A dose-dependence study. J Ethnopharmacol. 2003 Jul;87(1):115-7.

4.Kakuda T, Sakane I, Takihara T, Ozaki Y, Takeuchi H, Kuroyanagi M. Hypoglycemic effect of extracts from Lagerstroemia speciosa L. leaves in genetically diabetic KK-AY mice. Biosci Biotechnol Biochem. 1996 Feb;60(2):204-8.

5.Liu F, Kim J, Li Y, Liu X, Li J, Chen X. An extract of Lagerstroemia speciosa L. has insulin-like glucose uptake-stimulatory and adipocyte differentiation-inhibitory activities in 3T3-L1 cells. J Nutr. 2001 Sep;131(9):2242-7.

6.Murakami C, Myoga K, Kasai R, Ohtani K, Kurokawa T, Ishibashi S, Dayrit F, Padolina WG, Yamasaki K. Screening of plant constituents for effect on glucose transport activity in Ehrlich ascites tumour cells. Chem Pharm Bull (Tokyo). 1993 Dec;41(12):2129-31.

7.Suzuki Y, Unno T, Ushitani M, Hayashi K, Kakuda T. Antiobesity activity of extracts from Lagerstroemia speciosa L. leaves on female KK-Ay mice. J Nutr Sci Vitaminol (Tokyo). 1999 Dec;45(6):791-5.

EDITOR'S NOTE: This monograph can be found in The Health Professional's Guide to Dietary Supplements (Lippincott, Williams & Wilkins) by Shawn M. Talbott, PhD and Kerry Hughes, MS

Chromium

Overview

It is estimated that 90% of American diets are deficient in chromium, and the general population is thought to show signs of a marginal deficiencies, such as impaired glucose tolerance. Typical food sources of chromium include brewer’s yeast, whole grain cereals, broccoli, prunes, mushrooms and beer. However, the typical American diet is thought to exacerbate the problem of deficiency by the large-scale consumption of simple sugars in processed foods that may block chromium absorption. Brewer’s yeast, also called nutritional yeast, is thought to be the most bioavailable form of chromium, as it part of a bioactive complex called glucose tolerance factor (GTF) (Sterns et al., 1995).

Chromium is one of the essential trace minerals, and is important for carbohydrate metabolism and the potentiation of insulin. As chromium is well known for its difficulty in absorption, with only about 3% of the chromium we intake being absorbed, supplementation is a viable option. However, there are many types of chromium supplements on the market, and there have been recent concerns over the potential for toxicity of chromium picolinate, one of the most studied supplemental forms of chromium. These concerns have not been validated. Chromium chloride as well as some other forms of chromium (III) supplements do not have this concern (Vincent, 2000; Vincent 2003).

Comments

Although evidence is still mounting for the use of chromium to normalize blood sugar and meet marginal deficiencies, there seems to be a great potential as a supplement as the American population is sorely in need of nutritional answers to its large and growing overweight and diabetic populations.

Scientific Support

Athletic Performance

Chromium’s clinical results so far for enhancing exercise performance have been limited. In a double-blind clinical study on the effects of chromium picolinate supplementation on football players, 200 mcg daily was administered. The outcome measurements were urinary excretion, girth and skinfold measures, percent body fat, lean body mass, and isometric and dynamic strength. No changes in any of the parameters were found, except for an increase in urinary chromium output (Clancy et al., 1994).

In two earlier studies, 200 mcg daily of chromium supplementation failed to show results. One study involved college students during weight training, and the only group that showed a significant difference were the females, who had a significant increase in body weight (Hasten et al., 1992). In another double-blind placebo controlled study, no enhancement on athletic performance was found (Walker et al., 2000).

Weight Loss

Mixed results have been found clinically for chromium picolinate in weight loss. Pittler et al. (2003) performed a meta-analysis of chromium as it had been administered in randomized, double-blind, placebo controlled studies that reported on chromium picolinate’s use in weight loss. Ten studies matched the criteria of the meta-analysis, and the authors found a small benefit for the use of chromium picolinate in weight loss.

Volpe et al. (2001) tested the effects of chromium picolinate supplementation on body composition, resting metabolic rate, and zinc status in moderately obese women who underwent a prescribed exercise program. No changes in any of the measured outcomes were found except for a reduction in serum total cholesterol levels and total iron building capacity in both groups due to the increase in exercise for both groups.

In a clinical study on the effects of chromium picolinate supplementation on the risk factors for coronary artery disease and type II diabetes in obese women, 400 mcg daily was administered. In the groups that underwent exercise, chromium supplementation resulted in significant weight loss, whereas, the groups that did not undergo exercise but used chromium has significant weight gain. Chromium supplementation was only recommended then by the authors for obese women who were undergoing an exercise program (Grant et al., 1997).

In an earlier double-blind, placebo controlled study, chromium picolinate (400 mcg daily) supplementation was administered and investigated for its effect on body composition in obese people undergoing and exercise program. The results of this study showed no difference between the placebo and chromium groups (Trent et al., 1995).

Blood Sugar Control/ Diabetes & Chromium Ions

Ryan et al. (2003) performed a review of chromium (III) supplements for diabetes type II and hyperlipidemia. It was found that chromium reduced blood glucose in hyperglycemia, but not in people with normal blood glucose levels. Chromium was found to have variable effects on lipid levels.

In another recent study, Keszthelyi et al. (2003) found chromium supplementation used in diabetics for 6 months resulted in significant reductions in cholesterin levels, as well as a slight reduction in the HbA1c level.

Anderson et al. (2001) studied the effect of combined and individual zinc and chromium supplementation on oxidative stress and glucose homeostasis in people with type II diabetes. Diabetic subjects were supplemented with 30 mg/day of zinc (as zinc gluconate), or 400 micrograms/day of chromium (as chromium picolinate), or the combination, or placebo. The authors concluded that there are potential beneficial antioxidant effects of taking either the individual or combined supplementation of zinc or chromium in type II diabetics.

Bahijri (2000) found an improved lipid profile and glycemic control in a study on healthy adults given chromium tetrachloride daily. In this double-blind study, 200 micrograms or placebo was given daily for 8 weeks.

In a general study of urine and serum concentrations in diabetic and normal subjects, Ding et al. (1998) found that chromium loss is associated with aging and also diabetes occurrence.

Chromium supplementation on diabetic patients (with type I and type II diabetes) was investigated. Chromium supplementation (200 mcg daily) produced beneficial results in reducing insulin sulfonylurea or metformin requirements. Greater results were found for type II diabetics, but type I diabetics also showed good results with supplementation (Ravina and Slezack, 1993).

Safety / Dosage

The RDI for chromium is 120 mcg. There have been many concerns about the toxicity of chromium picolinate, however several recent studies have confirmed its safety (Campbell et al, 2004; Rhodes et al., 2005).

References

1.Anderson RA, Roussel AM, Zouari N, Mahjoub S, Matheau JM, Kerkeni A. Potential antioxidant effects of zinc and chromium supplementation in people with type 2 diabetes mellitus. J Am Coll Nutr. 2001 Jun;20(3):212-8.

2.Bahijri SM. Effect of chromium supplementation on glucose tolerance and lipid profile. Saudi Med J. 2000 Jan;21(1):45-50.

3.Campbell WW, Joseph LJ, Ostlund RE Jr, Anderson RA, Farrell PA, Evans WJ. Resistive training and chromium picolinate: effects on inositols and liver and kidney functions in older adults. Int J Sport Nutr Exerc Metab. 2004 Aug;14(4):430-42.

4.Clancy SP, Clarkson PM, DeCheke ME, Nosaka K, Freedson PS, Cunningham JJ, Valentine B. Effects of chromium picolinate supplementation on body composition, strength, and urinary chromium loss in football players. Int J Sport Nutr. 1994 Jun;4(2):142-53.

5.Ding W, Chai Z, Duan P, Feng W, Qian Q. Serum and urine chromium concentrations in elderly diabetics. Biol Trace Elem Res. 1998 Sep;63(3):231-7.

6.Grant KE, Chandler RM, Castle AL, Ivy JL. Chromium and exercise training: effect on obese women. Med Sci Sports Exerc. 1997 Aug;29(8):992-8.

7.Hasten DL, Rome EP, Franks BD, Hegsted M. Effects of chromium picolinate on beginning weight training students. Int J Sport Nutr. 1992 Dec;2(4):343-50.

8.Keszthelyi Z, Past T, Koltai K, Szabo L, Mozsik G. Chromium (III)-ion enhances the utilization of glucose in type-2 diabetes mellitus. Orv Hetil. 2003 Oct 19;144(42):2073-6.

9.Pittler MH, Stevinson C, Ernst E. Chromium picolinate for reducing body weight: meta-analysis of randomized trials. Int J Obes Relat Metab Disord. 2003 Apr;27(4):522-9.

10.Ravina A, Slezack L. Chromium in the treatment of clinical diabetes mellitus. Harefuah. 1993 Sep;125(5-6):142-5, 191.

11.Rhodes MC, Hebert CD, Herbert RA, Morinello EJ, Roycroft JH, Travlos GS, Abdo KM. Absence of toxic effects in F344/N rats and B6C3F1 mice following subchronic administration of chromium picolinate monohydrate. Food Chem Toxicol. 2005 Jan;43(1):21-9.

12.Ryan GJ, Wanko NS, Redman AR, Cook CB. Chromium as adjunctive treatment for type 2 diabetes. Ann Pharmacother. 2003 Jun;37(6):876-85.

13.Stearns DM, Belbruno JJ, Wetterhahn KE. A prediction of chromium(III) accumulation in humans from chromium dietary supplements. FASEB J. 1995 Dec;9(15):1650-7.

14.Trent LK, Thieding-Cancel D. Effects of chromium picolinate on body composition. J Sports Med Phys Fitness. 1995 Dec;35(4):273-80.

15.Walker LS, Bemben MG, Bemben DA, Knehans AW.Chromium picolinate effects on body composition and muscular performance in wrestlers. Med Sci Sports Exerc. 1998 Dec;30(12):1730-7.

16.Volpe SL, Huang HW, Larpadisorn K, Lesser II. Effect of chromium supplementation and exercise on body composition, resting metabolic rate and selected biochemical parameters in moderately obese women following an exercise program. J Am Coll Nutr. 2001 Aug;20(4):293-306.

EDITOR'S NOTE: This monograph can be found in The Health Professional's Guide to Dietary Supplements (Lippincott, Williams & Wilkins) by Shawn M. Talbott, PhD and Kerry Hughes, MS.

Fenugreek

Overview

Fenugreek is a popular spice in Indian cuisine and has a long use in both Ayervedic and Chinese traditional medicine, for uses including inducing lactation, inducing labor, aiding in digestion, and as a general health and wellness tonic (Basch et al., 2003; Gabay, 2002). Both animal and human clinical studies are finding that fenugreek shows promising therapeutic activity as a hypoglycemic and hypocholesterolaemic agent. The unique dietary fibers along with the high saponin content, and possibly an amino acid (4-Hydroxyisoleucine) in fenugreek is thought to be responsible for its activities (Madar, 2002; Sauvaire et al., 1998).

Comments

Vajifdar et al. (2000) included fenugreek dietary fiber in a dietary fiber mixture in a study which had favorable results on lowering LDL cholesterol, apolipoproteine A-1, body mass index and waist circumference. As the mechanisms of action of dietary fiber are assumed to be similar, this study shows promise for the use of fenugreek fiber for being helpful in ischemic heart disease. Likewise, fenugreek was found beneficial in the diabetic diet when combined with millet and legumes in another clinical study, and a combination of other herbs (Pathak et al., 2000; Bhardqaj et al., 1994).

Scientific Support

Type I & II Diabetes

Madar et al. (2002) tested the dietary effect of fenugreek in type II diabetics (non-insulin dependent) following the meal tolerance test (MTT). Powdered fenugreek (15 g) was added to the diets of type II diabetics, and found to significantly reduce the postprandial glucose levels, and non-significantly lower the plasma insulin levels as well. There was no effect on the blood lipid levels after 3 hours following the MTT.

Gupta et al. (2001) performed a double-blind, randomized, placebo-controlled study to determine the effect of fenugreek on glycemic control and insulin resistance in type II diabetics. The participants were given either fenugreek extract (hydroalcoholic; 1 g daily) or placebo for two months. Serum triglycerides were found to be reduced in the treatment group, as well as insulin control a a decrease in insulin resistance.

Sharma et al. (1990) tested the effect of fenugreek seeds on type I diabetic’s blood glucose levels and serum lipid profiles in a placebo-controlled clinical study. Fenugreek seed was administered in the treatment group diet (100 g daily), whereas isocaloric diets without fenugreek served as the control, and the diets were followed for 10 days. A 54% reduction in 24-hour urinary glucose excretion, along with significantly reduced serum total cholesterol, LDL, and VLDL cholesterol and triglycerides was found in the treatment group. The HDL levels remained unchanged between groups. The authors noted that fenugreek appeared useful in the diets of diabetics.

Hypocholesterolemic Effect

Sowmya and Rajyalakshmi (1999) tested the effect of dietary germinated fenugreek seed powder on blood lipid levels in hypocholesterolemic adults. Twenty participants were divided into two groups and asked to add the fenugreek powder to their meals for one month, the groups differed in the amount of fenugreek in the packet: either 12.5 g or 18 g daily. Both treatment levels resulted in a hypocholesterolemic effect, but the 18 g dosage resulted in significant reductions in total and LDL cholesterol levels. There were no changes found between the groups in HDL, VLDL and triglyceride levels. The authors claimed that the germination of the seeds was able to increase the solubility of the fiber content of fenugreek.

Safety / Dosage

Fenugreek seed powder has been found to be beneficial in the typical dosages of between 15-20 (and up) grams daily for reducing serum cholesterol levels and improving blood sugar control in diabetics. Fenugreek is considered quite safe, even at the higher doses needed for therapeutic use (Muralidhara et al., 1999). As is the case with other botanicals with high coumarin contents, there is concern with the potential adverse reaction of increasing bleeding, and an interaction with other blood-thinning drugs (Abebe, 2002).

References

1.Abebe W. Herbal medication: potential for adverse interactions with analgesic drugs. J Clin Pharm Ther. 2002 Dec;27(6):391-401.

2.Basch E, Ulbricht C, Kuo G, Szapary P, Smith M. Therapeutic applications of fenugreek. Altern Med Rev. 2003 Feb;8(1):20-7.

3.Bhardwaj PK, Dasgupta DJ, Prashar BS, Kaushal SS. Control of hyperglycaemia and hyperlipidaemia by plant product. J Assoc Physicians India. 1994 Jan;42(1):33-5.

4.Gabay MP. Galactogogues: medications that induce lactation. J Hum Lact. 2002 Aug;18(3):274-9.

5.Gupta A, Gupta R, Lal B. Effect of Trigonella foenum-graecum (fenugreek) seeds on glycaemic control and insulin resistance in type 2 diabetes mellitus: a double blind placebo controlled study. J Assoc Physicians India. 2001 Nov;49:1057-61.

6.Hibasami H, Moteki H, Ishikawa K, Katsuzaki H, Imai K, Yoshioka K, Ishii Y, Komiya T. Protodioscin isolated from fenugreek (Trigonella foenumgraecum L.) induces cell death and morphological change indicative of apoptosis in leukemic cell line H-60, but not in gastric cancer cell line KATO III. Int J Mol Med. 2003 Jan;11(1):23-6.

7.Madar Z, Abel R, Samish S, Arad J. Glucose-lowering effect of fenugreek in non-insulin dependent diabetics. Eur J Clin Nutr. 1988 Jan;42(1):51-4.

8.Madar Z, Stark AH.New legume sources as therapeutic agents. Br J Nutr. 2002 Dec;88 Suppl 3:S287-92.

9.Muralidhara, Narasimhamurthy K, Viswanatha S, Ramesh BS. Acute and subchronic toxicity assessment of debitterized fenugreek powder in the mouse and rat. Food Chem Toxicol. 1999 Aug;37(8):831-8.

10.Pathak P, Srivastava S, Grover S. Development of food products based on millets, legumes and fenugreek seeds and their suitability in the diabetic diet. Int J Food Sci Nutr. 2000 Sep;51(5):409-14.

11.Sauvaire Y, Petit P, Broca C, Manteghetti M, Baissac Y, Fernandez-Alvarez J, Gross R, Roye M, Leconte A, Gomis R, Ribes G. 4-Hydroxyisoleucine: a novel amino acid potentiator of insulin secretion. Diabetes. 1998 Feb;47(2):206-10.

12.Sharma RD, Raghuram TC, Rao NS. Effect of fenugreek seeds on blood glucose and serum lipids in type I diabetes. Eur J Clin Nutr. 1990 Apr;44(4):301-6.

13.Sowmya P, Rajyalakshmi P. Hypocholesterolemic effect of germinated fenugreek seeds in human subjects. Plant Foods Hum Nutr. 1999;53(4):359-65.

14.Vajifdar BU, Goyal VS, Lokhandwala YY, Mhamunkar SR, Mahadik SP, Gawad AK, Halankar SA, Kulkarni HL. Is dietary fiber beneficial in chronic ischemic heart disease? J Assoc Physicians India. 2000 Sep;48(9):871-6.

EDITOR'S NOTE: This monograph can be found in The Health Professional's Guide to Dietary Supplements (Lippincott, Williams & Wilkins) by Shawn M. Talbott, PhD and Kerry Hughes, MS