Review ArticlePractice

Complementary and alternative medicine for the treatment of type 2 diabetes

Richard Nahas and Matthew Moher
Canadian Family Physician June 2009, 55 (6) 591-596;

ABSTRACT

OBJECTIVE To review clinical evidence supporting complementary and alternative medicine interventions for improving glycemic control in type 2 diabetes mellitus.

QUALITY OF EVIDENCE MEDLINE and EMBASE were searched from January 1966 to August 2008 using the term type 2 diabetes in combination with each of the following terms for specific therapies selected by the authors: cinnamon, fenugreek, gymnema, green tea, fibre, momordica, chromium, and vanadium. Only human clinical trials were selected for review.

MAIN MESSAGE Chromium reduced glycosylated hemoglobin (HbA1c) and fasting blood glucose (FBG) levels in a large meta-analysis. Gymnema sylvestre reduced HbA1c levels in 2 small open-label trials. Cinnamon improved FBG but its effects on HbA1c are unknown. Bitter melon had no effect in 2 small trials. Fibre had no consistent effect on HbA1c or FBG in 12 small trials. Green tea reduced FBG levels in 1 of 3 small trials. Fenugreek reduced FBG in 1 of 3 small trials. Vanadium reduced FBG in small, uncontrolled trials. There were no trials evaluating microvascular or macrovascular complications or other clinical end points.

CONCLUSION Chromium, and possibly gymnema, appears to improve glycemic control. Fibre, green tea, and fenugreek have other benefits but there is little evidence that they substantially improve glycemic control. Further research on bitter melon and cinnamon is warranted. There is no complementary and alternative medicine research addressing microvascular or macrovascular clinical outcomes.

Type 2 diabetes mellitus (DM) is one of the most prevalent and fastest growing diseases in Canada, responsible for expenditures of 9 billion dollars per year.1 Family physicians play a central role in the management of diabetes. Although many drugs improve glycemic control, they do not necessarily provide real-world benefits. In the recent ACCORD (Action to Control Cardiovascular Risk in Diabetes)2 and ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation)3 trials, intensive glycemic control had minimal effect on clinical cardiovascular outcomes. In fact, in a recent meta-analysis, combination therapy with metformin and glyburide increased the risk of a composite end point of cardiovascular events and mortality (relative risk 1.43, 95% confidence interval [CI] 1.10 to 1.85).4 The use of thiazolidinediones has recently been called into question because they increase cardiovascular risk and fracture risk.5

More than one-third of Canadians are using complementary and alternative medicine (CAM) therapies,6 often without consulting or even informing their FPs. It is important for FPs to ask patients about their CAM use and provide evidence-based information about the safety and efficacy of commonly used CAM therapies.

Here we provide a brief review of the evidence supporting the use of several CAM therapies commonly used to treat type 2 DM.

Quality of evidence

MEDLINE and EMBASE were searched from January 1966 to August 2008. The search key words were type 2 diabetes in combination with each of cinnamon, fenugreek, gymnema, green tea, fibre, momordica, chromium, and vanadium. These interventions were selected by the authors based on literature reviews and clinical experience. Results were screened by one author to include clinical trials, systematic reviews, and meta-analyses. Only human clinical trials were selected for review.

Main findings

Relevant findings for each search term are briefly summarized in Table 1 and are detailed as follows:

View this table:
Table 1.

Summary of evidence supporting complementary and alternative medicine therapies for type 2 diabetes mellitus

Cinnamon

True cinnamon (Cinnamomum verum) is a small evergreen tree, the bark of which is a common culinary spice. Most cinnamon sold in the United States and Canada is actually derived from C aromaticum or C cassia, sometimes called “Chinese cinnamon” to distinguish it from C verum. Cinnamon has been used for thousands of years to treat diabetes and other conditions. The aqueous extract appears to activate the insulin receptor by multiple mechanisms, and also increases glycogen synthase activity.7–10

A recent meta-analysis identified 5 trials (N = 282) that evaluated C cassia at 1 to 6 g daily for 40 days to 4 months.11 One trial was not randomized, while another trial investigated adolescents with type 1 diabetes. The other 3 randomized controlled trials (RCTs) involved 196 patients. In one, 60 patients with poorly controlled diabetes were given 1, 3, or 6 g of C cassia for 40 days. Fasting blood glucose (FBG) levels decreased by 18% to 29%, but chromium-reduced glycosylated hemoglobin (HbA1c) levels were not investigated.12 In a second trial, 79 well-controlled diabetes patients received 3 g of C cassia daily for 4 months. More moderate reductions in FBG levels (average 10.3% vs 3.4% in placebo group, P = .046) were noted, but HbA1c levels were unchanged.13 In the third trial, 43 patients with diabetes with an average HbA1c measurement of 7.1% were treated with 1 g daily for 3 months. No change was reported in FBG or HbA1c levels.14

No significant adverse effects were reported in the reviewed trials. The only reported risk of cinnamon use is contact dermatitis from volatile oils. Safety in pregnancy has not been studied.

Overall, there is moderate evidence that cinnamon lowers blood glucose levels. Its effect on HbA1c appears negligible, but long-term studies are required to properly evaluate this outcome.

Chromium

Chromium is an essential trace element with many sites of action, including carbohydrate and lipid metabolism. Trivalent chromium is a constituent of a complex known as the “glucose tolerance factor,”15 and chromium deficiency causes reversible insulin resistance and diabetes.16–18

A meta-analysis identified 41 trials (N = 1198) that evaluated the effects of various chromium formulations at doses of 200 to 1000 μg daily for 2 to 26 weeks. Of these, 14 trials (n = 431) evaluated patients with type 2 DM and baseline HbA1c levels of 7.0% to 10.2%. Chromium picolinate and brewer’s yeast at doses of 200 to 1000 μg for 6 to 26 weeks reduced HbA1c levels by an average of 0.6% (95% CI −0.9% to −0.2%) and FBG levels by an average of 1 mmol/L (95% CI −1.4 to −0.5).19 These findings are limited by the fact that more than half the studies included were of poor quality and used different formulations and doses of chromium in populations that might have had very different amounts of chromium in their diet. No significant adverse effects were reported in any of the reviewed trials.

The meta-analysis included 2 RCTs that evaluated combination therapy using 600 μg chromium picolinate and 2 mg biotin. Biotin is a B vitamin that has enhanced chromium absorption in animal studies. One 3-month trial in 447 patients with diabetes (mean baseline HbA1c level 8.6%) noted an HbA1c level reduction of 0.54% (P = .03) overall, and an impressive 1.76% reduction among patients with baseline HbA1c levels above 10% (P = .0001).20 In the second trial, 36 patients with diabetes were treated for 1 month; no reduction in FBG was seen.21

There is strong evidence that 200 to 1000 μg of chromium picolinate daily improves glycemic control. Based on its safety and potential cost-effectiveness, a definitive clinical trial is urgently needed. Biotin might enhance its effects, but this combination requires further study.

Vanadium

Vanadium is a poorly understood trace element that is ubiquitous in nature and believed to have many functions in human physiology. In vitro and animal studies have demonstrated its insulinomimetic effects mediated by inhibition of phosphotyrosine phosphatase enzymes that affect the insulin receptor.22–24

A recent meta-analysis identified 5 uncontrolled trials (N = 48) in which 50 to 300 mg of vanadium was administered for 3 to 6 weeks.25 Vanadyl sulfate was used in 4 trials and sodium metavanadate was used in 1 trial. All 5 trials reported reductions in FBG levels, but these were of short duration; none of the trials included controls. Commonly reported side effects included gastrointestinal upset, bloating, and nausea.

There is insufficient evidence to support the use of vanadium in the treatment of type 2 DM.

Fibre

Dietary fibre is recognized as an important part of a healthy diet. Soluble and insoluble fibre have positive effects on cardiovascular risk factors,26 intestinal disorders,27 and certain cancers.28–30 Cohort studies suggest that consumption of cereal fibre and whole grains is inversely related to type 2 DM incidence.31

We identified 12 small RCTs (N = 345) that evaluated the effect of fibre in diabetes patients.32–43 Many different kinds of fibre were used, including wheat, guar, beet, soy, corn, agar, glucomannan, psyllium, and mixtures. Daily doses of 2 to 50 g were administered for 3 to 20 weeks. In 3 trials of 12 to 20 weeks’ duration, only 1 found an improvement in HbA1c levels: in this trial of 76 patients with well-controlled diabetes, a non-significant decrease from 6.6% to 6.1% was seen in those who consumed agar containing 4.5 g fibre daily for 12 weeks. Six of the 12 RCTs reported reductions in FBG; the other 6 RCTs reported no change in this outcome. Most of the studies also reported improvements in other risk factors, particularly those related to cholesterol levels. Some trials reported gastrointestinal side effects, including bloating, diarrhea, and abdominal pain.44

There is little evidence that dietary fibre improves glycemic control. Existing trials are limited by the heterogeneity of fibre formulations and the variation in doses and duration of treatment. Evidence of a short-term hypoglycemic effect in diabetes patients is conflicting. Nonetheless, fibre can be recommended based on its salutary effect on other cardiovascular risk factors.

Green tea

Green and black tea both originate from the leaves of the Camellia sinensis plant. Green tea is heated to inactivate the enzymes that would otherwise oxidize the freshly collected leaves. The numerous health benefits of tea consumption are attributed to polyphenol catechins, particularly epigallocatechin gallate.45,46 These compounds have improved insulin sensitivity and reduced β-cell damage in animal and in vitro studies.47–53 Although caffeine initially impairs glucose metabolism, long-term exposure stimulates lipolysis, increases basal energy expenditure, and mobilizes muscle glycogen.54,55 Prospective and retrospective population studies suggest that green tea consumption reduces the risk of type 2 DM by up to 48%.56,57 Surprisingly, only 1 small RCT (N = 49) has evaluated green tea in the context of diabetes. In this study, patients with baseline HbA1c levels of 6.5% to 9.1% were randomized to receive either an extract containing green tea catechins and black tea theaflavins or placebo for 3 months. No improvements in HbA1c levels were seen and FBG values were not measured.58 Side effects included a generalized rash in 1 patient and diaphoresis in 1 patient.

Three open-label trials (N = 141) of 1 to 2 months’ duration reported no changes in HbA1c values.59–61 Investigators in one trial administered 1.5 L of oolong (partly oxidized) tea to 20 patients for 4 weeks and reported a 30% decrease in FBG levels (P < .001).44

There is little evidence to support the use of green tea for glycemic control. Epidemiologic data suggest large potential benefits, but further research is warranted. Green tea consumption should still be recommended for its other potential health benefits.

Bitter melon

Bitter melon (Momordica charantia) is a tropical vine that produces fruit that is used to treat diabetes in many traditional cultures, including Indian Ayurvedic medicine. Several of its active ingredients, including charantin, vicine, and polypeptide-p,62–64 are believed to stimulate insulin secretion and alter hepatic glucose metabolism.65–67

Two RCTs have evaluated the effects of bitter melon in patients with type 2 DM. In one RCT, 40 patients with baseline HbA1c values of 7% to 9% were given either 3 g of fruit and seed extract or placebo. After 3 months, there was no change in HbA1c or FBG values.68 The other trial, in which 51 patients consumed either 6 g of fruit and seed extract or placebo for 1 month, also reported no effect on HbA1c or FBG values.69 No side effects were reported in either trial.

There is no evidence to support the use of bitter melon. It should be noted that stimulating insulin release is probably less desirable than improving insulin sensitivity. Bitter melon’s widespread traditional use merits further study, particularly in patients originating from cultures with a long history of traditional use.

Fenugreek

Fenugreek (Trigonella foenum-graecum) has been cultivated and used medicinally and ceremonially for thousands of years in Asian and Mediterranean cultures. Its leaves and seeds are used to treat diabetes in Ayurvedic and other traditional medical systems. The most studied active ingredient is 4-hydroxyisoleucine, which increases pancreatic insulin secretion and inhibits sucrose α-d-glucosidase and α-amylase.70–72 Additionally, fenugreek seeds are used to lower cholesterol, as sapogenins in the seeds increase biliary secretion73–80; they are also a good source of fibre.

Three small short-term RCTs (N = 50) have evaluated fenugreek in patients with type 2 DM. In one trial, 25 patients consumed 1 g of seed extract or placebo for 2 months with no change in FBG levels.81 In a small crossover study, 10 patients added 25 g of defatted seed powder to 1 meal or ate the meal without the powder for 15 days. Several measures of glucose metabolism were all unchanged.82 A third trial, which used a higher dose (100 g) of defatted seed powder in 15 patients for 10 days, did report improvements in FBG values.83 None of the trials investigated HbA1c levels. No adverse effects were reported.

There is very limited evidence to support the use of fenugreek in diabetes management. High doses of seed powder might be effective but require further study and are likely impractical for most patients. Its widespread traditional use and its reported lipid-lowering benefits warrant further study.

Gymnema

Gymnema sylvestre is also known as gurmar (sugar destroyer) in Hindi. The leaves of this plant are used in Ayurvedic medicine to treat diabetes, cholesterol, and obesity.84 Gymnemic acid, a mixture of many different saponins, is believed to be the active fraction, although a clear mechanism of action is yet to be been determined.85

Two small open-label trials have yielded promising results. In the first trial, 22 patients with type 2 DM were given either 200 mg of an ethanolic extract daily or their usual treatment for 18 to 20 months. Significant improvements in FBG and HbA1c levels (P < .001 for both) were noted in the test group.86 The other trial was uncontrolled, but reported that 3 months of treatment with 800 mg daily of a similar extract reduced FBG levels by 11% and HbA1c levels by 0.6% in a mixed population of 65 patients with type 1 and type 2 diabetes.87 No adverse effects were reported in either trial.

Preliminary evidence of any benefit is probably insufficient to support the widespread use of G sylvestre for diabetes management at this time. The significant improvements in HbA1c levels definitely warrant further study as well as judicious use in selected patients.

Conclusion

Changes in HbA1c values are most often used to evaluate hypoglycemic effects. It is important to consider that the life span of a red blood cell is 120 days. Therefore, studies investigating diabetes management should involve HbA1c measurements and should be of at least 4 months’ duration. Most of these trials were of insufficient duration to evaluate this outcome. None of the research examined has addressed the potential effect of CAM interventions on cardiovascular outcomes. This is important because better glycemic control might not always lead to real-world clinical benefits. It is also important because some interventions can improve other cardiovascular risk factors.

Overall, there is a paucity of research evaluating CAM therapies that are commonly used to treat type 2 DM. This should be a high priority for CAM researchers and funding agencies.

Notes

EDITOR’S KEY POINTS

  • Chromium (200 to 1000 μg per day) is the only complementary and alternative medicine intervention with level 1 evidence to support its use in diabetes management, but a large-scale clinical trial is needed to confirm these findings.

  • Small studies indicate that Gymnema sylvestre improves HbA1c levels. Larger studies are required to confirm these promising findings.

  • Cinnamon probably lowers blood glucose levels, but its effects on HbA1c levels are unknown.

  • Bitter melon has a long history of traditional use, but preliminary evidence suggests its benefits might be limited.

  • Vanadium is poorly understood, has potential adverse side effects, and should probably be avoided.

  • Green tea, fenugreek, and fibre can be recommended on account of their other health benefits, but evidence that they improve glycemic control is limited and conflicting.

POINTS DE REPÈRE DU RÉDACTEUR

  • La seule substance en médecine complémentaire et alternative dont l’usage dans le traitement du diabète s’appuie sur des preuves de niveau 1 est le chrome (200 à 1000 μg/d), mais il faudra un essai clinique à grande échelle pour confirmer ces observations.

  • Certaines petites études indiquent que le gymnema sylvestre améliore les niveaux de HbA1c. Ces résultats prometteurs devront être confirmés par de plus larges études.

  • La cannelle abaisse probablement le glucose sanguin, mais on ignore ses effets sur le HbA1c.

  • La margose est d’usage traditionnel depuis long-temps, mais des données préliminaires suggèrent que ses avantages pourraient être limités.

  • Les effets du vanadium sont mal connus; il pourrait avoir des effets indésirables et on devrait vraisem-blablement l’éviter.

  • Le thé vert, le fenugrec et les fibres peuvent être recommandés à cause de leurs autres effets bénéfiques sur la santé, mais les preuves qu’ils améliorent le contrôle de la glycémie sont limitées et contradictoires.

Footnotes

  • This article has been peer reviewed.

  • Cet article a fait l’objet d’une révision par des pairs.

  • Contributors

    Dr Nahas and Mr Moher contributed to the literature review, selection and review of studies, and preparation of the manuscript for publication.

  • Competing interests

    None declared

References

  1. 1.↵
    1. Health Canada
    It’s your health. Type 2 diabetesOttawa, ONHealth Canada2004Available from: www.hc-sc.gc.ca/hl-vs/iyh-vsv/diseases-maladies/diabete-eng.php. Accessed 2009 Apr 17.
  2. 2.↵
    1. Action to Control Cardiovascular Risk in Diabetes Study Group,
    2. Gerstein HC,
    3. Miller ME,
    4. Byington RP,
    5. Goff DC Jr.,
    6. Bigger JT,
    7. et al.
    Effects of intensive glucose lowering in type 2 diabetesN Engl J Med200835824254559. Epub 2008 Jun 6.
    OpenUrlCrossRefPubMed
  3. 3.↵
    1. ADVANCE Collaborative Group,
    2. Patel A,
    3. MacMahon S,
    4. Chalmers J,
    5. Neal B,
    6. Billot L,
    7. et al.
    Intensive blood glucose control and vascular outcomes in patients with type 2 diabetesN Engl J Med200835824256072. Epub 2008 Jun 6.
    OpenUrlCrossRefPubMed
  4. 4.↵
    1. Rao AD,
    2. Kuhadiya N,
    3. Reynolds K,
    4. Fonseca VA
    Is the combination of sulfonylureas and metformin associated with an increased cardiovascular disease or all-cause mortality? A meta-analysis of observational studiesDiabetes Care200831816728. Epub 2008 May 5.
    OpenUrlAbstract/FREE Full Text
  5. 5.↵
    1. Lipscombe LL
    Thiazolidinediones: do harms outweigh benefits?CMAJ20091801167. Epub 2008 Dec 10.
    OpenUrlFREE Full Text
  6. 6.↵
    McFarlandBBigelowDZaniBNewsomJKaplanMComplementary and alternative medicine use in Canada and the United StatesAm J Public Health2002921016168
    OpenUrlPubMed
  7. 7.↵
    Imparl-RadosevichJDeasSPolanskyMMBaedkeDAIngebritsenTSAndersonRARegulation of PTP-1 and insulin receptor kinase by fractions from cinnamon: implications for cinnamon regulation of insulin signalingHorm Res199850317782
    OpenUrlCrossRefPubMed
  8. 8.
    Jarvill-TaylorKJAndersonRAGravesDJA hydroxychalcone derived from cinnamon functions as a mimetic for insulin in 3T3-L1 adipocytesJ Am Coll Nutr200120432736
    OpenUrlCrossRefPubMed
  9. 9.
    QinBNagasakiMRenMBajottoGOshidaYSatoYCinnamon extract (traditional herb) potentiates in vivo insulin-regulated glucose utilization via enhancing insulin signaling in ratsDiabetes Res Clin Pract200362313948
    OpenUrlCrossRefPubMed
  10. 10.↵
    1. Cao H,
    2. Polansky MM,
    3. Anderson RA
    Cinnamon extract and polyphenols affect the expression of tristetraprolin, insulin receptor, and glucose transporter 4 in mouse 3T3-L1 adipocytesArch Biochem Biophys2007459221422. Epub 2007 Jan 25.
    OpenUrlCrossRefPubMed
  11. 11.↵
    1. Baker WL,
    2. Gutierrez-Williams G,
    3. White CM,
    4. Kluger J,
    5. Coleman CI
    Effect of cinnamon on glucose control and lipid parametersDiabetes Care2008311413. Epub 2007 Oct 1.
    OpenUrlAbstract/FREE Full Text
  12. 12.↵
    KhanASafdarMAli KhanMMKhattakKNAndersonRACinnamon improves glucose and lipids of people with type 2 diabetesDiabetes Care2003261232158
    OpenUrlAbstract/FREE Full Text
  13. 13.↵
    MangBWoltersMSchmittBKelbKLichtinghagenRStichtenothDOEffects of a cinnamon extract on plasma glucose, HbA, and serum lipids in diabetes mellitus type 2Eur J Clin Invest20063653404
    OpenUrlCrossRefPubMed
  14. 14.↵
    1. Blevins SM,
    2. Leyva MJ,
    3. Brown J,
    4. Wright J,
    5. Scofield RH,
    6. Aston CE
    Effect of cinnamon on glucose and lipid levels in non insulin-dependent type 2 diabetesDiabetes Care200730922367. Epub 2007 Jun 11.
    OpenUrlFREE Full Text
  15. 15.↵
    SchwarzKMertzWChromium (III) and the glucose tolerance factorArch Biochem Biophys1959852925
    OpenUrlCrossRefPubMed
  16. 16.↵
    JeejeebhoyKNChuRCMarlissEBGreenbergGRBruce-RobertsonAChromium deficiency, glucose intolerance, and neuropathy reversed by chromium supplementation, in a patient receiving long-term total parenteral nutritionAm J Clin Nutr19773045318
    OpenUrlAbstract/FREE Full Text
  17. 17.
    BrownROForloines-LynnSCrossREHeizerWDChromium deficiency after long-term total parenteral nutritionDig Dis Sci19863166614
    OpenUrlCrossRefPubMed
  18. 18.↵
    FreundHAtamianSFischerJEChromium deficiency during total parenteral nutritionJAMA197924154968
    OpenUrlCrossRefPubMed
  19. 19.↵
    1. Balk EM,
    2. Tatsioni A,
    3. Lichtenstein AH,
    4. Lau J,
    5. Pittas AG
    Effect of chromium supplementation on glucose metabolism and lipids: a systematic review of randomized controlled trialsDiabetes Care2007308215463. Epub 2007 May 22.
    OpenUrlAbstract/FREE Full Text
  20. 20.↵
    AlbarracinCAFuquaBCEvansJLGoldfineIDChromium picolinate and biotin combination improves glucose metabolism in treated, uncontrolled overweight to obese patients with type 2 diabetesDiabetes Metab Res Rev20082414151
    OpenUrlCrossRefPubMed
  21. 21.↵
    GeohasJDalyAJuturuVFinchMKomorowskiJRChromium picolinate and biotin combination reduces atherogenic index of plasma in patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized clinical trialAm J Med Sci2007333314553
    OpenUrlCrossRefPubMed
  22. 22.↵
    1. O’Connell BS
    Selected vitamins and minerals in the management of diabetesDiabetes Spectrum200114313348. Available from: http://spectrum.diabetesjournals.org/cgi/reprint/14/3/133.pdf. Accessed 2009 Apr 17.
    OpenUrlAbstract/FREE Full Text
  23. 23.
    VermaSCamMCMcNeillJHNutritional factors that can favorably influence the glucose/insulin system: vanadiumJ Am Coll Nutr1998171118
    OpenUrlPubMed
  24. 24.↵
    PandeySKAnand-SrivastavaMBSrivastavaAKVanadyl sulfate-stimulated glycogen synthesis is associated with activation of phosphatidylinositol 3-kinase and is independent of insulin receptor tyrosine phosphorylationBiochemistry19983719700614
    OpenUrlCrossRefPubMed
  25. 25.↵
    1. Smith DM,
    2. Pickering RM,
    3. Lewith GT
    A systematic review of vanadium oral supplements for glycaemic control in type 2 diabetes mellitusQJM200810153518. Epub 2008 Mar 4.
    OpenUrlAbstract/FREE Full Text
  26. 26.↵
    1. Galisteo M,
    2. Duarte J,
    3. Zarzuelo A
    Effects of dietary fibers on disturbances clustered in the metabolic syndromeJ Nutr Biochem20081927184. Epub 2007 Jul 6.
    OpenUrlCrossRefPubMed
  27. 27.↵
    MarlettJAMcBurneyMISlavinJLAmerican Dietetic AssociationPosition of the American Dietetic Association: health implications of dietary fiberJ Am Diet Assoc200210279931000
    OpenUrlCrossRefPubMed
  28. 28.↵
    CummingsJHBinghamSAHeatonKWEastwoodMAFecal weight, colon cancer risk and dietary intake of nonstarch polysaccharides (dietary fiber)Gastroenterology1992103617839
    OpenUrlPubMed
  29. 29.
    HoweGRBenitoECastelletoRCornéeJEstèveJGallagherRPDietary intake of fiber and decreased risk of cancers of the colon and rectum: evidence from the combined analysis of 13 case–control studiesJ Natl Cancer Inst19928424188796
    OpenUrlAbstract/FREE Full Text
  30. 30.↵
    1. Prentice RL
    Future possibilities in the prevention of breast cancer: fat and fiber and breast cancer researchBreast Cancer Res20002426876. Epub 2000 May 19.
    OpenUrlCrossRefPubMed
  31. 31.↵
    MurakamiKOkuboHSasakiSEffect of dietary factors on incidence of type 2 diabetes: a systematic review of cohort studiesJ Nutri Sci Vitaminol (Tokyo)2005514292310
    OpenUrl
  32. 32.↵
    BeattieVAEdwardsCAHoskerJPCullenDRWardJDReadNWDoes adding fibre to a low energy, high carbohydrate, low fat diet confer any benefit to the management of newly diagnosed overweight type II diabetics?Br Med J (Clin Res Ed)1988296663011479
    OpenUrlPubMed
  33. 33.
    VuksanVJenkinsDJSpadaforaPSievenpiperJLOwenRVidgenEKonjac-mannan (glucomannan) improves glycemia and other associated risk factors for coronary heart disease in type 2 diabetes. A randomized controlled metabolic trialDiabetes Care19992269139
    OpenUrlAbstract
  34. 34.
    Rodríguez-MoránMGuerrero-RomeroFLazcano-BurciagaGLipid- and glucose-lowering efficacy of Plantago Psyllium in type II diabetesJ Diabetes Complications19981252738
    OpenUrlCrossRefPubMed
  35. 35.
    MahalkoJRSandsteadHHJohnsonLKInmanLFMilneDBWarnerRCEffect of consuming fiber from corn bran, soy hulls, or apple powder on glucose tolerance and plasma lipids in type 2 diabetesAm J Clin Nutr19843912534
    OpenUrlAbstract/FREE Full Text
  36. 36.
    MaedaHYamamotoRHiraoKTochikuboOEffects of agar (kanten) diet on obese patients with impaired glucose tolerance and type 2 diabetesDiabetes Obes Metab200571406
    OpenUrlCrossRefPubMed
  37. 37.
    KarlanderSArmyrIEfendicSMetabolic effects and clinical value of beet fibre treatment in NIDDM patientsDiabetes Res Clin Pract19911126571
    OpenUrlPubMed
  38. 38.
    ChoSHKimTHLeeNHSonHSChoIJHaTYEffects of Cassia tora fibre supplement on serum lipids in Korean diabetic patientsJ Med Food2005833118
    OpenUrlCrossRefPubMed
  39. 39.
    JenkinsDJKendallCWAugustinLSMartiniMCAxelsenMFaulknerDEffect of wheat bran on glycemic control and risk factors for cardiovascular disease in type 2 diabetesDiabetes Care200225915228
    OpenUrlAbstract/FREE Full Text
  40. 40.
    KarlströmBVessbyBAspNGBobergMGustafssonIBLithellHEffects of an increased content of cereal fibre in the diet of type 2 (non-insulin-dependent) diabetic patientsDiabetologia19842642727
    OpenUrlPubMed
  41. 41.
    HollenbeckCBCoulstonAMReavenGMTo what extent does increased dietary fiber improve glucose and lipid metabolism in patients with noninsulin-dependent diabetes mellitus (NIDDM)?Am J Clin Nutr19864311624
    OpenUrlAbstract/FREE Full Text
  42. 42.
    LuZXWalkerKZMuirJGO’DeaKArabinoxylan fibre improves metabolic control in people with type II diabetesEur J Clin Nutr20045846218
    OpenUrlCrossRefPubMed
  43. 43.↵
    ChandaliaMGargALutjohannDvon BergmannKGrundySBrinkleyLJBeneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitusN Engl J Med20003421913928
    OpenUrlCrossRefPubMed
  44. 44.↵
    ChuangLMJouTSYangWSWuHPHuangSHTaiTYTherapeutic effect of guar gum in patients with non-insulin-dependent diabetes mellitusJ Formos Med Assoc1992911159
    OpenUrlPubMed
  45. 45.↵
    HigdonJVFreiBTea catechins and polyphenols: health effects, metabolism, and antioxidant functionsCrit Rev Food Sci Nutr200343189143
    OpenUrlCrossRefPubMed
  46. 46.↵
    1. Nagle DG,
    2. Ferreira D,
    3. Zhou YD
    Epigallocatechin-3-gallate (EGCG): chemical and biomedical perspectivesPhytochemistry20066717184955. Epub 2006 Jul 31.
    OpenUrlCrossRefPubMed
  47. 47.↵
    AndersonRAPolanskyMMTea enhances insulin activityJ Agric Food Chem2002502471826
    OpenUrlCrossRefPubMed
  48. 48.
    GomesAVedasiromoniJRDasMSharmaRMGangulyDKAntihyperglycemic effect of black tea (Camellia sinensis) in ratJ Ethnopharmacol19954532236
    OpenUrlPubMed
  49. 49.
    BroadhurstCLPolanskyMMAndersonRAInsulin-like biological activity of culinary and medicinal plant aqueous extracts in vitroJ Agric Food Chem200048384952
    OpenUrlCrossRefPubMed
  50. 50.
    1. Wu LY,
    2. Juan CC,
    3. Hwang LS,
    4. Hsu YP,
    5. Ho PH,
    6. Ho LT
    Green tea supplementation ameliorates insulin resistance and increases glucose transporter IV content in a fructose-fed rat modelEur J Nutr200443211624. Epub 2004 Jan 6.
    OpenUrlCrossRefPubMed
  51. 51.
    1. Waltner-Law ME,
    2. Wang XL,
    3. Law BK,
    4. Hall RK,
    5. Nawano M,
    6. Granner DK
    Epigallocatechin gallate, a constituent of green tea, represses hepatic glucose productionJ Biol Chem2002277383493340. Epub 2002 Jul 12.
    OpenUrlAbstract/FREE Full Text
  52. 52.
    SabuMCSmithaKKuttanRAnti-diabetic activity of green tea polyphenols and their role in reducing oxidative stress in experimental diabetesJ Ethnopharmacol2002831–210916
    OpenUrlCrossRefPubMed
  53. 53.↵
    WolframSRaederstorffDPrellerMWangYTeixeiraSRRieggerCEpigallocatechin gallate supplementation alleviates diabetes in rodentsJ Nutr20061361025128
    OpenUrlAbstract/FREE Full Text
  54. 54.↵
    LaneJDBarkauskasCESurwitRSFeinglosMNCaffeine impairs glucose metabolism in type 2 diabetesDiabetes Care200427820478
    OpenUrlFREE Full Text
  55. 55.↵
    RobinsonLESavaniSBattramDSMcLarenDHSathasivamPGrahamTECaffeine ingestion before an oral glucose tolerance test impairs blood glucose management in men with type 2 diabetesJ Nutr200413410252833
    OpenUrlAbstract/FREE Full Text
  56. 56.↵
    IsoHDateCWakaiKFukuiMTamakoshiAJACC Study GroupThe relationship between green tea and total caffeine intake and risk for self-reported type 2 diabetes among Japanese adultsAnn Intern Med2006144855462
    OpenUrlCrossRefPubMed
  57. 57.↵
    1. Polychronopoulos E,
    2. Zeimbekis A,
    3. Kastorini CM,
    4. Papairakleous N,
    5. Vlachou I,
    6. Bountziouka V,
    7. et al.
    Effects of black and green tea consumption on blood glucose levels in non-obese elderly men and women from Mediterranean Islands (MEDIS epidemiological study)Eur J Nutr2008471106. Epub 2008 Jan 18.
    OpenUrlCrossRefPubMed
  58. 58.↵
    MackenzieTLearyLBrooksWBThe effect of an extract of green and black tea on glucose control in adults with type 2 diabetes mellitus: double-blind randomized studyMetabolism2007561013404
    OpenUrlCrossRefPubMed
  59. 59.↵
    1. Ryu OH,
    2. Lee J,
    3. Lee KW,
    4. Kim HY,
    5. Seo JA,
    6. Kim SG,
    7. et al.
    Effects of green tea consumption on inflammation, insulin resistance and pulse wave velocity in type 2 diabetes patientsDiabetes Res Clin Pract20067133568. Epub 2005 Sep 19.
    OpenUrlCrossRefPubMed
  60. 60.
    FukinoYShimboMAokiNOkuboTIsoHRandomized controlled trial for an effect of green tea consumption on insulin resistance and inflammation markersJ Nutr Sci Vitaminol (Tokyo)200551533542
    OpenUrlCrossRefPubMed
  61. 61.↵
    HosodaKWangMFLiaoMLChuangCKIhaMClevidenceBAntihyperglycemic effect of oolong tea in type 2 diabetesDiabetes Care200326617148
    OpenUrlAbstract/FREE Full Text
  62. 62.↵
    1. Torres WD
    Momordica charantia Linn. (Family: Cucurbitaceae)—chemistry and pharmacology [review]Las Vegas, NVAmerican Academy of Anti-Aging Medicine2004Available from: www1.charanteausa.com/bittermelonstudies/2006/07/17/momordica-charantia-linn-family-cucurbitaceae. Accessed 2009 Apr 17.
  63. 63.
    BaschEGabardiSUlbrichtCBitter melon (Momordica charantia): a review of efficacy and safetyAm J Health Syst Pharm20036043569
    OpenUrlAbstract/FREE Full Text
  64. 64.↵
    BaldwaVSBhandariCMPangariaAGoyalRKClinical trial in patients with diabetes mellitus of an insulin-like compound obtained from plant sourceUps J Med Sci1977823941
    OpenUrlPubMed
  65. 65.↵
    WelihindaJKarunanayakeEHSheriffMHJayasingheKSEffect of Momordica charantia on the glucose tolerance in maturity onset diabetesJ Ethnopharmacol198617327782
    OpenUrlCrossRefPubMed
  66. 66.
    1. Shibib BA,
    2. Khan LA,
    3. Rahman R
    Hypoglycaemic activity of Coccinia indica and Momordica charantia in diabetic rats: depression of the hepatic gluconeogenic enzymes glucose-6-phosphatase and fructose-1,6-bisphos-phatase and elevation of both liver and red-cell shunt enzyme glucose-6-phosphate dehydrogenaseBiochem J1993292(Pt 1)26770
    OpenUrlAbstract/FREE Full Text
  67. 67.↵
    YehGYEisenbergDMKaptchukTJPhillipsRSSystematic review of herbs and dietary supplements for glycemic control in diabetesDiabetes Care2003264127794
    OpenUrlAbstract/FREE Full Text
  68. 68.↵
    1. Dans AM,
    2. Villarruz MV,
    3. Jimeno CA,
    4. Javelosa MA,
    5. Chua J,
    6. Bautista R,
    7. et al.
    The effect of Momordica charantia capsule preparation on glycemic control in type 2 diabetes mellitus needs further studiesJ Clin Epidemiol20076065549. Epub 2006 Nov 13.
    OpenUrlCrossRefPubMed
  69. 69.↵
    JohnAJCherianRSubhashHSCherianAMEvaluation of the efficacy of bitter gourd (momordica charantia) as an oral hypoglycemic agent—a randomized controlled clinical trialIndian J Physiol Pharmacol20034733635
    OpenUrlPubMed
  70. 70.↵
    SauvaireYPetitPBrocaCManteghettiMBaissacYFernandez-AlvarezJ4-Hydroxyisoleucine: a novel amino acid potentiator of insulin secretionDiabetes199847220610
    OpenUrlAbstract/FREE Full Text
  71. 71.
    AjabnoorMATilmisanyAKEffect of Trigonella foenum graceum on blood glucose levels in normal and alloxan-diabetic miceJ Ethnopharmacol1988221459
    OpenUrlPubMed
  72. 72.↵
    AminRAbdul-GhaniASSuleimanMSEffect of Trigonella feonum graecum on intestinal absorption. Proc. Of the 47th Annual Meeting of the American Diabetes Assocation (Indianapolis U.S.A.)Diabetes198736Suppl 1211a
    OpenUrl
  73. 73.↵
    StarkAMadarZThe effect of an ethanol extract derived from fenugreek (Trigonella foenum-graecum) on bile acid absorption and cholesterol levels in ratsBr J Nutr199369127787
    OpenUrlCrossRefPubMed
  74. 74.
    PetitPSauvaireYPonsinGManteghettiMFaveARibesGEffects of a fenugreek seed extract on feeding behaviour in the rat: metabolic-endocrine correlatesPharmacol Biochem Behav199345236974
    OpenUrlPubMed
  75. 75.
    Al-HaboriMAl-AghbariAMAl-MamaryMEffects of fenugreek seeds and its extracts on plasma lipid profile: a study on rabbitsPhytother Res19981285725
    OpenUrl
  76. 76.
    Al-HaboriMRamanAAntidiabetic and hypocholesterolaemic effects of fenugreekPhytother Res199812423342
    OpenUrlCrossRef
  77. 77.
    ValetteGSauvaireYBaccouJCRibesGHypocholesterolaemic effect of fenugreek seeds in dogsAtherosclerosis198450110511
    OpenUrlCrossRefPubMed
  78. 78.
    SauvaireYRibesGBaccouJCLoubatieères-MarianiMMImplication of steroid saponins and sapogenins in the hypocholesterolemic effect of fenugreekLipids19912631917
    OpenUrlCrossRefPubMed
  79. 79.
    VarshneyIPSharmaSCSaponins and sapogenins: part XXXII. Studies on Trigonella foenum-graecum Linn. seedsJ Indian Chem Soc1966435647
    OpenUrl
  80. 80.↵
    SidhuGSOakenfullDGA mechanism for the hypocholesterolaemic activity of saponinsBr J Nutr19865536439
    OpenUrlCrossRefPubMed
  81. 81.↵
    GuptaAGuptaRLalBEffect of Trigonella foenum-graecum (fenugreek) seeds on glycaemic control and insulin resistance in type 2 diabetes mellitus: a double blind placebo controlled studyJ Assoc Physicians India200149105761
    OpenUrlPubMed
  82. 82.↵
    RaghuramTCSharmaRDSivakumarBSahayBKEffect of fenugreek seeds on intravenous glucose disposition in non-insulin dependent diabetic patientsPhytother Res199482836
    OpenUrlCrossRef
  83. 83.↵
    SharmaRDRaghuramTCHypoglycaemic effect of fenugreek seeds in non-insulin dependent diabetics subjectsNutr Res19901077319
    OpenUrlCrossRef
  84. 84.↵
    1. Bone K
    Gymnema: a key herb in the management of diabetesPort Townsend, WATownsend Letter for Doctors and Patients2002Available from: www.townsendletter.com/Dec2002/phytotherapy1202.htm. Accessed 2009 Apr 17.
  85. 85.↵
    PorchezhianEDobriyalRMAn overview on the advances of Gymnema sylvestre: chemistry, pharmacology and patentsPharmazie2003581512
    OpenUrlPubMed
  86. 86.↵
    BaskaranKKizar AhamathBRadha ShanmugasundaramKShanmugasundaramERAntidiabetic effect of a leaf extract from Gymnema sylvestre in non-insulin-dependent diabetes mellitus patientsJ Ethnopharmacol1990303295305
    OpenUrlCrossRefPubMed
  87. 87.↵
    1. Joffe D
    Gymnema sylvestre lowers HbA1cDiabetes Control Newsl2001761Available from: www.diabetesincontrol.com/studies/gymnema1_2.shtml. Accessed 2009 Apr 17.
    OpenUrl
Back to top

In this issue

Print
Download PDF
Article Alerts
Email Article
Citation Tools
Respond to this article
Complementary and alternative medicine for the treatment of type 2 diabetes
Richard Nahas, Matthew Moher
Canadian Family Physician Jun 2009, 55 (6) 591-596;
Reddit logo Twitter logo Facebook logo Mendeley logo

Jump to section