Garlic for peripheral arterial occlusive disease

  • Review
  • Intervention

Authors


Abstract

Background

Commercially available preparations of garlic have been reported to have beneficial effects on some of the risk factors associated with atherosclerosis.

Objectives

To assess the effects of garlic (both dried and non-powdered preparations) for the treatment of peripheral arterial occlusive disease.

Search methods

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched January 2013) and CENTRAL (2012, Issue 12).

Selection criteria

Randomised trials of garlic therapy in patients with lower limb atherosclerosis were included. The main outcomes were objective measures of progression of underlying atherosclerosis (e.g. ankle pressure measurements, treadmill testing) and subjective measures (e.g. symptom progression).

Data collection and analysis

Two review authors (RJ and JK) independently extracted data and assessed trial quality. One author (RJ) contacted investigators to obtain information needed for the review that could not be found in published reports.

Main results

One eligible trial with 78 participants was found. Both men and women (aged 40 to 75) were included. The follow-up period was short, 12 weeks only.

After twelve weeks of treatment, pain-free walking distance increased from 161 to 207 metres in the group receiving garlic and from 172 to 203 metres in the placebo group. This was not a statistically significant difference. There was no difference in change of systolic or diastolic blood pressure, heart rate, ankle and brachial pressures. No severe side effects were observed and nine patients taking garlic (28%) and four patients taking placebo (12%) complained of a noticeable garlic smell.

Three trials were excluded from the review because they did not include any clinical measurements.

Authors' conclusions

One small trial of short duration found no statistically significant effect of garlic on walking distance.

Résumé scientifique

L'ail pour lartériopathie oblitérante des membres inferieurs

Contexte

Les préparations d'ail commercialisées ont été rapportées pour avoir des effets bénéfiques sur certains des facteurs de risque associés à l'athérosclérose.

Objectifs

Évaluer les effets de l'ail (sous forme de préparations en poudre et solides) pour le traitement de lartériopathie oblitérante des membres inferieurs.

Stratégie de recherche documentaire

Pour cette mise à jour, le registre du groupe Cochrane sur les maladies vasculaires périphériques a effectué des recherches dans recherche dans le registre spécialisé (dernière recherche en janvier 2013) et CENTRAL (2012, numéro 12).

Critères de sélection

Les essais randomisés du traitement de l'ail chez les patients atteints d'athérosclérose des membres inférieurs ont été inclus. Les critères de jugement principaux étaient des mesures objectives de la progression de l'athérosclérose sous jacente (par ex. les mesures de la pression de la cheville, des tests réalisés sur tapis roulant) et des mesures subjectives (par ex. évolution des symptômes).

Recueil et analyse des données

Deux auteurs de la revue (RJ et JK) ont indépendamment extrait les données et évalué la qualité des essais. Un auteur (RJ) a contacté les investigateurs afin d'obtenir des informations nécessaires pour la revue qui n'ont pas pu être trouvée dans les rapports publiés.

Résultats principaux

Un essai éligible de 78 participants a été trouvée. Des hommes et femmes (âgés de 40 à 75 ans) ont été inclus. La période de suivi était de courte durée, 12 semaines uniquement.

Après douze semaines de traitement, la distance de marche sans douleur augmentait de 161 à 207 mètres dans le groupe recevant de l'ail et de 172 à 203 mètres dans le groupe sous placebo. Cette différence n'était pas statistiquement significative. Il n'y avait aucune différence en termes de changement de la pression artérielle systolique ou diastolique, le rythme cardiaque, et de la cheville pressions tibio-brachiales. Aucun effet secondaire grave n'a été observé et neuf patients prenant de l'ail (28 %) et quatre patients prenant un placebo (12 %) se sont plaints d'une forte odeur d'ail.

Trois essais ont été exclus de la revue car ils ne comportaient pas de mesures cliniques objectives.

Conclusions des auteurs

Un essai de petite taille de courte durée n'a trouvé aucun effet statistiquement significatif de l'ail sur la distance de marche.

アブストラクト

末梢動脈閉塞性疾患に対するニンニク

背景

市販のニンニク製剤は、アテローム動脈硬化症と関連する危険因子の一部に有益な効果をもたらすことが報告されている。

目的

末梢動脈閉塞性疾患の治療に対するニンニク(乾燥製剤・非粉末製剤の両者)の効果を評価すること。

検索戦略

今回の更新では、 Cochrane Peripheral Vascular Diseases Groupの試験検索コーディネーターがSpecialised Register(最終検索時は2013年1月)とCENTRAL(2012年第12号)を検索した。

選択基準

下肢動脈硬化症の患者を対象としたニンニク療法ランダム化試験を選択した。基礎疾患としてのアテローム性動脈硬化症の進行の客観的指標(例えば、足関節血圧測定、トレッドミル試験)および主観的指標(症状の進行など)を主要アウトカムとした。

データ収集と分析

2名のレビュー著者(RJとJK)が独立してデータを抽出し、試験の質を評価した。 1名の著者(RJ)は、発表された報告で見つからないレビュー必要情報を得るために研究者に連絡を取った。

主な結果

78例の参加者を対象とした1件の適格な試験が確認された。男女とも(40~75歳)対象としていた。フォローアップは短く、12週間だけであった。

12週の治療後、無痛歩行距離はニンニク投与群では161mから207mに、プラセボ投与群では172mから203mに増加した。この結果からは、統計学的有意差は認められなかった。収縮期あるいは拡張期血圧、心拍数、足関節血圧や上腕血圧の変化に差はなかった。重篤な副作用は認められず、ニンニクを投与した9例の患者(28%)とプラセボを投与した4例の患者(12%)がニンニクの強いにおいを訴えた。

3件の試験は、臨床的な測定を含まないため除外した。

著者の結論

1件の短期間の小規模試験の結果、ニンニクが歩行距離に対して統計学的に有意な効果を及ぼさないことが確認された

訳注

《実施組織》厚生労働省「「統合医療」に係る情報発信等推進事業」(eJIM:http://www.ejim.ncgg.go.jp/)[2015.12.22] 《注意》この日本語訳は、臨床医、疫学研究者などによる翻訳のチェックを受けて公開していますが、訳語の間違いなどお気づきの点がございましたら、eJIM事務局までご連絡ください。なお、2013年6月からコクラン・ライブラリーのNew review, Updated reviewとも日単位で更新されています。eJIMでは最新版の日本語訳を掲載するよう努めておりますが、タイム・ラグが生じている場合もあります。ご利用に際しては、最新版(英語版)の内容をご確認ください。

Plain language summary

Garlic for peripheral arterial occlusive disease affecting the legs

The most common symptom of peripheral arterial occlusive disease is intermittent claudication, discomfort in the legs that is triggered by exercise and relieved with rest. The underlying cause is atherosclerosis. Risk factors associated with the development of peripheral arterial disease include cigarette smoking, raised blood cholesterol and other fats (lipids), high blood pressure and diabetes. Garlic has been used as a medicinal therapy since ancient times. The main active ingredient is an unstable odorous sulphurous compound called allicin so that active ingredients may be lost in processing, and with different types of preparation. Commercially available preparations of garlic are reported to have beneficial effects on some of the risk factors for vascular disease. With fresh garlic, at least seven cloves of garlic per day are needed. Apart from the odour, garlic has only minor gastrointestinal side effects.

The review authors made a thorough search of the medical literature and found one controlled trial in which 78 participants with peripheral arterial occlusive disease were randomised to receive garlic or a placebo medication. The dose of garlic was two coated tablets of 200 mg oral standardised garlic powder twice daily. Both men and women, aged 40 to 75 years, were included although sixteen did not keep to their treatment.

After twelve weeks of treatment, pain-free walking distance increased similarly whether receiving garlic or placebo. Similarly there was no difference in the changes in blood pressure, heart rate and pressure differences between the ankle and brachial pressures. No severe side effects were observed although more people taking garlic (28%) than placebo (12%) complained of a noticeable garlic smell. Peripheral arterial occlusive disease is a long-term (chronic) condition and any improvements in symptoms would require longer-term treatment and follow up than in this study.

Résumé simplifié

L'ail pour lartériopathie oblitérante des membres inferieurs

Le symptôme le plus courant lartériopathie oblitérante des membres inferieurs est la claudication intermittente, une gêne dans les jambes qui est provoquée par l'exercice et soulagée par le repos. L'athérosclérose en est la cause sous-jacente. Les facteurs de risque liés au développement de la maladie artérielle périphérique comprennent le tabagisme, une cholestérolémie élevée ainsi quune hyperlipidémie, une pression artérielle élevée et le diabète. L'ail est utilisé comme traitement médicamenteux depuis l'antiquité. Le principal ingrédient actif est un composé sulfureux odorant instable appelé « allicine », qui peut être perdu lors des différentes étapes de préparation. Des préparations commerciales d'ail sont rapportées pour avoir des effets bénéfiques sur certains des facteurs de risque de maladie vasculaire. Sept gousses d'ail frais par jour sont nécessaires au minimum. Mise à part lodeur donnée à lhaleine, l'ail présente seulement des effets gastro-intestinaux secondaires mineurs.

Les auteurs de la revue ont effectué une revue de la littérature médicale et ont identifié un essai contrôlé dans lequel 78 participants atteints dartériopathie oblitérante des membres inferieurs ont été randomisés pour recevoir de l'ail ou un médicament placebo. La dose de l'ail était de deux comprimés oraux enrobés de 200 mg de poudre d'ail standardisé deux fois par jour. Des hommes et femmes, âgés de 40 à 75 ans, ont été inclus, bien que seize aient arrêté leur traitement.

Après douze semaines de traitement, la distance de marche sans douleur augmentait indifféremment dans les deux groupes. De même, il n'y avait aucune différence dans les changements de la pression artérielle, la fréquence cardiaque et de la différence entre les pressions brachiales et à la cheville. Aucun effet secondaire grave n'a été observé, bien que davantage de personnes prenant de l'ail (28 %) que le placebo (12 %) se sont plaints d'une forte odeur d'ail. Lartériopathie oblitérante des membres inferieurs est une affection à chronique et toute amélioration des symptômes nécessiteraient un traitement et un suivi plus long terme que dans cette étude.

Notes de traduction

Traduit par: French Cochrane Centre 1st December, 2013
Traduction financée par: Pour la France : Minist�re de la Sant�. Pour le Canada : Instituts de recherche en sant� du Canada, minist�re de la Sant� du Qu�bec, Fonds de recherche de Qu�bec-Sant� et Institut national d'excellence en sant� et en services sociaux.

平易な要約

下肢に影響を及ぼす末梢動脈閉塞性疾患に対するニンニク

末梢動脈閉塞性疾患の最も一般的な症状は間欠性跛行で、下肢に感じる不快感は運動によって引き起こされ、安静にしていると和らぐ。根底にある原因はアテローム動脈硬化症である。 末梢動脈疾患発症に関連する危険因子には、喫煙、血中コレステロール値やその他の脂肪(脂質)の上昇、高血圧、糖尿病などがある。ニンニクは、古代から薬物療法として使用されてきた。主な有効成分はアリシンと呼ばれる不安定な臭気性硫黄化合物なので、処理中に有効成分が失われる可能性がある。この成分には、さまざまな種類の製剤がある。ニンニクの市販製剤は、血管障害の一部の危険因子に有益な効果をもたらすことが報告されている。一日に7片以上の新鮮なニンニクが必要である。においを除き、ニンニクは胃腸障害の副作用をほとんど生じない。

レビュー著者は、医学文献を徹底的に検索した結果、末梢動脈閉塞性疾患に罹患した78例の参加者をニンニク投与群とプラセボ投与群にランダム化した1件の比較試験を確認した。ニンニクは、標準化された経口用ニンニク粉末200mgコーティング錠を1日に2回投与した。40~75歳の男女を対象としたが、16例は治療に従わなかった。 12週の治療後、無痛歩行距離はニンニク投与群もプラセボ投与群も同様に増加した。同じく、血圧、心拍数および足関節血圧と上腕血圧の変化に差は認められなかった。 ニンニク投与群の方(28%)がプラセボ投与群(12%)よりもニンニクの強いかおりを訴えたが、重篤な副作用は確認されなかった。末梢動脈閉塞性疾患は長期(慢性)疾患で、症状の改善には本研究よりも長期の治療とフォローアップが必要であると思われる。

訳注

《実施組織》厚生労働省「「統合医療」に係る情報発信等推進事業」(eJIM:http://www.ejim.ncgg.go.jp/)[2015.12.22] 《注意》この日本語訳は、臨床医、疫学研究者などによる翻訳のチェックを受けて公開していますが、訳語の間違いなどお気づきの点がございましたら、eJIM事務局までご連絡ください。なお、2013年6月からコクラン・ライブラリーのNew review, Updated reviewとも日単位で更新されています。eJIMでは最新版の日本語訳を掲載するよう努めておりますが、タイム・ラグが生じている場合もあります。ご利用に際しては、最新版(英語版)の内容をご確認ください。

Laički sažetak

Češnjak za liječenje okluzivne bolesti perifernih arterija na nogama

Najčešći simptomi okluzivne bolesti perifernih arterija su intermitentna klaudikacija (povremena pojava boli, utrnulosti i šepanja u jednoj ili obje noge) i neugodan osjećaj u području nogu potaknuta tjelesnom aktivnošću, a smanjuje se jedino mirovanjem. Pozadinski uzrok je ateroskleroza. Rizični faktori povezani s razvojem bolesti perifernih arterija uljučuju cigarete, pušenje, povećani kolesterol i masnoće u krvi, visoki krvni tlak i dijabetes. Češnjak se koristi u terapijske svrhe još od davnih vremena. Glavni aktivni sastojak je nestabilna sumporna tvar neugodna mirisa zvana allicin čiji se aktivni sastojci mogu izgubiti prilikom pripreme lijeka, ovisno o vrsti pripreme. Za komercijalno dostupne pripravke češnjaka opisani su pozitivni učinci na neke rizične faktore bolesti krvnih žila (vaskularne bolesti). Kada je u pitanju svježi češnjak, potrebno je uzeti najmanje sedam režanja češnjaka na dan. Osim neugodnog mirisa, češnjak ima tek nekoliko blagih probavnih nuspojava.

Autori ovog Cochrane sustavnog pregleda pretražili su medicinsku literaturu. Pronađeno je jedno kontrolirano ispitivanje u kojem su 78 sudionika s bolesti perifernih arterija nasumično razvrstano te su jedni liječeni češnjakom, a drugi placebo lijekom. Doza češnjaka je bila dvije filmom obložene tablete od 200 mg standardiziranog praha češnjaka koje se uzimaju na usta (oralno) dva puta dnevno. Istraživanje je uključivalo i muškarce i žene u dobi od 40 do 75 godina, od kojih se šesnaest nisu pridržavali uputa do kraja terapije.

Nakon dvanaest tjedana terapije, razdoblje bez bolova se povećalo jednako kod pacijenata koji su primali češnjak kao i kod onih koji su primali placebo lijek. Također, nije bilo razlike u promjenama krvnog tlaka, otkucajima srca kao ni razlikama u bolovima među nožnih i ručnih zglobova. Nisu primjećene nikakve ozbiljne nuspojave iako se više ispitanika koji su primali češnjak (28%) u odnosu na one koji su primali placebo lijekove potužilo na karakterističan neugodan miris češnjaka. Bolest perifernih arterija je dugotrajno (kronično) stanje i za bilo koje poboljšanje u simptomima bolesti potrebno je dulje liječenje za razliku od duljine terapije analizirane u uključenom istraživanju.

Bilješke prijevoda

Hrvatski Cochrane
Preveo: Ante Jović
Ovaj sažetak preveden je u okviru volonterskog projekta prevođenja Cochrane sažetaka. Uključite se u projekt i pomozite nam u prevođenju brojnih preostalih Cochrane sažetaka koji su još uvijek dostupni samo na engleskom jeziku. Kontakt: cochrane_croatia@mefst.hr

Background

Peripheral arterial occlusive disease primarily affects the major arteries of the lower limb. The most common symptom in early occlusive disease is intermittent claudication - discomfort in the legs induced by exercise and relieved by rest. Numerous risk factors have been associated with the development of peripheral arterial disease, including cigarette smoking, raised blood lipids, hypertension and diabetes.

The medicinal use of garlic can be traced back to Egyptian times. The primary active component of garlic is an unstable odorous sulphurous compound called allicin. Meta-analysis of commercially available preparations of garlic have been reported to have beneficial effects on some of the risk factors associated with atherosclerosis such as serum cholesterol (Silagy 1994; Warshafsky 1993). With fresh garlic, the dosages needed to inhibit platelet aggregation or lower cholesterol levels are unacceptably high; at least seven cloves of garlic per day (Kleijnen 1989).

Garlic is an acceptable therapy to the general population and, apart from the odour, has only minor gastrointestinal side effects. Trials with endpoints more meaningful and relevant than laboratory endpoints, however, are necessary before claiming that garlic improves health. Many trials have been carried out to assess its efficacy in the treatment and risk reduction of coronary atherosclerosis, but few trials have been carried out in people with peripheral vascular disease.

The purpose of this review is to assess the efficacy of garlic therapy in improving the morbidity associated with peripheral arterial occlusive disease. The relevant trials of garlic have been considered. As one of the difficulties in showing the effectiveness of garlic is that active ingredients may be lost in processing, the type of preparation (i.e. fresh, powdered or non-powdered) has been taken into consideration.

Objectives

To establish the effectiveness of garlic in the treatment of peripheral arterial occlusive diseases.

We wished to test the following hypotheses:

a) That commercially prepared garlic preparations have a beneficial effect on the morbidity associated with peripheral arterial occlusive disease;

b) That the magnitude of the effects observed with dried garlic is greater than with non-powder preparations in the treatment of peripheral arterial occlusive disease.

Methods

Criteria for considering studies for this review

Types of studies

We assessed randomised controlled trials of garlic versus placebo for the treatment of peripheral arterial occlusive disease. As there are currently only a few trials in this area, any trials identified in future that either use alternation (e.g. allocation by date of birth or days of the week) or that have not been analysed on an intention-to-treat basis (as long as all randomised patients were accounted for) will be included. Blinding of participants is a particular problem in garlic trials because of its characteristic smell.

Types of participants

People with peripheral arterial occlusive disease were included. Most participants had intermittent claudication (diagnosed either by questionnaire or clinically), but those with critical limb ischaemia and asymptomatic disease identified by testing (angiography, ankle pressures, etc.) were also eligible.

People with aortic disease and no peripheral arterial disease were excluded.

Types of interventions

Any trial of garlic therapy for the treatment of peripheral arterial occlusive disease was considered. Since one of the difficulties in showing the effectiveness of garlic is that active ingredients may be lost in processing, the type of preparation (i.e. fresh, powdered or non-powdered) was taken into consideration.

Types of outcome measures

Two main outcome measures were considered: objective measures of progression of underlying atherosclerosis (e.g. ankle pressure measurements, treadmill testing, angiography); and subjective measures (e.g. symptom progression).

Search methods for identification of studies

Electronic searches

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (last searched January 2013) and the Cochrane Central Register of Controlled Trials (CENTRAL) 2012, Issue 12, part of The Cochrane Library (www.thecochranelibrary.com). See Appendix 1 for details of the search strategy used to search CENTRAL. The Specialised Register is maintained by the TSC and is constructed from weekly electronic searches of MEDLINE, EMBASE, CINAHL, AMED, and through handsearching relevant journals. The full list of the databases, journals and conference proceedings which have been searched, as well as the search strategies used are described in the (Specialised Register) section of the Cochrane Peripheral Vascular Diseases Group module in The Cochrane Library (www.thecochranelibrary.com).

Searching other resources

The reference lists of relevant studies were screened for additional studies and citation tracking of any relevant trials was carried out.

Data collection and analysis

Selection of trials

Ruth Jepson selected trials for possible inclusion in the review and sought additional information from the principal investigators of all trials.

Assessment of methodological quality

Ruth Jepson and Jos Kleijnen independently assessed the methodological quality of trials using a standard scoring sheet developed by the Cochrane PVD Review Group. Any discrepancies were considered by Gill Leng until a consensus decision could be made.

Data extraction

For the one included trial, information was collected about the method of randomisation, blinding and whether an intention-to-treat analysis could possibly be done. Ruth Jepson and Jos Kleijnen extracted data independently to ensure quality control. Self-designed forms were used for the data extraction in accordance with Cochrane guidelines.

Statistical analysis

If more trials become available in the future, the heterogeneity between trial results will be tested. Such tests will be subjective, by clinical judgement of differences in patient populations, interventions and outcome assessments, and objective, using appropriate statistical tests. Depending on the results of the heterogeneity assessments, part of the outcomes may be pooled statistically using relevant techniques.

Results

Description of studies

Included studies

Only one trial (Keisewetter 1993) was identified that fulfilled the criteria for inclusion in the review. Summary details of this trial are given in the 'Characteristics of included studies' table. The trial was relatively small with only 80 patients being randomised and 16 of these did not show sufficient compliance. The duration of the trial was 12 weeks. Further details were requested from the principal author, but no reply was received.

Excluded studies

One trial (Koscielny 1999) was excluded because it only measured arteriosclerotic effects and not clinical symptoms. In addition, the subject population was described as 'probationers', and it was not clear if these were healthy volunteers or people with pre-existing disease. Two trials (Larijani 2013; Kieswetter 1997) were excluded because they did not include objective measures of progression of underlying atherosclerosis (e.g. ankle pressure measurements, treadmill testing) or subjective measures (e.g. symptom progression).

Risk of bias in included studies

The one included study (Keisewetter 1993) was randomised, double-blinded and placebo-controlled. There was no mention of the method of randomisation, nor the concealment of allocation (score B). Inclusion and exclusion criteria were adequate, but the trial was of short duration (only 12 weeks). No intention-to-treat analysis was used for the sixteen patients who did not complete the study.

Effects of interventions

The weighted mean difference and a fixed-effect model were used to test the significance of the results. The mean difference between the two groups at the end of treatment was analysed rather than the mean change within the two groups before and after treatment. After twelve weeks of treatment, pain-free walking distance increased from 161 to 207 metres in the garlic group and from 172 to 203 metres in the placebo group. There was no difference in change of systolic or diastolic blood pressure, heart rate, ankle and brachial pressures. No severe side effects were observed but nine patients taking garlic (28%) and four patients taking placebo complained of a noticeable garlic smell (12%). No studies were found comparing dried garlic with non-powder preparations.

Discussion

The only included study was small and of short duration (12 weeks). Although no statistically significant improvement was found overall, the authors of the trial report that there was a significant increase in walking distance, but this only occurred in the last weeks of therapy. Peripheral arterial occlusive disease is a chronic condition, and any subjective or objective improvement in outcomes would require longer term therapy and follow up.

Authors' conclusions

Implications for practice

One small trial of short duration found no statistically significant effect on walking distance. Thus, at this stage, garlic as a therapy for the treatment of peripheral arterial occlusive disease cannot be recommended.

Implications for research

Further trials of garlic therapy for the treatment of peripheral arterial occlusive disease are required to determine its effectiveness. These trials should be large and of reasonable duration.

Acknowledgements

We would like to thank Claire Allen (Consumer Representative, Complementary & Alternative Medicine Field) for her very useful comments on the review. We would also like to thank the Cochrane Consumer Network for supplying the Plain Language Summary.

Data and analyses

Download statistical data

Comparison 1. Garlic versus placebo
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Pain-free walking distance1 Mean Difference (IV, Fixed, 95% CI)Totals not selected
Analysis 1.1.

Comparison 1 Garlic versus placebo, Outcome 1 Pain-free walking distance.

Appendices

Appendix 1. 2013 CENTRAL search strategy

#1MeSH descriptor: [Arteriosclerosis] this term only890
#2MeSH descriptor: [Arteriolosclerosis] this term only0
#3MeSH descriptor: [Arteriosclerosis Obliterans] this term only71
#4MeSH descriptor: [Atherosclerosis] this term only382
#5MeSH descriptor: [Arterial Occlusive Diseases] this term only753
#6MeSH descriptor: [Intermittent Claudication] this term only710
#7MeSH descriptor: [Ischemia] this term only751
#8MeSH descriptor: [Peripheral Vascular Diseases] this term only548
#9#1 or #2 or #3 or #4 or #5 or #6 or #7 or #8 3513
#10atherosclero* or arteriosclero* or PVD or PAOD or PAD 16775
#11(arter* or vascular or vein* or veno* or peripher*) near (occlus* or steno* or obstuct* or lesio* or block*) 7242
#12peripheral near/3 dis* 3203
#13claudic* 1426
#14isch* or CLI 16663
#15#1 or #2 or #3 or #4 or #5 or #6 or #7 or #8 or #9 or #10 or #11 or #12 or #13 or #14 37512
#16MeSH descriptor: [Garlic] explode all trees121
#17MeSH descriptor: [Allium] this term only5
#18(garlic or allium or allicin or allicor) 303
#19#16 or #17 or #18 303
#20#15 and #19 in Trials34

What's new

Last assessed as up-to-date: 16 January 2013.

DateEventDescription
11 April 2013Review declared as stableThis Cochrane review has been marked stable and will only be updated when new studies are identified.

History

Protocol first published: Issue 2, 1996
Review first published: Issue 3, 1997

DateEventDescription
15 February 2013New search has been performedSearches were rerun. No additional included studies but two additional studies were excluded.
15 February 2013New citation required but conclusions have not changedSearches were rerun. No additional included studies but two additional studies were excluded. Conclusions not changed.
12 May 2008AmendedConverted to new review format.
14 November 2007New search has been performedNo new trials found. Conclusions remain unchanged.
21 November 2006New search has been performedAdded Plain Language Summary. No new trials found.
11 July 2005New search has been performedNo new trials found. Review updated without change.
26 May 2004New search has been performedReview updated without change. No new studies found.
4 April 2003New search has been performedOne new study excluded, no change to conclusions.

Contributions of authors

Ruth Jepson: selected trials for inclusion; sought additional information from the principal investigators of all trials; assessed trials for quality; extracted data; wrote text; revised review (April 2003).

Jos Kleijnen: assessed trials for quality; extracted data.

Gillian Leng: resolved disagreements between RJ and JK regarding trial quality.

The Peripheral Vascular Diseases Review Group assisted with searching for trials for this review.

Declarations of interest

JK reports that Kleijnen Systematic Reviews Ltd has received project funding from various pharmaceutical companies for work in unrelated areas.

Sources of support

Internal sources

  • No sources of support supplied

External sources

  • Chief Scientist Office, Scottish Government Health Directorates, The Scottish Government, UK.

    The PVD Group editorial base is supported by the Chief Scientist Office.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Keisewetter 1993

  1. a

    PAOD: peripheral arterial occlusive disease
    PFWD: pain-free walking distance

Methods

Study design: Randomised, placebo controlled, double-blind single centre trial.

Method of randomisation: not stated.

Exclusions post-randomisation: Not stated.

Losses to follow up: 8 patients in each group (out of a total of 78 patients).

Participants

Participants: men and women aged 40 to 75 years.

Country: Germany.

Inclusion criteria: femoral and/or tibial type PAOD; angiographically-localised stenosis or occlusion of the superficial femoral artery free vascular system of the popliteal artery (stenosis under 60% was excluded); mean stable PFWD between 80 and 300 metres; Doppler pressure values over peripheral arteries at rest greater than 50 mm Hg, and haematocrit values up to 47%.

Exclusion criteria: arterial occlusion of the pelvic type in the lower extremities (or stenosis over 60%); endangiitis obliterans; nonvascular walking impediment; operations within the preceding 3 months; history of a cerebral infarction with gait disturbances; severe cerebral insufficiency; polyneuropathy; cardiac infarction within the past 6 weeks; unstable angina pectoris, crescendo angina, angina CCS stage III; cardiac insufficiency stage II or IV; haemodynamically relevant valvular heart defect*; arrhythmia Lown IVb and V; higher degree SA and AV blocks; heart rate at rest below 50 per min or over 100 per min; chronic venous insufficiency; inadequately compensated severe internal diseases; cerebral spasms; intake of anticoagulants, rheological or vasoactive drugs, analgesics and antiphlogistic intake not discontinued for at least 4 weeks prior to the study; readjustment or correction of therapy with cardiac glycosides, diuretics, antidiabetics, antiarrhythmics, calcium antagonists; Doppler pressure values over peripheral arteries below 50 mm Hg.

Interventions

Treatment: 2 x 2 coated tablets of 200 mg oral standardised garlic powder (Kwai, Sapec).

Control: Placebo tablets.

Duration of trial: 12 weeks.

Outcomes

Primary: PFWD.

Secondary: Diastolic blood pressure, cholesterol concentrations, rheological parameters, side effects.

NotesOriginal article states 'hemodynamically relevant valvular nearby defect'.
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskB - Unclear

Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion
Kieswetter 1997Did not include objective measures of progression of underlying atherosclerosis (e.g. ankle pressure measurements, treadmill testing) or subjective measures (e.g. symptom progression).
Koscielny 1999Only measured anti-atherosclerotic effects such as plaque volume. Did not include any clinical measurements such as walking distances. Also, not clear who the study population was (only described as 'probationers').
Larijani 2013Did not include objective measures of progression of underlying atherosclerosis (e.g. ankle pressure measurements, treadmill testing) or subjective measures (e.g. symptom progression).