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Sweet potato for type 2 diabetes mellitus

  1. Cheow Peng Ooi1,*,
  2. Seng Cheong Loke2

Editorial Group: Cochrane Metabolic and Endocrine Disorders Group

Published Online: 3 SEP 2013

Assessed as up-to-date: 20 FEB 2013

DOI: 10.1002/14651858.CD009128.pub3


How to Cite

Ooi CP, Loke SC. Sweet potato for type 2 diabetes mellitus. Cochrane Database of Systematic Reviews 2013, Issue 9. Art. No.: CD009128. DOI: 10.1002/14651858.CD009128.pub3.

Author Information

  1. 1

    Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Endocrine Unit, Department of Medicine, Serdang, Selangor DE, Malaysia

  2. 2

    Universiti Putra Malaysia, Institute of Gerontology, Serdang, Selangor DE, Malaysia

*Cheow Peng Ooi, Endocrine Unit, Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor DE, 43400, Malaysia. cpooi07@gmail.com.

Publication History

  1. Publication Status: Edited (no change to conclusions), comment added to review
  2. Published Online: 3 SEP 2013

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Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. Plain language summary

Background

Sweet potato (Ipomoea batatas) is among the most nutritious subtropical and tropical vegetables. It is also used in traditional medicine practices for type 2 diabetes mellitus. Research in animal and human models suggests a possible role of sweet potato in glycaemic control.

Objectives

To assess the effects of sweet potato for type 2 diabetes mellitus.

Search methods

We searched several electronic databases, including The Cochrane Library (2013, Issue 1), MEDLINE, EMBASE, CINAHL, SIGLE and LILACS (all up to February 2013), combined with handsearches. No language restrictions were used.

Selection criteria

We included randomised controlled trials (RCTs) that compared sweet potato with a placebo or a comparator intervention, with or without pharmacological or non-pharmacological interventions.

Data collection and analysis

Two authors independently selected the trials and extracted the data. We evaluated risk of bias by assessing randomisation, allocation concealment, blinding, completeness of outcome data, selective reporting and other potential sources of bias.

Main results

Three RCTs met our inclusion criteria: these investigated a total of 140 participants and ranged from six weeks to five months in duration. All three studies were performed by the same trialist. Overall, the risk of bias of these trials was unclear or high. All RCTs compared the effect of sweet potato preparations with placebo on glycaemic control in type 2 diabetes mellitus. There was a statistically significant improvement in glycosylated haemoglobin A1c (HbA1c) at three to five months with 4 g/day sweet potato preparation compared to placebo (mean difference -0.3% (95% confidence interval -0.6 to -0.04); P = 0.02; 122 participants; 2 trials). No serious adverse effects were reported. Diabetic complications and morbidity, death from any cause, health-related quality of life, well-being, functional outcomes and costs were not investigated.

Authors' conclusions

There is insufficient evidence about the use of sweet potato for type 2 diabetes mellitus. In addition to improvement in trial methodology, issues of standardization and quality control of preparations - including other varieties of sweet potato - need to be addressed. Further observational trials and RCTs evaluating the effects of sweet potato are needed to guide any recommendations in clinical practice.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. Plain language summary

Sweet potato for type 2 diabetes mellitus

Sweet potato (Ipomoea batatas) is a plant found in the tropical and subtropical belts and is one of the most nutritious tropical and subtropical vegetables. As well as being popular in cooking in countries in Asia-Pacific, Africa and North America, sweet potato is also used in traditional medicine for the treatment of diabetes mellitus. We decided to investigate whether there is enough evidence from medical trials to show whether sweet potato works as a treatment for diabetes. This review of randomised controlled trials found only three studies (with a total of 140 participants) that evaluated the effects of sweet potato for type 2 diabetes mellitus compared with a fake medicine (placebo). All these trials were of very low quality. Two studies with 122 participants showed improved long-term metabolic control of blood sugar levels as measured by glycosylated haemoglobin A1c (HbA1c) which was moderately lowered by 0.3% in participants who were given 4 g sweet potato tablets a day for three to five months. The duration of treatment ranged from six weeks to five months. No study investigated diabetic complications, death from any cause, health-related quality of life, well-being, functional outcomes or costs. Adverse effects were mostly mild, and included abdominal distension and pain. There are many varieties of sweet potatoes and sweet potato preparations. More trials are needed to assess the quality of the various sweet potato preparations as well as to evaluate further the use of different varieties of sweet potato in the diet of diabetic people.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. Plain language summary

Batat (slatki krumpir) za dijabetes tipa 2

Batat (slatki krumpir) za dijabetes tipa 2

Batat (Ipomoea batatas) je biljka tropskog i suptropskog pojasa te je jedna od najhranjivijih tropskih i suptropskih povrtnica. Osim njegove popularnosti u kuhinjama zemalja azijsko-pacifičke regije, Afrike i Sjeverne Amerike, batat se također koristi u narodnoj medicini za liječenje šećerne bolesti. Međutim aktualni dokazi ne podupiru korištenje ove biljke u liječenju šećerne bolesti. U ovom Cochrane sustavnom preglednom članku randomiziranih kontroliranih pokusa pronađene su samo tri studije niske kvalitete koje su ocjenjivale učinke batata za dijabetes tipa 2. Dvije studije sa 122 sudionika pokazale su poboljšanu dugoročnu metaboličku kontrolu mjerenjem glikoziranog hemoglobina A1c (HbA1c): uzimanje pripravaka od batata u dozi od 4 g dnevno kroz tri do pet mjeseci u usporedbi s placebom dovelo je do smanjenja HbA1c od -0.3%, što je statistički značajno, ali nije klinički relevantno. Liječenje batatom u ovim studijama trajalo je od šest tjedana do pet mjeseci, a sudjelovalo je ukupno 140 pacijenata s dijabetesom tipa 2. Ni jedna studija nije istraživala dijabetičke komplikacije, smrt od bilo kojeg uzroka, kvalitetu života povezanu sa zdravljem, dobrobit, funkcionalne ishode ili troškove. Nuspojave su bile uglavnom blage, a uključivale su nadimanje i bol u trbuhu. Postoje mnoge vrste i načini pripreme batata. Potrebno je provesti još pokusa za procjenu kvalitete različitih pripravaka od batata kao i za podrobniju ocjenu korištenja različitih vrsta batata u prehrani dijabetičara.

Translation notes

Translated by: Croatian Branch of the Italian Cochrane Centre
Translation Sponsored by: Ministry of Education, Science and Sports