Whole grain cereals for the primary or secondary prevention of cardiovascular disease

• Published in: Cochrane database of systematic reviews 2017-08, Vol.8 (8), p.CD005051-CD005051
• Main Authors: Kelly, Sarah Am, Hartley, Louise, Loveman, Emma, Colquitt, Jill L, Jones, Helen M, Al-Khudairy, Lena, Clar, Christine, Germanò, Roberta, Lunn, Hannah R, Frost, Gary, Rees, Karen
• Format: Article
• Language: English
• Subjects: Adult; Aged; B. Stable Ischemic Heart Disease (secondary prevention, treatment, control); Cardiovascular Diseases - blood; Cardiovascular Diseases - prevention & control; Cholesterol - blood; Cholesterol, HDL - blood; Cholesterol, LDL - blood; Complementary & alternative medicine; Coronary Disease - blood; Coronary Disease - diet therapy; Edible Grain; Heart & circulation; Humans; Middle Aged; Randomized Controlled Trials as Topic; Risk Factors; Triglycerides - blood
• ISSN: 1469-493X
• DOI: 10.1002/14651858.CD005051.pub3

There is evidence from observational studies that whole grains can have a beneficial effect on risk for cardiovascular disease (CVD). Earlier versions of this review found mainly short-term intervention studies. There are now longer-term randomised controlled trials (RCTs) available. This is an update and expansion of the original review conducted in 2007. The aim of this systematic review was to assess the effect of whole grain foods or diets on total mortality, cardiovascular events, and cardiovascular risk factors (blood lipids, blood pressure) in healthy people or people who have established cardiovascular disease or related risk factors, using all eligible RCTs. We searched CENTRAL (Issue 8, 2016) in the Cochrane Library, MEDLINE (1946 to 31 August 2016), Embase (1980 to week 35 2016), and CINAHL Plus (1937 to 31 August 2016) on 31 August 2016. We also searched ClinicalTrials.gov on 5 July 2017 and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) on 6 July 2017. We checked reference lists of relevant articles and applied no language restrictions. We selected RCTs assessing the effects of whole grain foods or diets containing whole grains compared to foods or diets with a similar composition, over a minimum of 12 weeks, on cardiovascular disease and related risk factors. Eligible for inclusion were healthy adults, those at increased risk of CVD, or those previously diagnosed with CVD. Two review authors independently selected studies. Data were extracted and quality-checked by one review author and checked by a second review author. A second review author checked the analyses. We assessed treatment effect using mean difference in a fixed-effect model and heterogeneity using the I statistic and the Chi test of heterogeneity. We assessed the overall quality of evidence using GRADE with GRADEpro software. We included nine RCTs randomising a total of 1414 participants (age range 24 to 70; mean age 45 to 59, where reported) to whole grain versus lower whole grain or refined grain control groups. We found no studies that reported the effect of whole grain diets on total cardiovascular mortality or cardiovascular events (total myocardial infarction, unstable angina, coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, total stroke). All included studies reported the effect of whole grain diets on risk factors for cardiovascular disease including blood lipids and blood pressure. All stud