Clinical question
How effective are wholegrain foods or diets on total mortality, cardiovascular (CV) events, and CV risk factors in healthy people or people who have established CV disease or related risk factors?
Bottom line
None of the randomised controlled trials (RCTs) looked at the effect of wholegrain diets or foods on CV mortality or events. Studies did look at the effect of wholegrains on lipids and blood pressure but found no evidence to support an effect, and most studies were at unclear or high risk of bias. Studies followed participants for 12–16 weeks. The age range of participants was from 24 to 70 years. The results from this review did not support changing the dietary habits of patients for short periods of time to obtain better control of CV risk factors.
Caveat
Most of the included studies had a number of methodological uncertainties, and all of the included studies were at high or unclear risk of bias. However, heterogeneity was low or non-substantial. The duration of interventions included in the review was short, sample sizes were small and many trials had a large number of dropouts. Adverse events were generally not reported. Seven of the studies reported funding or partial funding from organisations with commercial interests in cereals.
Context
There is evidence from observational studies that wholegrains can have a beneficial effect on risk for CV disease. Earlier versions of this review found mainly short-term intervention studies. There are now longer-term RCTs available.
Cochrane Systematic Review
Kelly SAM et al. Whole grain cereals for the primary or secondary prevention of cardiovascular disease. Cochrane Reviews, 2017, Issue 8. Art. No.: CD005051.DOI: 10.1002/14651858. CD005051.pub3. This review contains 9 studies involving 1414 participants.
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