A new analysis of heart health studies has criticised policy makers for failing to promote wholegrain foods sufficiently. The meta-analysis combined data from seven observational studies, involving a total of 149,000 subjects. It was found that subjects eating at least 2.5 servings of wholegrains per day experienced a 21% reduction in the risk of heart disease or stroke compared with subjects who ate only 0.2 servings per day.
When the subjects were split by gender, the results were similar – an 18% risk reduction for men and a 21% risk reduction for women. There were no differences in cardiovascular disease risk when the researchers looked at consumption of refined grains.
The findings are based on epidemiology (science that studies the distribution of disease in large populations) and should be viewed with caution until supported by randomised controlled trials, where treatments are allocated to subjects at random (the most reliable form of scientific evidence to establish a causal effect). Nevertheless, there are plausible reasons why wholegrains could protect against cardiovascular disease. Firstly, they are a source of many biologically active components, such as B vitamins, minerals, lignans and phytosterols. Secondly, they contain fibre. However, many consumers and health professionals are unaware of these attributes.
As the researchers noted: "These biological agents influence cardiovascular risk through effects on glucose homeostasis, lipids and lipoproteins, endothelial function, and other mechanisms, potentially accounting for much of the observed benefit of high intake of whole grains".
For more information, see
Mellen PB et al (2007). Whole grain intake and cardiovascular disease: A meta-analysis. Nutrition, Metabolism & Cardiovascular Diseases. Apr 19; [Epub ahead of print].
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