Oats Cut Cholesterol, But Evidence for Whole Grains Lags

Whole-grain oats can carry the lipid-lowering banner higher than other whole grains -- but not too high.
So found a Cochrane review by Sarah Kelly, Ph.D., of the University of Teesside here, and colleagues. They reported that observational studies have made the case for the beneficial effects of whole grains against coronary heart disease risk factors, but clinical trials have lagged behind.
The trials have provided evidence for LDL reduction only by whole-grain oats, and even then only in the short term, the Cochrane group found in a meta-analysis.
Whole-grain oats significantly lowered total (-0.20 mmol/L, P=0.0001) and low-density lipoprotein cholesterol (-0.18 mmol/L, P<0.0001) over four to eight weeks, the investigators said.
"There is enough evidence for whole grain oats to suggest that healthcare professionals could recommend oats as part of cholesterol-reduction programs," they wrote.
However, they cautioned that despite the consistency of the whole grain oats findings, the 10 trials were short, of poor quality, underpowered, and funded by companies that stood to gain from the results.
"There is a need for well-designed, adequately powered, longer term randomized controlled studies in this area," they wrote. "In particular there is a need for randomized controlled trials on wholegrain foods and diets other than oats."
The authors acknowledged several epidemiological studies that have examined the association between the intake of wholegrain foods and the risk for coronary heart disease: The Iowa Women's Health study, reported in 1999, found greater intake of whole grains associated with reduced risk of death from coronary heart disease. In the same year, the Nurses' Health Study indicated wholegrain intake lowered risk of developing coronary heart disease.
In 2003 the Atherosclerosis Risk in Communities (ARIC) study showed whole grain consumption reduced risk of overall mortality and coronary artery disease incidence. And in 2002, the Framingham Offspring Study found diets rich in whole grains inversely associated with total cholesterol, LDL cholesterol and body mass index.