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People who consumed a serving a day of dietary "pulses" -- such as beans, chickpeas, lentils and peas -- significantly reduced their low-density lipoprotein (LDL) cholesterol, a meta-analysis concluded.

Those whose diets included a median pulse intake of 130 g/d had lower LDL cholesterol levels than those on a control diet (mean difference -0.17 mmol/L, 95% CI -0.25 to -0.09), according to , of the University of Toronto in Canada, and his co-authors.

The results were "equivalent to a reduction of about 5% from baseline" and consistent with the results of two previous meta-analyses, they wrote online in .

"This is important especially for patients with hypercholesterolemia who prefer dietary approaches to managing their cholesterol levels, or for those who cannot tolerate statin therapies," wrote Sievenpiper and his colleagues.

The researchers found no effect on apolipoprotein B and nonhigh-density lipoprotein (non-HDL) cholesterol.

The analysis included 26 randomized controlled trials, each of which lasted at least 3 weeks and compared a diet that emphasized pulse intake with an isocaloric diet that did not included pulses.

The studies included both healthy people and those with hyperlipidemia, the majority of who were middle-age. Dietary pulse intake was not the sole intervention in some of the trials, and the goal of some trials was weight loss, the authors said.

A variety of pulses were studied, with beans being the most common form. In some cases, the pulses were administered as whole foods, while other studies relied on flour made from pulses or a mix of whole foods and pulse flours.

Inter-study heterogeneity was high (I²=80%). "The sensitivity analysis didn't identify any particular study "as exerting undue influence on the overall results," the authors said.

"A post-hoc subgroup analysis by sex, however, did show that studies that included men tended to show a greater reduction in LDL cholesterol than those with more women, with a corresponding reduction in the I² value from 80% in our primary analysis to 53%," the authors wrote.

Men may have responded more favorably to the intervention because they tend to have higher levels of LDL cholesterol than women "and they tend to have poorer dietary habits and thus better responses to healthier diets," the authors said.

The results are significant despite the inter-study heterogeneity, the authors said, citing a of 19 trials comparing statin use and nonstatin use with dietary interventions.

In that study, a 1% reduction in LDL cholesterol translated to a 1% reduction in cardiovascular mortality, the authors said. "Therefore, the reduction of 5% observed in our meta-analysis suggests a potential risk reduction of 5%-6% in major vascular events," they wrote.

The biggest challenge, the authors said, may be getting people to consume enough of pulses to make the impact. Many people, they said, consume far less than the 130 g/d observed in the study.

"The current median intake level in the United States is 0.2 servings daily, and in Canada only 13% consume dietary pulses on any given day, with a median intake of only about 0.5 servings daily among those who do consume them," the authors said.

There were limitations to the study beyond the inter-study heterogeneity, including possible publication bias, and the fact that most of the trials were of low methodological quality, and short in duration.

Future trials should be longer, designed better, and include plans to assess apolipoprotein B and non-HDL cholesterol, the authors said. What's more, they said, future meta-analyses should evaluate the effects of dietary interventions on metabolic risk factors, which also contribute to cardiovascular disease.

From the American Heart Association:

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