y?Kristina Fiore, Staff Writer, MedPage Today
Published: March 10, 2009
Reviewed?by?Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine.
* Explain to interested patients that a meta-analysis found barley consumption reduced total cholesterol, LDL cholesterol, and triglycerides compared with controls.
* Note that barley contains ?-glucan, a soluble fiber that has shown lipid-lowering effects in studies of oat, which also contains the fiber.
HARTFORD, Conn., March 10 -- Barley may play a role in reducing cardiovascular risk, a meta-analysis showed.
Patients who ate barley regularly had a statistically significant reduction in total cholesterol, LDL cholesterol, and triglycerides, Craig I. Coleman, Pharm.D., and colleagues reported online in the Annals of Family Medicine.
Because previous research has shown that reducing LDL cholesterol is associated with lowered coronary risk, the researchers said their findings are likely clinically significant as well.
"Health practitioners should feel comfortable recommending barley to their patients to help reduce total cholesterol and LDL cholesterol concentrations," they said.
Barley contains ?-glucan, a type of insoluble fiber that has been shown to lower cholesterol in patients who eat oats. But the effects of barley have not received as much attention, the researchers said.
So they analyzed eight randomized controlled trials that totaled 391 participants and evaluated the lipid-lowering effects of barley. Each study enrolled relatively few people (median 30), and had a short duration time (median four weeks).
But the meta-analysis showed that participants who consumed barley regularly had significantly greater reductions in total cholesterol (-13 mg/dL), LDL cholesterol (-10 mg/dL), and triglycerides (-12 mg/dL) than controls who did not eat the grain.
They noted that the reduction in total and LDL cholesterol is in line with findings for oat-derived ?-glucan, which was expected because both have similar concentrations of the fiber, at 3.5% to 5.9% of total dry matter.
However, there was no observed effect for HDL cholesterol -- only a nonsignificant increase of 1 mg/dL.
Also, no dose-response relationship could be established because only six of the eight studies reported ?-glucan dose, precluding enough statistical power to draw any conclusions.
However, studies that did report dose had a range of 3 g to 10 g of ?-glucan per day.
The observed cholesterol-lowering effects of barley observed in the present study are in line with the FDA recommendation of 3 g or more of soluble fiber daily to reduce the risk of heart disease, the researchers said.
They said the finding is also important because reductions were seen regardless of whether participants made substitutions in their diet. For example, if they replaced eggs with barley, it would be difficult to tell whether improvements in cholesterol resulted from a healthier diet or from barley.
"That significant reductions in total cholesterol and LDL cholesterol were seen regardless of whether diet modifications were mandated equally in both study groups helps guard against the issue of dietary substitution and strengthens the effects of barley use," the researchers said.
The findings "support the routine use of soluble fibers in the diets of adult patients with and without hypercholesterolemia."
Rice and wheat do not contain ?-glucan, but oats, psyllium, pectin, and guar gum do contain the soluble fiber.
The researchers said future study should include larger trials to assess the dose-response relationship of barley ?-glucan.
The researchers reported no conflicts of interest.