Barley sits in the shadow of oats, but the trial evidence for the grain is real.
In a five-arm randomized crossover published in Frontiers in Nutrition in February 2023, 32 adults with moderately elevated LDL cholesterol ate 80 grams of barley or oat flakes for breakfast each day for three weeks.
Total and LDL cholesterol fell in every cereal arm compared with the white toast control. The average drop was 0.27 to 0.33 mmol/L for total cholesterol and 0.21 to 0.30 mmol/L for LDL, roughly a 5 to 7 percent reduction.
The numbers returned to baseline during the three-week washout periods between arms, so the grain has to stay in the rotation for the effect to hold.
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The mechanism is a soluble fiber called beta-glucan, which sits in the cell walls of barley and oats. Beta-glucan forms a gel in the gut that binds bile acids and pulls cholesterol out with them.
The 3-gram number
US regulators put a specific figure on how much of the fiber matters. Under 21 CFR 101.81, the FDA allows a health claim tying beta-glucan from whole oats or barley to a lower risk of coronary heart disease at daily intakes of 3 grams or more, as part of a diet low in saturated fat and cholesterol.
Barley flakes carry roughly 4 to 5 grams of beta-glucan per 100 grams. An 80-gram bowl at breakfast, the dose used in the 2023 crossover, already clears the FDA threshold.
Meta-analyses point to the same range. A 2016 pooled analysis in the European Journal of Clinical Nutrition found barley beta-glucan lowered LDL cholesterol by about 0.25 mmol/L across 14 randomized trials.
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What it may do to blood sugar
Barley also blunts how sharply blood sugar rises after a meal. In a randomized crossover trial published in Nutrients in January 2025, 16 healthy adults who ate barley preloads containing 4 to 6 grams of beta-glucan had a lower glucose peak and a lower one-hour glucose area under the curve than after white rice.
The barley with the most beta-glucan produced the biggest effect. Higher fiber, flatter curve.
A separate double-blind trial published in Nutrients in November 2024 tested a barley fiber powder in 67 healthy adults against a rice-flour placebo taken with 30 grams of glucose.
Blood glucose was significantly lower at 30 and 60 minutes, insulin release was reduced, and participants reported less hunger and more fullness on a visual analog scale one hour after the drink.
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Both trials were small and short, and the participants were healthy adults, not people with diabetes. The findings say the grain slows the sugar curve, not that it treats anything.
How to work it in
Barley shows up as pearl barley, hulled barley, barley flakes, barley flour, and quick-cook grits.
The USDA Agricultural Research Service has flagged the soluble fiber in barley for its cholesterol-lowering effect for years, based on work by research chemist Kay Behall at the ARS Diet and Human Performance Laboratory in Beltsville, Maryland.
Pearl barley cooks in about 25 to 30 minutes and swaps easily into recipes that would otherwise use rice or pasta.
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Flakes work in an overnight bowl with yogurt and fruit, or as a hot cereal. Anyone on cholesterol-lowering medication should talk to a doctor before making a large dietary change.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.