Nature Communications: A Short Oatmeal-Based Diet Improves Cholesterol Levels and Metabolism

A new study published in Nature Communications has shown that a short-term oatmeal-based diet can significantly improve levels of “bad” cholesterol and other markers of metabolic health in people with metabolic syndrome—a combination of excess weight, high blood pressure, and metabolic disturbances, including elevated blood sugar and blood lipid levels.

During the trial, participants consumed almost exclusively oatmeal for two days: they were given 300 grams of oatmeal cooked in water three times a day, with only small amounts of fruits or vegetables allowed. The total caloric intake was roughly half of their usual diet. The control group also followed a calorie-restricted diet but without oatmeal.

Those who followed the oatmeal diet saw their LDL cholesterol (“bad” cholesterol) levels drop by about 10% compared with the control group—a substantial improvement comparable in magnitude to the effect of some modern medications, though not identical in strength. Participants also lost an average of around 2 kilograms in body weight, and their blood pressure decreased slightly.

The mechanism appears particularly interesting: researchers observed that oatmeal promoted the growth of certain gut bacteria that, when breaking down oats, produced phenolic metabolites that had beneficial effects on lipid metabolism.

Previous studies have shown that beta-glucan, the soluble fiber found in oats, can lower cholesterol levels by influencing the gut microbiome and bile acid metabolism.

The effects persisted for at least six weeks after the two-day intervention, suggesting that short “oatmeal” diets, if repeated periodically, could be a pleasant and well-tolerated way to help maintain healthy cholesterol levels and reduce the risk of developing diabetes.

The authors note that the findings are especially relevant for people with metabolic syndrome, in whom elevated LDL cholesterol and excess body weight increase the risk of cardiovascular disease.