Recent research has introduced a straightforward yet potent diet that effectively maintains cholesterol levels.
Researchers from the University of Bonn discovered that just two days of consuming an almost entirely oatmeal-based diet led to a significant reduction in harmful cholesterol levels, with positive effects still evident six weeks afterward.
Published in the journal Nature Communications, these findings stem from a controlled trial involving individuals with metabolic syndrome—a common group of risk factors that encompasses excess weight, high blood pressure, elevated blood sugar, and unhealthy cholesterol levels.
Although none of the participants had diabetes, all were at an increased risk of developing it.
For two days, one group adhered to a simple plan: consuming oatmeal three times daily. The oats were prepared in water, with a small addition of fruits or vegetables allowed.
Participants consumed approximately 300 grams of oatmeal daily, reducing their overall calorie intake by around half. A control group also decreased their caloric intake but did not consume oats.
Both groups experienced certain health improvements; however, the oatmeal group showed remarkable results. Their levels of LDL cholesterol—the type most closely associated with heart disease—declined by about 10 percent in just 48 hours.
On average, participants also lost approximately two kilograms (around four and a half pounds), and their blood pressure decreased slightly. Importantly, the cholesterol reduction continued even after resuming their normal diets, with lower LDL levels remaining relatively stable six weeks later.
“This is a significant reduction,” stated Marie-Christine Simon, a professor of nutrition and microbiota at the University of Bonn. While this impact is not as drastic as what modern cholesterol-lowering medications can achieve, its effectiveness is notable, especially given the simplicity and brief duration of the oat-focused intervention.
High levels of LDL cholesterol can be hazardous as they may accumulate in the walls of blood vessels, forming plaques that narrow arteries. If these plaques break, they can lead to blood clots, heart attacks, or strokes. Even modest decreases in LDL cholesterol can reduce the risk of long-term cardiovascular issues.
The benefits of this two-day oat-centric diet were specifically seen in individuals with metabolic syndrome, which means further research is needed to confirm its effects on healthy individuals.
Professor Simon indicated that the cholesterol-lowering mechanism is probably applicable across a broader population. The decrease in LDL cholesterol is closely associated with compounds generated when gut microbes decompose oats—especially metabolites related to ferulic acid—a process that occurs in most people, albeit with varying efficiency.
“This suggests that the observed effects have a common mechanism, but their intensity may differ among different populations,” Simon explained to Newsweek.
“Individuals with metabolic syndrome might experience more significant improvements because they typically start with elevated cholesterol levels and altered metabolic regulation, leaving more potential for noticeable enhancement.”
Additional studies involving healthy individuals and various metabolic conditions are needed to better understand the extent of these benefits and who may benefit most, she added.
How can two days of oatmeal lead to such a long-lasting effect? The answer seems to lie in the gut. Researchers found that the oat-heavy diet altered the composition of the participants’ gut bacteria.
“We identified that consuming oatmeal increased the number of specific gut bacteria,” explained Linda Klümpen, another author of the study, also from the University of Bonn.
These bacteria release metabolic by-products that provide energy to gut cells and enhance their function. One such substance produced during the breakdown of oat components has previously been linked to healthier cholesterol metabolism. Simultaneously, other gut bacteria helped diminish compounds associated with insulin resistance, a crucial factor in the development of type 2 diabetes.
Interestingly, researchers also explored a less intensive approach: consuming a smaller amount of oats—approximately 80 grams per day—over the course of six weeks without reducing caloric intake.
This method resulted in only slight improvements, suggesting that a brief, concentrated oat “reset” paired with a temporary calorie cut may be more effective than merely incorporating small amounts of oats into a regular diet.
Researchers cautioned that oatmeal should not replace medications or professional medical advice.
“The next step is to determine whether repeating an intensive oat-based diet every six weeks has a lasting preventative effect,” Dr. Simon stated.
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Reference
Klümpen, L., Mantri, A., Philipps, M., Seel, W., Schlautmann, L., Yaghmour, M. H., Wiemann, V., Stoffel-Wagner, B., Coenen, M., Weinhold, L., Hasenauer, J., Fließwasser, T., Burgdorf, S., Thiele, C., Stehle, P., & Simon, M.-C. (2026). Cholesterol-lowering effects of oats induced by microbially produced phenolic metabolites in metabolic syndrome: A randomized controlled trial. Nature Communications, 17(1), 598. https://doi.org/10.1038/s41467-026-68303-9
