Recent research has unveiled that consuming oats for every meal over just two days can reduce ‘bad’ cholesterol levels by as much as 10%. This finding emerged from a small clinical trial.
Remarkably, the positive effects persisted for six weeks after participants resumed their normal eating habits.
While the cholesterol reduction is noteworthy, the study’s most intriguing aspect revolves around the underlying cause of this change.
Researchers have linked specific molecules produced by gut bacteria when digesting oats to a significant decrease in low-density lipoprotein (LDL) levels, a type of cholesterol that increases the risk of cardiovascular diseases.
The trial, described in a study published in Nature Communications, included 15 men and 17 women diagnosed with metabolic syndrome.
Seventeen participants (six men and eleven women) followed a calorie-restricted diet made primarily of oatmeal. Over 48 hours, they consumed 100 grams of rolled oat flakes, prepared in water, three times a day. The only allowable additions were select fruits and vegetables; no salt, sugar, or sweeteners were permitted.
The remaining 15 participants served as a control group, also on a calorie-reduced ‘healthy’ diet but without oats.
Both groups had their caloric intake halved for two consecutive days before returning to their regular diets.
At the conclusion of the oat diet, the total cholesterol levels in the oat group had decreased by 8%, with LDL levels dropping by approximately 10%—a significantly greater reduction compared to the control group. Additionally, participants on the oatmeal diet experienced weight loss and a slight decrease in blood pressure.
“The reduction of particularly harmful LDL cholesterol by 10% in the oat group is noteworthy, though it may not entirely match the effects of modern medications,” remarks senior author Marie-Christine Simon, a food scientist at the University of Bonn in Germany.
Through analysis of blood plasma and fecal samples, the study provided evidence that an oatmeal-based diet enhances populations of gut bacteria that produce compounds associated with improved cholesterol metabolism.
“We discovered that consuming oatmeal increases certain beneficial gut bacteria,” leads author Linda Klümpen explained in a press release.
“For example, we identified that intestinal bacteria synthesize phenolic compounds by metabolizing oats.
“One of these compounds, ferulic acid, has demonstrated positive effects on cholesterol metabolism in animal studies. This appears to hold true for several other metabolic products from bacteria as well.”
The researchers further explored the impact of dihydroferulic acid—a byproduct of gut bacteria metabolizing oats—which showed potential in reducing cholesterol storage.
It is crucial to note that the trial results may not be applicable to everyone in the general population, as all participants were affected by metabolic syndrome, a condition characterized by excess weight, high blood pressure, and elevated blood sugar, which can lead to diabetes.
Nevertheless, since LDL levels remained below baseline for six weeks post-diet, the researchers believe they have uncovered a biological process that merits further examination.
The researchers also conducted a follow-up trial involving 17 volunteers consuming 80 grams of oats daily for six weeks without additional dietary restrictions, compared to 17 control participants who did not eat oats.
While some benefits were observed, the longer oatmeal regimen did not yield the same rapid decline in cholesterol levels.
Related: ‘Oatzempic’ Fad Isn’t a Weight-Loss Drug Alternative. Experts Explain Why.
The study received support from the German Cereal Processing, Milling and Starch Industries’ Association and a food company; however, the researchers assert that the funders played no role in the study’s design or analysis, nor declared any conflicts of interest.
Further research involving larger sample sizes is necessary to validate these results and explore how oats impact gut bacteria, cholesterol, and potentially even weight loss.
“Implementing a short-term oat-based diet at regular intervals could serve as a well-tolerated strategy for maintaining cholesterol levels within the normal range and might help prevent diabetes,” Simon concludes.
“The next step involves determining whether a repeated intensive oat-based diet every six weeks can provide a lasting preventive effect.”
The findings of this research have been published in Nature Communications.
