A short-term diet centered around oats may be more powerful than expected when it comes to lowering cholesterol.
A recent study from the University of Bonn, published in the journal Nature Communications, found that people with metabolic syndrome saw significant improvements in their cholesterol levels after eating mostly oatmeal for just two days.
Metabolic syndrome includes a mix of conditions like high body weight, high blood pressure, and high blood sugar and fat levels.
In the study, participants followed a calorie-reduced diet that consisted almost entirely of boiled oatmeal, along with small portions of fruits or vegetables. They consumed 300 grams of oats per day, spread across three meals. After two days, their LDL cholesterol—the “bad” kind—dropped by 10%. Even six weeks later, this benefit remained.
The results were compared to a control group that followed a different calorie-reduced diet without oats. Both groups experienced some improvements, but those who ate oats showed significantly better results. They also lost about two kilograms in weight and saw a slight drop in blood pressure.
Oats have long been known to support metabolic health. Over a century ago, German doctor Carl von Noorden used oats to treat patients with diabetes. Today, medications are more commonly used, and dietary approaches like this are often overlooked. But this study shows that oats still have a lot to offer.
The researchers also looked at how oats affect gut bacteria. They found that eating large amounts of oats changed the composition of the gut microbiome. This is important because gut bacteria play a key role in how our bodies process food and handle stress.
The study found that these bacteria broke down the oats into phenolic compounds like ferulic acid. This substance, previously shown in animal studies to help regulate cholesterol, appears to do the same in humans. Other bacteria used the amino acid histidine in a way that may prevent insulin resistance, a condition that often leads to type 2 diabetes.
Interestingly, the dramatic results came only from the high-dose, short-term oat diet. A separate group followed a more modest plan, eating 80 grams of oats daily for six weeks without any calorie restrictions. This group showed only small improvements.
The researchers now want to see whether repeating this short-term oat-focused diet every six weeks could offer long-term protection against high cholesterol and diabetes.
The trial involved 68 participants and used a randomized controlled design, which is a gold standard in research. Though participants knew what they were eating, the people who analyzed their samples and measurements were kept unaware of group assignments to avoid bias.
Stool and blood samples were taken before and after the diet changes to track bacterial changes and measure cholesterol and other health markers.
Overall, this study suggests that short bursts of high-oat diets could become a simple and effective tool in managing cholesterol and preventing chronic conditions like diabetes. Further research will explore how often such a diet should be repeated for long-term benefits.
If you care about heart health, please read studies about top 10 foods for a healthy heart, and how to eat right for heart rhythm disorders.
For more health information, please see recent studies about how to eat your way to cleaner arteries, and salt and heart health: does less really mean more?
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