This 48-hour oatmeal diet could slash cholesterol and prevent diabetes

Eating a diet of mainly oatmeal for two days could slash your cholesterol, with beneficial effects lasting for at least six weeks, a study suggests. The radical diet was found to alter the balance of gut bacteria, encouraging the growth of certain microbes thought to play a role in metabolising cholesterol.

It also appeared to support microbes that eliminate the amino acid histidine, which has been linked to insulin resistance – a precursor to Type 2 diabetes. Two types of oatmeal diet were tested in a study involving 68 people. For the 48-hour diet, 17 people ate 300g of rolled oat flakes boiled in water per day and added only small amounts of fruit or vegetables.

Fifteen others also cut their calorie intake but did not eat oats. Both groups saw health benefits, but the effect was stronger among those eating oats.

Marie-Christine Simon, junior professor at the Institute of Nutritional and Food Science at the University of Bonn, Germany, said: « The level of particularly harmful LDL cholesterol fell by 10% for them.

« That is a substantial reduction, although not entirely comparable to the effect of modern medications. They also lost two kilos in weight on average and their blood pressure fell slightly.”

Writing in the journal Nature Communications, researchers said the cholesterol benefits were still visible six weeks later.

The effects of the 48-hour diet were assessed using blood samples, analysed for “bad” LDL-cholesterol levels and dihydroferulic acid, a compound thought to be produced by beneficial gut bacteria. Stool samples were also used to identify bacterial species.

Linda Klümpen, the study’s lead author, said: « We were able to identify that the consumption of oatmeal increased the number of certain bacteria in the gut. We were able to show that intestinal bacteria produce phenolic compounds by breaking down the oats.

“It has already been shown in animal studies that one of them, ferulic acid, has a positive effect on the cholesterol metabolism. This also appears to be the case for some of the other bacterial metabolic products. »

In a second arm of the study, people were asked to replace one meal with 80g of oatmeal per day, without additional dietary limits, for six weeks. However, this resulted in only modest changes.

Cholesterol can build up on inside artery walls, forming plaques that can narrow blood vessels or block blood flow, triggering a heart attack or stroke.

Prof Simon said: « A short-term oat-based diet at regular intervals could be a well-tolerated way to keep the cholesterol level within the normal range and prevent diabetes.

“As a next step, it can now be clarified whether an intensive oat-based diet repeated every six weeks actually has a permanently preventative effect.”

Oats have historically been linked to metabolic health and German physician Carl von Noorden used them in the early 20th century to treat patients with diabetes.

Prof Simon added: “Today, effective medications are available to treat patients with diabetes. As a result, this method has been almost completely overlooked in recent decades. »