[wgjordan]

It's well known that an oatmeal diet lowers cholesterol (the article itself cites a 1907 'oat cure' in its intro). The new finding here is insight into the exact mechanism- a short-term, high-dose oatmeal diet (300g/day for two days) had significantly greater LDL-lowering effect than a medium-term, moderate-dose oatmeal diet (80g/day for six weeks), and they associated the difference with increases in several plasma phenolic compounds triggered by specific changes in the gut microbiome.

[strken]

I'm left wondering what happens if you feed people 300g/day of barley, shredded wheat, brown rice, or any other wholegrain. For that matter, what happens if you do the same thing with legumes?

The experiment halved energy intake at minimum and still provided 30+ grams of fibre then kept doing it until the gut emptied, which I reckon most people would expect to nuke and replace the gut microbiome, but did oatmeal have any specific advantage?

[JeremyNT]

Yeah this is a really wild experiment.

Their hypothesis for the mechanism is "gut bacteria" but these people in the study all had a trifecta of "high" body weight (overweight? obese? not specified in this article), high blood pressure, and hyperlipidemia.

So we've got some unhealthy people, we cut their calories to less than half, we jack their fiber way up (most likely - we don't know their baseline diet but with those biomarkers we can make some educated guesses), we restrict the timing of when they eat and remove all junk food.

So is this oatmeal specifically? Fiber? Calorie deficit? Meal timing effects? Removal of processed food for two days?

The idea that you can "shock" your body to better biomarkers like this and have it last over a month is extremely cool, but I wonder how they can be certain that this is some oatmeal thing versus a general "eat way less and limit yourself to a food that is high in fiber" thing.

The low protein here is a problem when in a calorie deficit, for example, because if you don't have enough protein you're likely to lose weight as muscle mass rather than fat. If you could do the same technique with legumes your protein would be way better.

[js2]

> people in the study all had a trifecta

It's an intervention for people with metabolic syndrome, characterized specifically by those traits. Quoting the first sentence of the paper:

"Metabolic syndrome (MetS), characterized by the co-occurrence of central obesity, dyslipidemia, elevated blood pressure (BP), and dysglycemia, ..."

https://www.nature.com/articles/s41467-026-68303-9

[michaelbrave]

I don't think it's the fiber.

I did a similar unscientific experiment in the past where I did a juice fast for two weeks and had bloodwork done before and after (similar bodytype, unhealthy, overweight, high blood sugars, high cholesterol etc). Basically the doctor was shocked how all my numbers became the same as someone really healthy during the fast. So I think the lack of junk and calorie restriction is doing more than the fiber.

[js2]

The paper does a better job explaining why oats were chosen:

> Oats offer an interesting and promising approach for treating MetS due to their unique composition characterized by a high fiber content, especially β-glucan, essential minerals and vitamins, and various bioactive substances, including phenols which exert antioxidant and anti-inflammatory effects that may improve metabolic function. Furthermore, oats are an accessible and sustainable food item.

https://www.nature.com/articles/s41467-026-68303-9

[x0x0]

300g is a lot of oatmeal.

I eat Bob's Red Mill steel cut oats for breakfast every day; 1/2c dry is about 88g. That's a pretty decent meal. 3.5x that is probably most of what you eat that day.

[wgjordan]

Yeah, the article showed that the high-dose intervention (modeled after von Noorden's famous century-old 'oat cure') is most effective. A large bowl of oatmeal (100g) all 3 meals for 2 days, 6 large bowls total.

6 weeks of 'oatmeal for breakfast every day' was less effective than 2 days of 'stuff yourself with oatmeal'.

[Marsymars]

It's quite a bit of volume, but it's "only" about 1000 Calories if it doesn't have any oils/sugar added.

I'd guess the easiest way to get it down would be to just blend the oats into water without cooking so you have something that you can just drink like water.

[briHass]

Wasn't that basically what Soylent was? With a ground up multivitamin and some oil drizzled in?

[brador]

And this is the real reason.

The oatmeal put them on a crash diet of 1000 calories a day. And filled them so they didn’t reach for non reported snacks.

[FrancisMoodie]

They had a control group who also went on a reduced calorie deficit but without oats and found that the oats eating group had a much higher decrease of cholesterol, it's in the article.

[raydev]

Oats group saw a decrease of 10% but the number for the control group is not given.

[_flux]

Two-day crash diet can reduce LDL levels for 6 weeks?

[red-iron-pine]

i mean we talkin cooked or uncooked?

88g dry may get much heavier after adding 3/4 cups water

[dredmorbius]

3/4 cup is about 315 ml, or another 315 g, for just over 400g cooked weight. The linked article does not make clear whether or not the 300g is dry or cooked weight.

The original paper describes two protocols, short-term and long-term (2-day and 6-week respectively) of 100g dry oats and 80g dry oats prepared for each meal. That's a generous but not outrageous serving size, and the former comes out to 300g oats per day over three meals.

<https://www.nature.com/articles/s41467-026-68303-9#Sec15>

[x0x0]

88g dry; I add 3/4 cup milk and 1/2 c water.

[mytailorisrich]

Part of the effect is caused by the heavy calorie restriction as the control group also saw LDL lowering but less.

Indeed they suggest that the difference may be due to changes in gut microbiome caused by oatmeal.

[reedf1]

What does the practical implementation of this look like? One 'oatmeal-day' a week ? Two?

[n4r9]

Probably two days a month would suffice, given how long the beneficial effects are reported to last.