What is oatmeal?

Oatmeal is a type of porridge made from ground or rolled oats.

How does it work?

Oatmeal has various health benefits, including lowering cholesterol levels and reducing the risk of heart disease. It contains beta-glucan, a soluble fiber that forms a gel-like substance in the gut, which can help lower blood cholesterol levels by binding to bile acids and removing them from the body.

What are the active ingredients that are important for its medicinal properties?

The active ingredient in oatmeal that is important for its medicinal properties is beta-glucan.

What forms does it come in?

Oatmeal can be purchased in various forms, including rolled oats, quick oats, instant oats, and steel-cut oats.

When was it first used for medicinal purposes?

Oatmeal has been used for medicinal purposes since ancient times.

What does Oatmeal help with?

Oatmeal is a cooked cereal made from oat grains. People have grown and eaten oats for more than 4,000 years. Greek writers, European herbalists and Ayurvedic texts all list oats as both food and medicine.

For a food, oats are unusually well studied. The strongest evidence sits with LDL cholesterol, thanks to a soluble fiber called beta-glucan. Other uses rest on smaller studies, and one rests on nutrition facts alone.

• High LDL ("bad") cholesterol
  Strong evidence — more clinical trials than almost any other single food, all pointing the same way. In many clinical trials, one to two servings of oats a day lowered LDL cholesterol. The trials used oats giving at least 3g of beta-glucan daily. In lab work, beta-glucan bound bile acids in the gut, so the body pulled cholesterol from the blood to make new bile.
  Evidence grade A · Traditional tier T1
• Blood sugar spikes after meals, and type 2 diabetes
  Good evidence — human trials of regular oat eating, with no trial sizes on file. In human studies, eating oats often improved fasting blood sugar and insulin sensitivity. Lab work shows beta-glucan forms a thick gel in the stomach. That gel slowed how fast carbs were digested, which smoothed the rise in blood sugar after a meal.
  Evidence grade B · Traditional tier T1
• Feeling hungry again soon after breakfast
  Good evidence — trials against calorie-matched breakfast cereals, sizes not on file. In trials, people who ate oatmeal for breakfast ate fewer calories later in the day. The comparison breakfast was a ready-to-eat cereal with the same calories. Researchers credit the protein, beta-glucan and slow-digesting carbs, which delayed hunger for a few hours.
  Evidence grade B · Traditional tier T1
• Constipation and sluggish digestion
  Good evidence — human studies of modest daily oat intake, sizes not on file. In human studies, even small daily amounts of oats improved how often and how easily people passed stool. The people studied had constipation or slow digestion. Oats hold soluble fiber, which softens stool, and insoluble fiber, which adds bulk. That is known fiber science, not a trial of oatmeal itself.
  Evidence grade B · Traditional tier T1
• High blood pressure
  Early evidence — several small trials with modest results. Several small trials found modest drops in both the top and bottom blood pressure numbers. The people in them ate whole-grain oats often. Lab and early human work links oat compounds called avenanthramides to more flexible, less inflamed vessel walls.
  Evidence grade C · Traditional tier T1
• Eczema, itchy skin and dryness
  Early evidence — long human use behind FDA skin-protectant status; no trial sizes on file. Colloidal oatmeal is finely ground oats mixed into water or cream. The FDA recognises it as a skin protectant, and people have used it on sore skin for centuries. In studies of oat avenanthramides, the compounds lowered histamine response and skin inflammation on contact.
  Evidence grade C · Traditional tier T1
• Body-wide inflammation
  Early evidence — human studies of blood markers, not of disease rates. In human studies, oat avenanthramides lowered signs of inflammation, mostly inside blood vessel walls. Eating oats often may lower body-wide inflammation markers, but that is not settled yet. High markers are linked to heart disease and diabetes, though these studies did not track those illnesses.
  Evidence grade C · Traditional tier T1
• An out-of-balance gut microbiome
  Early evidence — human studies that measured bacteria only. In human studies, regular oat eating was linked to measurable shifts in gut bacteria. The shifts favoured Bifidobacterium and Lactobacillus. Lab work shows beta-glucan and resistant starch feed those bacteria, so they act as prebiotics.
  Evidence grade C · Traditional tier T1
• Low energy and morning fatigue
  Not yet tested in people — no human trial on file; nutrient content and general nutrition science only. No human trial of oatmeal for tiredness is on file. Oats are known to be rich in B vitamins, above all thiamine (B1), and they release energy slowly. That is general nutrition science, not a test of oatmeal for low energy.
  Evidence grade insufficient · Traditional tier T1

What Oatmeal has not been shown to do

• No trial on file shows that oatmeal lifts energy or eases fatigue.
• The appetite trials measured calories eaten later that day, not weight loss over time.
• The gut bacteria studies did not show that the bacterial shifts made people feel or function better.
• Oatmeal has not been shown to clear eczema or psoriasis; the work points to soothing itch and dryness on contact.
• The inflammation studies tracked blood markers, not rates of heart disease or diabetes.
• Oats have not been shown to replace cholesterol, blood pressure or diabetes medicine.

How to read this:

Each use above carries its own grade. A means many randomised human trials agree. B means at least one good human trial. C means small or early human work. D means weak or mixed human evidence. Insufficient means no human study at all, only lab, animal or traditional use. This page sets out options and what studies found. It is not advice, and it is not a treatment plan. Talk with your own clinician before you change any medicine.

What can Oatmeal help prevent?

• Cardiovascular disease: consistent daily oat consumption is associated with reduced risk of heart disease in large prospective studies, primarily through LDL reduction and blood pressure support
• Type 2 diabetes: long-term whole grain oat intake is linked to lower risk of developing type 2 diabetes in large cohort studies
• Colorectal cancer: high dietary fiber intake, including from oats, is associated with reduced colorectal cancer risk in multiple large epidemiological studies and meta-analyses

Which foods are rich in it?

Oatmeal is rich in beta-glucan, which is also found in other whole grains such as barley and rye.

What are possible side effects?

Oatmeal is generally well tolerated and does not have any serious side effects. However, some people may experience bloating, gas, or diarrhea if they consume too much fiber.

What’s the recommended daily dose?

The recommended daily dose of oatmeal is ½ to 1 cup per day.

How many days does it take to work?

The effects of oatmeal consumption can vary depending on the individual and the condition being treated. In general, it may take several weeks or months of regular oatmeal consumption to see significant improvements in cholesterol levels or other health outcomes.

What time of day is best to take it?

There is no specific time of day that is best to consume oatmeal.

Is it best to take it with or without food?

Oatmeal can be consumed as a standalone meal or as part of a larger meal. It is generally recommended to consume it with other foods to provide a balanced source of nutrients.