Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate. The effectiveness ratings for OATS are as follows:

Likely effective for…

  • Heart disease. Oat products contain high amounts of fiber. Foods high in soluble fiber can be used as part of a low-fat, low-cholesterol diet to prevent heart disease. Research shows that a person must eat at least 3.6 grams of soluble fiber each day to reduce the risk for heart disease.
  • High cholesterol. Eating oats, oat bran, and other soluble fibers can modestly reduce total and “bad” low-density lipoprotein (LDL) cholesterol when consumed as part of a diet low in saturated fat. For each gram of soluble fiber (beta-glucan) consumed, total cholesterol decreases by about 1.42 mg/dL and LDL by about 1.23 mg/dL. Eating 3-10 grams of soluble fiber can reduce total cholesterol by about 4-14 mg/dL. But there’s a limit. Doses of soluble fiber greater than 10 grams per day don’t seem to increase effectiveness.
  • Eating three bowls of oatmeal (28-gram servings) daily can decrease total cholesterol by about 5 mg/dL. Oat bran products (muffins, oat bran flakes, oat bran Os, etc.) may vary in their ability to lower cholesterol, depending on the total soluble fiber content. Whole oat products might be more effective in lowering LDL and total cholesterol than foods containing oat bran plus beta-glucan soluble fiber.
  • The FDA recommends that approximately 3 grams of soluble fiber be taken daily to lower blood cholesterol levels. However, this recommendation doesn’t match research findings; according to controlled clinical studies, at least 3.6 grams of soluble fiber daily is needed to lower cholesterol.

Possibly effective for…

  • Diabetes. Eating oats and bran for 6 weeks decrease before-meal blood sugar, 24-hour blood sugar, and insulin levels in people with type 2 diabetes. Eating 50-100 grams of oats in place of other carbohydrates reduces after-meal blood sugar in some people. Long-term, eating 100 grams of oats in place of other carbohydrates has the most long-lasting effect on blood glucose. Furthermore, there is some evidence that consuming 50 grams of bran daily, which contains 25 grams of soluble fiber, might be more effective than the standard moderate fiber diet of 24 grams daily recommended by the American Diabetes Association.
  • Stomach cancer. People who eat high-fiber foods, such as oats and bran, seem to have a lower risk of stomach cancer.

Possibly ineffective for…

  • Colon cancer, rectal cancer. People who eat oat bran or oats don’t seem to have a lower risk of colon cancer. Also, eating oat bran fiber isn’t linked with a lower risk of colon tumor recurrence.
  • High blood pressure. Eating oatmeal or cereal doesn’t reduce blood pressure in men with slightly high blood pressure.

Insufficient evidence to rate effectiveness for…

  • Memory and thinking skills (cognitive function). Early research shows that taking a specific wild green-oats extract (Neuravena) might improve the speed of mental performance in healthy adults.
  • Dry skin. Using lotion containing colloidal oat extract seems to improve dry skin.
  • Changes in how fat is distributed in the body in people taking HIV medications. Eating a high-fiber diet, including oats, with adequate energy and protein might prevent fat accumulation in people with HIV. A one-gram increase in total dietary fiber may decrease the risk of fat accumulation by 7%.
  • Itching. Early research shows that applying lotion-containing oats reduces skin itching in people with kidney disease. The lotion seems to work as well as taking the antihistamine hydroxyzine 10 mg.
  • Anxiety.
  • Loss of bladder control (urinary incontinence).
  • Constipation.
  • Diarrhea.
  • Diverticulosis.
  • Gout.
  • Inflammatory bowel disease.
  • A long-term disorder of the large intestines that causes stomach pain (irritable bowel syndrome or IBS).
  • Rheumatoid arthritis (RA).
  • Osteoarthritis.
  • Fatigue.
  • Chronic fatigue syndrome (CFS).
  • Withdrawal from heroin, morphine, and other opioid drugs.
  • Gallbladder disease.
  • Flu (influenza).
  • Cough.
  • Frostbite.
  • Wound healing.
  • Rough, scaly skin on the scalp and face (seborrheic dermatitis).
  • Acne.
  • Burns.
  • Eczema (atopic dermatitis).
  • Other conditions.
More evidence is needed to rate oats for these uses.

Side Effects of Oats

  • When taken by mouth: Oat bran and whole oats are LIKELY SAFE for most people when used in the amount found in foods. They can cause intestinal gas and bloating. To minimize side effects, start with a low dose and increase slowly to the desired amount. Your body will get used to oat bran and the side effects will likely go away.
  • When applied to the skin: Lotion-containing oat extract is POSSIBLY SAFE to use on the skin. Putting products on the skin can cause some people to have a rash.

Warnings & Precautions

  • Pregnancy and breast-feeding: Oat bran and whole oats are LIKELY SAFE when ingested by pregnant and breast-feeding women in the amounts found in foods.
  • Difficulty swallowing food or chewing problems: If you have swallowing problems or if you have trouble chewing, it’s best to avoid eating oats. Poorly chewed oats can cause blockage of the intestine.
  • Disorders of the digestive tract including the esophagus, stomach, and intestines: Avoid eating oat products. Digestive problems that could extend the length of time it takes for your food to be digested could allow oats to block your intestine.

Dosage Of Oats

The following doses have been studied in scientific research:


  • For heart disease: Products that contain 3.6 grams of beta-glucan (soluble fiber) daily, as part of a low-fat, low-cholesterol diet. One-half cup (40 grams) of Quaker oatmeal contains 2 grams of beta-glucan; one cup (30 grams) of Cheerios contains one gram of beta-glucan.
  • For high cholesterol: 56-150 grams of whole oat products such as bran or oatmeal, containing 3.6-10 grams of beta-glucan (soluble fiber) daily as part of a low-fat diet. One-half cup (40 grams) of Quaker oatmeal contains 2 grams of beta-glucan; one cup (30 grams) of Cheerios contains one gram of beta-glucan.
  • For lowering blood sugar levels in patients with type 2 diabetes: High fiber foods such as whole oat products containing up to 25 grams of soluble fiber are used daily. 38 grams of bran or 75 grams of dry oatmeal contains about 3 grams of beta-glucan.


Consult your doctor or pharmacist.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.