Oats
Oats and oat beta-glucan are studied for cholesterol, glycemic, and gut-related outcomes.
Overview
What are oats?
Oats are a type of cereal grain that contain high amounts of the soluble fiber known as beta-glucan which helps to support cardiovascular health. Oats also provide unique antioxidants called avenanthramides and other polyphenols that reduce inflammation and oxidative stress. They are rich in vitamins B1 (thiamine), B5, and folate, as well as minerals like zinc, iron, copper, phosphorus, and magnesium.
Dosage
A typical dose of oats per day contains at least 3-4 grams of soluble fiber (around half a cup).
Effect graph
Effect heatmap
SupplementDEX Database
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Database Snapshot
Most oats research is concentrated in a handful of conditions.
- Coronary heart disease accounts for 14 of 40 studies (35%).
- Diabetes accounts for 11 of 40 studies (28%).
- Dyslipidemia accounts for 10 of 40 studies (25%).
- Sparse coverage remains for Blood sugar control, Stomach cancer.
Dietary Sources
Top dietary sources
Food sources
Oats are commonly consumed as oatmeal (porridge) and are also used in granola, muesli, bread, and baked goods.
Sources include Oat bran, Oat flour, Oatmeal, Rolled oats, Steel-cut oats, and Whole oat groats.
Safety
Oats are likely safe when consumed in normal food amounts.
Frequently Asked Questions
References
Sources31 references
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SupplementDEX Database · Coronary heart disease
14 references1.SupplementDEX Database: Coronary heart disease — The Prebiotic Effects of Oats on Blood Lipids, Gut Microbiota, and Short-Chain Fatty Acids in Mildly Hypercholesterolemic Subjects Compared With Rice: A Randomized, Controlled Trial2021
In 210 mildly hypercholesterolemic Chinese adults, 80 g/day oats for 45 days reduced total and non-HDL cholesterol more than rice and shifted gut microbiota toward taxa linked to lower LDL.
2.SupplementDEX Database: Coronary heart disease — Oats and soy in lipid-lowering diets for women with hypercholesterolemia: is there synergy?2001
In 127 postmenopausal women with hypercholesterolemia, oats plus soy did not show clear synergy beyond Step I diet effects on total or LDL cholesterol over 6 weeks.
3.SupplementDEX Database: Coronary heart disease — Dietary fiber, weight gain, and cardiovascular disease risk factors in young adults1999
In 2,909 CARDIA participants followed 10 years, higher dietary fiber intake was linearly associated with lower body weight, waist-to-hip ratio, and fasting insulin in both black and white young adults.
4.SupplementDEX Database: Coronary heart disease — Cholesterol-lowering effects of dietary fiber: a meta-analysis1999
A meta-analysis of 67 controlled trials found 2–10 g/day soluble fiber (pectin, oat bran, guar, psyllium) significantly lowered total cholesterol (~0.045 mmol/L per g) and LDL cholesterol (~0.057 mmol/L per g).
5.SupplementDEX Database: Coronary heart disease — Fiber, lipids, and coronary heart disease. A statement for healthcare professionals from the Nutrition Committee, American Heart Association1997
An American Heart Association scientific statement summarized evidence that dietary fiber, particularly soluble fiber, improves lipid profiles and may lower coronary heart disease risk.
6.SupplementDEX Database: Coronary heart disease — Vegetable, fruit, and cereal fiber intake and risk of coronary heart disease among men1996
In 43,757 US male health professionals followed 6 years, men in the highest fiber quintile (28.9 g/day) had 41% lower fatal CHD risk than those in the lowest quartile (12.4 g/day).
7.SupplementDEX Database: Coronary heart disease — Intake of dietary fiber and risk of coronary heart disease in a cohort of Finnish men. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study1996
In 21,930 Finnish smoking men followed 6.1 years, highest total fiber intake (median 34.8 g/day) was associated with 31% lower coronary death risk versus the lowest quintile (16.1 g/day), independent of other risk factors.
8.SupplementDEX Database: Coronary heart disease — Oats and buckwheat intakes and cardiovascular disease risk factors in an ethnic minority of China1995
In 850 Yi adults in China, 100 g/day oats intake was associated with lower BMI, blood pressure, and HDL cholesterol; 100 g/day buckwheat with lower total and LDL cholesterol.
9.SupplementDEX Database: Coronary heart disease — Oat beta-glucan reduces blood cholesterol concentration in hypercholesterolemic subjects1994
In 19 hypercholesterolemic adults, 2.9 g/day purified oat beta-glucan for 4 weeks reduced fasting total cholesterol and LDL cholesterol by 9% each versus baseline; levels returned after stopping supplementation.
10.SupplementDEX Database: Coronary heart disease — Oat products and lipid lowering. A meta-analysis1992
A meta-analysis of 10 oat trials found blood total cholesterol fell by 0.13 mmol/L (~5.9 mg/dL) with oat products; larger reductions occurred when baseline cholesterol was ≥5.9 mmol/L and soluble fiber dose was ≥3 g/day.
11.SupplementDEX Database: Coronary heart disease — The hypocholesterolemic effects of beta-glucan in oatmeal and oat bran. A dose-controlled study1991
In 156 hypercholesterolemic adults, 6 weeks of 56–84 g/day oatmeal or oat bran reduced LDL cholesterol by 10–16% versus farina control; 56 g oat bran lowered LDL more than 56 g oatmeal, supporting a beta-glucan dose effect.
12.SupplementDEX Database: Coronary heart disease — Lipid responses of hypercholesterolemic men to oat-bran and wheat-bran intake1991
In 20 hypercholesterolemic men on a metabolic ward, 21 days of oat bran lowered total cholesterol by 12.8% and LDL by 12.1%, while matched wheat bran had no significant lipid effect.
13.SupplementDEX Database: Coronary heart disease — Dietary fiber and reduced ischemic heart disease mortality rates in men and women: a 12-year prospective study1987
In 859 southern Californians aged 50–79 followed 12 years, dietary fiber ≥16 g/day was associated with 67% lower ischemic heart disease mortality in men and 63% lower in women versus lower intake.
14.SupplementDEX Database: Coronary heart disease — Serum lipid response to oat product intake with a fat-modified diet1986
In 208 adults on a fat-modified diet, adding 60 g/day oat bran or oatmeal for 6 weeks further lowered mean serum cholesterol by 5.6–6.5 mg/dL beyond diet alone (p<0.05).
SupplementDEX Database · Dyslipidemia
3 references15.SupplementDEX Database: Dyslipidemia — The separate effects of whole oats and isolated beta-glucan on lipid profile: A systematic review and meta-analysis of randomized controlled trials2023
A meta-analysis of 28 RCTs (1,494 subjects) found both whole oats and isolated beta-glucan significantly improved total cholesterol and LDL versus control in hyperlipidemic adults.
16.SupplementDEX Database: Dyslipidemia — Improvement in cardiometabolic risk markers following an oatmeal diet is associated with gut microbiota in mildly hypercholesterolemic individuals2022
In mildly hypercholesterolemic adults, 45 days of oatmeal lowered total cholesterol by 8.6% and LDL by 13% and was associated with favorable gut microbiota and SCFA shifts.
17.SupplementDEX Database: Dyslipidemia — Cholesterol-lowering effect of beta-glucan from oat bran in mildly hypercholesterolemic subjects may decrease when beta-glucan is incorporated into bread and cookies2003
In mildly hypercholesterolemic subjects, 5 g/day beta-glucan in orange juice lowered LDL by 0.26 mmol/L (6.7%) over 2 weeks, but beta-glucan in bread and cookies for 3 weeks did not significantly change LDL.
SupplementDEX Database · Blood sugar control
1 reference18.SupplementDEX Database: Blood sugar control — Oat beta-glucans consumed at breakfast improve glucose tolerance acutely and after a subsequent lunch - a randomized dose-response study in healthy young adults2025
In 19 healthy adults, 2–4 g oat beta-glucan with 30 g available carbohydrate reduced postprandial glucose peak and improved glycemia after a subsequent lunch vs reference drink.
SupplementDEX Database · Cardiovascular health
2 references19.SupplementDEX Database: Cardiovascular health — Comparison of Low-Gluten Diets Rich in Oats or Rice-A 6-Week Randomized Clinical Trial With Metabolically Challenged Volunteers2025
In 69 volunteers on low-gluten diets for 6 weeks, oats lowered LDL-C more than rice and improved stool form and bowel movement frequency vs rice.
20.SupplementDEX Database: Cardiovascular health — Effect of oat supplementation interventions on cardiovascular disease risk markers: a systematic review and meta-analysis of randomized controlled trials2022
A meta-analysis of 59 oat intervention RCTs found oat supplementation lowered total cholesterol by 0.42 mmol/L, LDL by 0.29 mmol/L, weight by 0.94 kg, and waist circumference by 1.06 cm.
SupplementDEX Database · Diabetes
10 references21.SupplementDEX Database: Diabetes — A Systematic Review and Meta-Analysis of Randomized Controlled Trials on the Effects of Oats and Oat Processing on Postprandial Blood Glucose and Insulin Responses2021
A meta-analysis found intact oat kernels and thick oat flakes significantly lowered postprandial glucose and insulin vs refined grains; thin/instant flakes showed weaker effects.
22.SupplementDEX Database: Diabetes — The effect of oat bran consumption on gestational diabetes: a randomized controlled clinical trial2021
In 112 women with gestational diabetes, adding 30 g/day oat bran to a GDM diet for 4 weeks lowered fasting and 2-hour postprandial glucose vs diet alone.
23.SupplementDEX Database: Diabetes — The effect of beta-glucan supplementation on glycemic control and variability in adolescents with type 1 diabetes mellitus2020
In 30 adolescents with type 1 diabetes, 6 g/day oat beta-glucan for 1 week lowered mean, premeal/postmeal, and peak glucose and reduced glycemic variability (SD, CV, LBGI, CONGA) versus lower doses.
24.SupplementDEX Database: Diabetes — Higher Whole-Grain Intake Is Associated with Lower Risk of Type 2 Diabetes among Middle-Aged Men and Women: The Danish Diet, Cancer, and Health Cohort2018
In 55,465 Danish adults, each 16 g/day whole-grain increment was associated with 11% (men) and 7% (women) lower type 2 diabetes risk; oats contributed to whole-grain intake.
25.SupplementDEX Database: Diabetes — Short- and Long-Term Effects of Wholegrain Oat Intake on Weight Management and Glucolipid Metabolism in Overweight Type-2 Diabetics: A Randomized Control Trial2016
In 298 overweight type 2 diabetic adults, 30-day centralized oat intake (50–100 g/day) improved fasting and postprandial glucose and lipids vs control diet in a randomized trial.
26.SupplementDEX Database: Diabetes — The Metabolic Effects of Oats Intake in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis2015
A meta-analysis found oats intake in type 2 diabetes lowered HbA1c by 0.42%, fasting glucose by 0.39 mmol/L, total cholesterol by 0.49 mmol/L, and LDL by 0.29 mmol/L.
27.SupplementDEX Database: Diabetes — Beneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitus2000
In 13 type 2 diabetic patients, a high-fiber diet (50 g/day, half soluble) for 6 weeks lowered preprandial glucose by 13 mg/dL vs a moderate-fiber ADA diet.
28.SupplementDEX Database: Diabetes — The role of viscous soluble fiber in the metabolic control of diabetes. A review with special emphasis on cereals rich in beta-glucan1997
A review concluded beta-glucan–rich oats and barley (≥3 g/day beta-glucan, ~10% in food) can reduce glycemic peaks by ~50% and lower LDL in diabetic individuals.
29.SupplementDEX Database: Diabetes — Oat bran concentrate bread products improve long-term control of diabetes: a pilot study1996
In 8 men with NIDDM, oat bran concentrate bread providing 9 g/day soluble fiber for 12 weeks improved long-term glycemic control and insulin profiles vs white bread periods.
30.SupplementDEX Database: Diabetes — High beta-glucan oat bran and oat gum reduce postprandial blood glucose and insulin in subjects with and without type 2 diabetes1994
In subjects with and without type 2 diabetes, oat bran and oat gum meals lowered postprandial glucose and insulin excursions vs wheat farina control.
SupplementDEX Database · Stomach cancer
1 reference31.SupplementDEX Database: Stomach cancer — Inverse association between intake of cereal fiber and risk of gastric cardia cancer2001
In a case-control study, highest quartile of cereal fiber intake was associated with 70% lower odds of gastric cardia adenocarcinoma vs lowest quartile (OR 0.3).