Young Ju, Ph.D.

The term “feeling your oats” was derived from the frisky and active way horses responded to having oats in their diet.  Research is showing that there may be real health benefits to oats in the human diet as well.

Oats

Oats are a good source of high-quality protein, carbohydrate, and fat. Besides this macronutrient value, oats contain high amounts of a soluble dietary fiber called beta-glucan. Oats (as well as barley) are particularly rich in beta-glucan, but we can also get it from bacteria, yeast, algae, and mushrooms. Beta-glucan is the key ingredient in oats that works to lower cholesterol. (For more information on cholesterol, see the January newsletter.)

In the U.S., the average person consumes ~5 pounds of oat products per year (1). Usually, oat consumption is higher in January than other months which is likely affected by cold weather. In the U.S. most oats are minimally processed, either steamed and flattened to produce rolled oats and sold as regular oats, quick oats, instant oats, or “old-fashioned” oats. The more oats are processed, the quicker they cook, although steaming and flattening are considered minimal food processing which does not alter the nutritional composition of oats.

In 1997, the U.S. Food and Drug Administration (FDA) approved a health claim that beta-glucan from oatmeal, oat bran, and whole oat flour reduced the risk of heart disease (“3 g or more per day of beta-glucan soluble fiber from whole oats, oatmeal, oat bran, and whole oat flour”). In 2002, this approval was amended to include oatrim (2). 

• Oatmeal: Rolled oats, also known as oatmeal, is produced from 100% dehulled, clean oat groats by steaming, cutting, rolling, and flaking, and contains at least 4% beta-glucan.

• Oat Bran: Oat bran is produced by grinding clean oat groats or rolled oats.  It contains at least 5.5%  beta-glucan.

• Whole Oat Flour: Whole oat flour is produced from 100% dehulled, clean oat groats by steaming and grinding and contains at least 4% beta-glucan.

• Oatrim: Oatrim is a fraction of digestive-enzyme-treated oat bran or whole oat flour and is made up of 5-10% beta-glucan. Oatrim is used to replace fat and increase soluble-fiber content in many foods, including processed meats, dairy, and bakery goods. 

Cholesterol-Lowering Effects of Oat Beta-Glucan

Since the FDA’s acceptance in 1997, research evidence continues to support a strong relationship between oat beta-glucan consumption and lowering cholesterol levels and/or risk of heart disease. Human studies conducted between 1997 and 2021 have shown that oats, oat products, and oat beta-glucan lowered total cholesterol and LDL-c (bad cholesterol) levels but had no impact on HDL-c (good cholesterol) or triglycerides (3, 4).

Oat beta-glucan dissolves in water forming a viscous (or gel-like) solution in the gut.  Thus it prevents reabsorption of cholesterol and LDL-cholesterol (bad cholesterol) from the gut to the bloodstream.

Research has also shown that less-processed and whole-oat-based products are more effective in lowering cholesterol compared to highly processed oat products.  For example, 1 1/2 cups of oatmeal has ~3 grams of beta-glucan, while a processed packet of instant oatmeal has only 1 gram.

Oat Beta-Glucan as a Food Additive

Due to its water-holding, fat-binding, and gelling properties, beta-glucan is also widely used as a food additive in diverse food categories including processed meats, dressing, frozen doughs and desserts, noodles, yogurts, fermented milks, and plant-based products, etc.

Cooking methods, food forms (matrices), and storage conditions affect the amount of beta-glucan and/or its cholesterol-lowering capability (5).  For example, beta-glucan levels are preserved in porridge and pancakes; however, they degrade in bread, pasteurized juices, and pasta.  Several studies that tested oat beta-glucan in bread and/or muffins did not observe significant reduction in total cholesterol and LDL-c levels.  Studies also found that frozen storage and freeze-thaw cycles reduced up to 50% of the beta-glucan in oat or oat bran muffins.

Oat Beta-Glucan Dietary Supplements

Beta-glucan extracted from oats, mushrooms, and yeast is also available in dietary supplements. Beta-glucan contents in these supplements range from 0.25 – 1 g per serving size. 

A beta-glucan supplement has the potential to slow the absorption of drugs if taken at the same time.  In general, other medications should be taken at least one hour before or two hours after a beta-glucan supplement.

Feel Your Oats

Overall, research supports that eating oats can improve your lipid profile and reduce your risk of heart disease.  Thus, one easy and effective way to lower cholesterol levels is having a bowl of oatmeal every morning. Oats are easily tolerated by most people and provide long-lasting energy.  You may even find that increasing your consumption of oats as a snack or for breakfast results in a more energetic and active you on the tennis court.

REFERENCES

1. Statista. Per capita consumption of oat products in the United States from 2000 to 2019. https://www.statista.com/statistics/184204/per-capita-consumption-of-oat-products-in-the-us-since-2000/

2. U.S. Food & Drug Administration.  Code of Federal Regulations Title 21   https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=101.81

3. Joyce, S.A., Kamil, A., Fleige, L., Gahan, C.G. M. The cholesterol-lowering effect of oats and oat beta glucan: modes of action and potential role of bile acids and the microbiome. 2019 Front Nutrition 6: 171.

4. Paudel, D., Dhungana, B., Caffe, M., Krishnan, P. A review of health-beneficial properties of oats. 2021. Foods 10:2591

5. Henrion, M., Francey, C., Le, KA., Lamothe, L. Cereal B-glucans: The impact of processing and how it affects physiological responses. 2019. Nutrients 11(8):1729.

People with high cholesterol and at risk of high cholesterol should talk to their healthcare providers about cholesterol management strategies.   This information is provided for your reference and you use at your own risk; you should rely on your medical professional for medical advice.