Oatmeal: Heart healthy. . . or Not?

by William Davis, M.D. Health Professional

You've heard the message: Oatmeal reduces cholesterol. You'll find the message on oatmeal containers, oat-containing breakfast cereals, and anything else made with oats or oatmeal.

This is because oatmeal producers and food manufacturers have obtained permission from the FDA to use a cholesterol-reducing claim on oat-containing products. The American Heart Association also provides an (paid) endorsement of Quaker Oats.

Ask someone whether they ate a healthy breakfast and the answer will often be, "Sure. I had oatmeal."

Is this true? Is oatmeal heart healthy because it reduces LDL cholesterol?

I don't think so. Sure, oatmeal can reduce LDL cholesterol modestly. But try this: Have a serving of slow-cooked (e.g., steel-cut, Irish, etc.) oatmeal. Most people will consume oatmeal with skim or 1% milk and some dried or fresh fruit. Wait an hour, then check your blood sugar.

If you are not diabetic and have a fasting blood sugar in the "normal" range (<100 mg/dl), you will typically have a 1-hour blood glucose of 150-180 mg/dl-that's very high. Not everybody will show this response, but a frightening majority will. Try it with "quick" or instant oatmeal and the blood sugar effect can be even worse.

If you have mildly increased fasting blood sugars between 100 and 126 mg/dl, after-oatmeal blood sugars will easily exceed 180 mg/dl. If you have diabetes, hold onto your hat because, even if you take medications, blood sugar one hour after oatmeal will usually be between 200 and 300 mg/dl.

Oatmeal is converted rapidly to sugar--and a lot of it. Even if you repeated the experiment with no dried or fresh fruit, you will still witness high blood sugars. Pile on raisins, dried cranberries, or brown sugar, and blood sugars will climb even higher.

Blood sugars this high, experienced repetitively, will damage the delicate insulin-producing beta cells of the pancreas (glucose toxicity). This damage is irreversible, leading you down the path to diabetes. High blood sugars also glycate proteins of the eyes and vascular walls, i.e., bind to proteins and modifying their structure. The blood glucose effects of oatmeal really don't differ much from a large Snickers
® bar or bowl of jelly beans.

If you are like most people, you too will show high blood sugars after oatmeal. It's easy to find out...check your blood sugar one hour after eating.

Better breakfast choices: eggs, ground flaxseed as a hot cereal, cheese (the one dairy product that does not excessively trigger insulin), raw nuts, salads, leftovers from last evening's dinner.

William Davis, M.D.
Meet Our Writer
William Davis, M.D.

William R. Davis is a Milwaukee-based American cardiologist and author. He wrote for HealthCentral as a health professional for Heart Health and High Cholesterol.