Celiac is a politically unbiased autoimmune disease. Seems both Chelsea Clinton and Elizabeth Hasselbeck have it and can't stomach the same things. (Who would have ever suspected!) Gluten-containing foods -- wheat, rye, barley, some oats and many prepared foods -- are off their menu.

They're not alone: Celiac is 40 times more common than docs used to think, possibly affecting as many as one in 133 in North America. And if your parents, sibs or kids have celiac, there's a one in 22 chance you do, too.

Celiac is woefully underdiagnosed. Millions are at risk for its complications, including GERD and osteoporosis (in adults), and anemia, abdominal pain and growth deficiencies (in children), not to mention epilepsy and irregular heartbeat (atrial fibrillation).

Celiac disease damages tiny villi lining the small intestines, which normally shuttle nutrients from food into the bloodstream. When they can't, you get nutritional deficiencies, diarrhea, cramping, vomiting, weight loss, even skin rashes.

If you suspect gluten is causing your digestive distress:

1. Talk to your doc about a blood test for gluten auto-antibodies (lgA & IgG, lgA EMA, and tTG IgA). Positive results? A biopsy will confirm the diagnosis.

2. If diagnosed, eliminate gluten from your diet (and avoid other gluten-hiding substances, even makeup).

3. Get folate levels tested: Supplements may be essential to healing.

4. Eat lots of whole grains (without gluten): amaranth, buckwheat, chia, corn, millet, quinoa, rice, sorghum and wild rice.

You'll feel better with your gluten-free advantage, and you'll make your RealAge much younger.

Mehmet Oz, M.D. is host of “The Dr. Oz Show,” and Mike Roizen, M.D. is Chief Medical Officer at the Cleveland Clinic Wellness Institute. For more information go to www.RealAge.com.