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The Little-Known Food Intolerance That Could Be Harming Your Health (Hint: It's Not Gluten)

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November 6, 2015

William Cole, DC, a functional medicine practitioner, is an expert at identifying the underlying factors of chronic conditions. Join Dr. Cole for an exclusive webinar on May 24, 2016, and learn how to uncover your food intolerances, heal your gut, and feel your best again. Register now to snag your free spot, and in the meantime, check out his mindbodygreen course,The Elimination Diet: A 60-Day Protocol to Uncover Food Intolerances, Heal the Gut, and Feel Amazing.

Gluten has become a household name, and not for good reasons. The protein that's found in many grains, such as wheat, rye and barley, is considered to be a triggering factor for many health problems affecting the brain, thyroid and skin, as well as autoimmune diseases.

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Studies have also linked gluten intolerance to digestive problems. Irritable Bowel Syndrome (IBS) alone affects as many as 15% of Americans. It can come with debilitating stomach pain and times of diarrhea or constipation.

IBS often goes beyond bathroom problems, though. Because of the gut-brain connection, as many as 90% of people with IBS also have psychiatric disorders, including panic disorder, generalized anxiety disorder and major depression.

Millions more Americans live with undiagnosed bouts of bloating, constipation and diarrhea and consider it normal.

But what happens when going gluten-free, as is often recommended, doesn't solve your digestive problems? What happens when it's not gluten's fault?

In my practice, I find that a major culprit in many of my patients is an intolerance to a class of foods known as FODMAPS.

Around 75% of people struggling with IBS symptoms improve with a low-FODMAP diet.


This funny sounding acronym stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols. In other words: fermentable sugars. These short-chain sugars are not fully digested in your gut and can be excessively fermented by your gut bacteria.

This fermentation releases hydrogen gas that causes distension of the intestines — which can cause major IBS symptoms like pain, gas, bloating, constipation and diarrhea.

The good news is that research suggests that around 75% of people struggling with IBS symptoms will improve with a low-FODMAP diet. I find that people struggling with acid reflux or GERD can also benefit from a low-FODMAP approach to eating.

Even if you simply have some bloating, this can be an effective tool to manage your gastrointestinal symptoms.

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What Are High-FODMAP Foods To Avoid?

Most of the high-FODMAP foods are actually healthy, real foods. But even when it comes to natural foods, what works for one person may not be right for everyone. Here are the foods that should be avoided or severely limited on a low-FODMAP diet:


Artichokes, asparagus, beetroot, celery, garlic, onions, leek bulb, legumes, pulses, Savoy cabbage, sugar snap peas, sweet corn


Apples, mango, nectarines, peaches, pears, plums, watermelon


Milk, cream, custard, ice cream, soft cheeses, yogurt


Rye, wheat-containing breads, cereals, crackers, pasta


Cashews, pistachios

What should I do now?

If you're struggling with gut problems like IBS, here are some practical ways to start taking action:

1. Try out a low-FODMAP diet.

Focus on eating the vegetables, fruits and clean meats that are not on the high-FODMAP list, and see if your symptoms improve. The good news is that with time, many people can slowly start increasing the high-FODMAP foods as they heal their gut and decrease their FODMAP intolerance.

2. Consider comprehensive GI labs.

Lactulose breath test: FODMAP intolerance is linked to SIBO, or small intestinal bacterial overgrowth. This lab measures the gases, methane and hydrogen, released by the bacterial overgrowth.

Microbiome stool test: IBS is associated with an increase in pathogenic (bad) bacteria. By measuring the levels of good and bad bacteria, this will help you understand your unique microbiome issues.

Leaky gut blood lab: By measuring the antibodies to occludin and zonulin, the proteins that control gut lining permeability, we can rule in leaky gut syndrome, which is common with IBS.

3. Consider food intolerance labs.

If you're having an intolerance to FODMAPS, other underlying food immune reactivities should be checked out as well. Blood tests for these intolerances can be helpful for people who are having gastrointestinal symptoms.

4. Manage stress.

Ever wondered why people often have gut problems when they are nervous or stressed? It's the gut-brain axis at work. Research suggests that stress can lead to an overgrowth of certain types of bacteria and decrease the diversity in the microbiome.

My favorite stress reducers: yoga, mindfulness meditation, tai chi, and spending time in nature.

5. Try taking probiotics.

A combination of Bifidobacteria, Enterococcus and Lactobacillus has been shown to be effective in improving irritable bowel syndrome.

6. Consider functional medicine.

In functional medicine, we realize that everyone is different. Healing the gut is a journey and troubleshooting what works for you can be overwhelming. Consider a free webcam or phone health evaluation to get a functional medicine perspective on gut health.

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William Cole, IFMCP, DNM, D.C.
William Cole, IFMCP, DNM, D.C.

Will Cole, IFMCP, DNM, D.C., is a leading functional medicine expert who consults people around the world via webcam and locally in Pittsburgh. He has holds a level 2 Doctor of Natural Medicine (DNM) certification. Named one of the top 50 functional and integrative doctors in the nation, Cole specializes in clinically investigating underlying factors of chronic disease and customizing a functional medicine approach for thyroid issues, autoimmune conditions, hormonal imbalances, digestive disorders, and brain problems. He is also the host of the popular The Art Of Being Well podcast and bestselling author of Ketotarian, The Inflammation Spectrum, and the New York Times bestseller Intuitive Fasting.

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