The Way to BE

Top 5 Foods That Damage Your Digestion

For every one human cell, there are 10 bacteria. Many of these bacteria live inside the intestines—mostly the large intestine. They are especially fond of the gel-like mucus that your intestinal cells secrete.

The proteins in gluten are pro-inflammatory. They destroy the gut lining and make it “leaky.”

White blood cells are members of your defense team. Besides bacteria and yeast, you will find specialized white blood cells in the mucosal lining of your digestive tract. Even more of your immune system lies just beneath the intestinal wall, in a mass of lymph tissue.

At any one time:

    Drinking regular or diet soda can disrupt your delicate inner ecosystem. Both natural and artificial sweeteners trigger an inflammatory response and negatively affect bacteria and yeast in the digestive tract.

  • Your immune system communicates with the bacteria and yeast in your gut.
  • The bacteria and yeast communicate with your immune system.
  • Mucosal intestinal cells can send signals of distress or balance to other mucosal tissue (for example, within the lungs or birth canal).
  • Your immune system and inflammatory signaling speak to the rest of your body.

This is your inner ecosystem. The yeast and bacteria that help to create your inner ecosystem evolve with you. In fact, they are so important to your health, the balance of your immune system, and your survival that scientists have coined your inner ecosystem the “forgotten organ.” (1)

Like any organ in the human body, your inner ecosystem is susceptible to injury and disease.

And unfortunately, stress from the environment or even diet can easily damage this “organ.” Signs to look out for include the common hallmarks of poor digestion, like:

  • Heartburn
  • Constipation or diarrhea
  • Intestinal pain or cramping
  • Gas

The reality is that poor digestion can be silent. In other words, you may think that your digestive tract is healthy—meanwhile, you have unexplained migraines, anxiety, depression, joint pain, eczema, allergies, or acne.

One of the best ways to take care of your inner ecosystem is to know which favorite foods (or drinks) can stir up the most trouble.

Top 5 Foods to Avoid

1. Soda Pop: Whether your soda is naturally or artificially sweet, studies agree that the sugar, high-fructose corn syrup, or synthetic sweeteners in soda change how gut bacteria metabolize energy. (2) They also trigger an inflammatory response and alter (for the worse) the communities of bacteria and yeast living in your digestive tract. (3)

2. Cereal Grains: This means whole grains and refined flours that are used to make bread, pasta, cakes, and crackers. Cereal grains contain gluten and other nutrient inhibitors. As it turns out, the proteins in gluten are pro-inflammatory. They destroy the gut lining and make it “leaky.” (4)(5)

3. Vegetable Oils: This includes oils like canola, soybean, corn, and sometimes even olive oil. While not a food per-se, vegetable oils are ubiquitous in processed foods and restaurant fare. The problem? All of these oils are liquid at room temperature. This indicates that they are mostly made up of polyunsaturated fats. According to the American Journal of Clinical Nutrition, the breakdown of polyunsaturated fats is “one important mechanism involved in the pathogenesis of inflammation, cancer, and atherosclerosis.” (6)

This breakdown occurs during the manufacture of vegetable oils, during storage, and during cooking. Olive oil makes the list because many people cook with olive oil. Olive oil is rich in mono-unsaturated fats, making it modestly heat-stable but not suitable for cooking. Coconut oil and red palm oil do not make the list because they are made up of mostly saturated fats. Saturated fats can withstand high temperatures, making them ideal cooking oils.

4. Coffee: Not only does coffee trigger the release of stress hormones, we are also learning that it contains a protein very similar to a protein found in wheat gluten. This is the same protein that the immune system reacts to. In a nutshell: The immune system can “mistake” the protein in coffee for the protein in wheat—your body may respond to coffee with the exact same inflammatory response that it has with gluten. This is called a cross-reaction.

If you are not getting results from your gluten-free and casein-free diet, you may want to nix the coffee. A study published this January in Food and Nutrition found that coffee isn’t the only culprit. The proteins in milk, oats, corn, and rice are also at greater risk for being tagged by your immune system as gluten. (7) Interestingly, researchers found that instant coffee was the most cross-reactive of all forms (and brands) of coffee.

5. Beer, Wine, and Spirits: Beer is made with cereal grains that contain gluten. As a fermented beverage, beer also contains living organisms that can feed Candida yeast overgrowth. Both gluten and Candida contribute to leaky gut. As far as wine and other spirits go, it looks like alcohol itself can irritate the gut lining.

Research has found that alcohol directly damages cells along the digestive tract. (8) Alcohol also drives inflammation in the gut and makes it leaky. (9) Finally, alcohol changes your inner ecosystem and can contribute to bacterial overgrowth, or dysbiosis. (10)(11)

What To Remember Most About This Article:

Within your delicate inner ecosystem, your immune system communicates directly with bacteria and yeast in your gut. In turn, your immune system sends signals to the rest of your body.

If you have experienced digestive issues like heartburn, constipation, gas, or diarrhea, your inner ecosystem could be in trouble. A damaged inner ecosystem could also trigger symptoms like depression, migraines, eczema, or allergies.

Improving your inner ecology is easier than it seems. Avoiding 5 foods can support digestion and boost your overall health:

  1. Soda: Both natural and artificial sweeteners can change how gut bacteria metabolize energy.
  2. Cereal Grains: Gluten, found in whole grains and refined flours, is pro-inflammatory and can destroy the gut lining.
  3. Vegetable Oils: Vegetable oils made up of polyunsaturated fats may contribute to inflammation, cancer, and atherosclerosis.
  4. Coffee: Protein in coffee may be mistaken for gluten protein by the body to trigger an inflammatory response.
  5. Alcohol: Beer contains gluten-rich cereal grains, as well as living organisms that can feed Candida yeast. All forms of alcohol can irritate the gut lining.


  1. O'Hara AM, Shanahan F. (2006). The gut flora as a forgotten organ. EMBO reports, 7(7), 688-693.
  2. Payne, et al. (2012) Gut microbial adaptation to dietary consumption of fructose, artificial sweeteners and sugar alcohols. Obesity Reviews.
  3. MY Pepino, et al. (2011). Non-nutritive sweeteners, energy balance, and glucose homeostasis. Current Opinion in Clinical Nutrition & Metabolic Care, Jul; 14 (4): 391 – 395.
  4. F Pineau, et al. (2007). Intestinal translocation capabilities of wheat allergens using the Caco-2 cell line. J. Agric. Food Chem, 55 (11): 4576–83.
  5. SN Vogel, et al. (2006). Gliadin stimulation of murine macrophage inflammatory gene expression and intestinal permeability are MyD88-dependent: role of the innate immune response in Celiac disease. J. Immunol, 176 (4): 2512–21.
  6. Eritsland J. (2000). Safety considerations of polyunsaturated fatty acids. The American journal of clinical nutrition, 71(1), 197S-201S.
  7. Vojdani A, Tarash I (2013). Cross-Reaction between Gliadin and Different Food and Tissue Antigens. Food and Nutrition, 4, 20-32.
  8. Oliver KM, Taylor CT, Cummins EP. (2009) Hypoxia. Regulation of NF␣B signalling during inflammation: the role of hydroxylases. Arthritis Res Ther, 11:215.
  9. Bode C, Bode JC. (2003) Effect of alcohol consumption on the gut. Best Pract Res Clin Gastroenterol, 17:575–92.
  10. Bode JC, Bode C, Heidelbach R, Durr HK, Martini GA. (1984) Jejunal microflora in patients with chronic alcohol abuse. Hepatogastroenterology, 31:30–34.
  11. Hauge T, Persson J, Danielsson D. (1997)Mucosal bacterial growth in the upper gastrointestinal tract in alcoholics (heavy drinkers). Digestion, 58:591–95.

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  • cathy

    food was not this harmful growing up..... companies are fueling everything with pesticides so much, your practically eating your health away organic food(the way food was grown) is so expensive you almost have to get a second job to eat healthy...darn shame

  • Geri Roble

    I recently discovered I have lyme disease, I don't seem to have it severely as others. I don't really understand that, but I have cut out a good amount of wheat, sugar, and dairy. I didn't realize coffee was a problem too, perhaps this is why I feel terrible again. Thanks for the advise.

  • The Omnivore

    Very helpful information. I find that sprouted wheat doesn't affect me in the same way that regular GMO-processed wheat did. I do still drink wine (although I stopped beer after discovering that every time I drank it I ended up with a terrible stomachache) but always pair it with protein so as to sop up the sugars.

  • Thomas Lee

    In the beer manufacturing process, it will pass through a "tunnel pasteurizer" where the temperature of the beer is raised about 60 °C, so how can beer also contains living organisms that can feed Candida yeast overgrowth ?

  • Marian

    I have been studying BED for some time now and practicing the principles as best I can -- and I am getting better all the time I am certain this protocol will help me find relief from long-time problems. I see so many questions posted. I would like to share that to find answers one needs to first of all, STUDY the BED book. Then, read the articles posted on this Web Site -- so much good information there. AND, another great resource is Donna's radio show each week on Hay House Radio. On it she has guests who have great knowledge and input, plus she answers questions. I am learning a little at a time and am making fermented vegetables -- yesterday I made my first kefir. There is so much to learn and get an understanding about how the whole wheat/grains/gluten thing works. Start with the book and keep searching -- this is the real stuff!

  • Lynn

    The study you cite about the inflammatory properties of gluten is verrry falty. Gluten from organic wheat is a prebiotic and supports gut integrity. It is the gluten from GMO wheat that is now inflammatory since it has been altered. Please stop spreading this unfounded information. Real wheat has been used for thousands of years without causing health problems Before 1975, people were not experiencing allergic reactions to wheat products since there were few pesticides and no GMOs..

  • Chelsea

    Is organic peanut oil among the list for inflammatory oils? If so, is it safe for cooking at high temperatures?

  • lara

    you mention beer can upset your tummy because it is a fermented drink but arent all the drinks you recommend fermented ie kefir, kombucca , suakeraut. I thought fermented means it is good for you as it has benefical bacteria

  • Juana Esther Blanco

    Great! I have learned that most of the foods I eat are detrimental to my health; I feel overwhelmed and helpless, just as I felt after attending a food addicts meeting were I was told "No flour and No Sugar!" You must report you menu everyday to your sponson. Now what? What would you recommend as a start point for someone like me. Your premise goes beyond FA; I do want to be healthy and I also want to stop taking soo many medications!

    Please advise,

    Respectfully yours,

    Esther Blanco

  • Garry Brodman

    You say cereal grains are bad because of the gluten, but are they still bad if they have been soaked in salt water or a slightly acidic water and then dried so they can then be made into flour?
    And lastly, what about sour dough bread made straight from these cereal grains, i

  • Stephanie

    I've been drinking cocobiotic and noticed that it is also made from fermented grains. I'm just wondering how this differs from the fermented grains in beer. Does it also contain gluten? and why does it not also feed Candida growth? Thanks.

  • Judi

    So helpful! I had been feeling great after being gluten free but noticed my symptoms coming back so I stopped drinking my green grass juice. That didn't help. Now I see, it's the coffee, I started drinking it again several times a week and that led to sweeteners... Thank you for clearing this up for me!

  • Theresa Terry

    The info on coffee was very ineresting. This is a great website with so much good info.
    Thanks you,

  • sharon

    These articles are always so helpful and help to keep me on the BED food plan. Thank you for a new way of life.

  • saurabhdubey

    i have suffiring from digation problum since 2 year
    advice me how i relefe from it

  • Nancy Lee Trihey

    Isn't it true that all cereal grains do not contain gluten? What about rice, corn, millet, and perhaps others?.

  • Tania

    I have Rheumatoid Arthritis and have cut out gluten but use an olive oil which states on the bottle okay for frying. (I cannot get coconut oil or red palm oil where I live). I drink no alchohol beer is that okay to drink? If not and I can't drink wine or cola I cannot find anything I like to drink in an evening or when I am socialising.
    Advice please.

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