Sensitive or Intolerant? How to Tell the Difference by Michael Ash, DO, ND, BSc, RNT

Food sensitivities are not the same as food intolerance’s. If we interchangeably use those two terms, we can undermine genuine problems people experience when consuming provocative foods, in particular wheat and other gluten containing foods.

For this reason it is important to clearly define the difference between food sensitivity and food intolerance. According to the National Institute of Allergy and Infectious Diseases based in the USA, a food intolerance occurs when:

1) your body lacks a particular enzyme to digest nutrients,

2) nutrients are too abundant to be digested completely, or

3) a particular nutrient cannot be digested properly.¹

Symptoms of food intolerance(s) are exclusively gastrointestinal and mostly occur after sugar fermentation by the intestinal microbiota, leading to the production of gas, which causes abdominal distention, abdominal pain, and irregular bowel movements.¹ Common examples include lactose intolerance, or intolerance to excess fermentable oligo, disaccharides, monosaccharides and polyols (FODMAPs), or to lactulose.

Food sensitivities are individualistic adverse reactions to foods and adverse food reactions can include IgE and non-IgE-mediated primary immunological sensitivities.²

These reactions can be both intestinal and systemic and do not always occur in the same way when people ingest that particular nutrient. Non celiac gluten sensitivity (NCGS) is an example of food sensitivity. There have been reports that FODMAPs, rather than gluten, induce the abdominal symptoms attributed to NCGS. These findings indicate that NCGS might not be a separate entity from irritable bowel syndrome (IBS), but rather a subgroup of IBS.³

To reiterate, food intolerance can be summed up as GI symptoms secondary to fermentation of sugars by the colonic microbiota. Food sensitivity can be summed up as an immune response to nutrient-derived antigens that causes GI and extra-GI symptoms. If we understand this, we realize that IBS and NCGS are actually distinct disorders with overlapping features. In effect numerous intersecting mechanisms are triggered by different events.⁴ NCGS is characterized by symptoms that usually occur soon after gluten ingestion (or ingestion of associated FODMAPs or amylase trypsin inhibitors), then disappear with gluten withdrawal and relapse following gluten challenge, within hours or few days. Well recognized NCGS symptoms include a combination of IBS-like symptoms: abdominal pain, bloating, bowel habit abnormalities (either diarrhea or constipation), and systemic manifestations such as “foggy mind,” headache, fatigue, joint and muscle pain, leg or arm numbness, dermatitis (eczema or skin rash), depression, and anemia.

IBS tends to be chronic in nature and does not appear and disappear so easily. A person with IBS may also benefit from gluten withdrawal but also from FODMAP reduction making differential diagnosis difficult and meaning food intolerance and sensitivity may co-exist in the same person. It has also been shown that a large number of IBS individuals also have small intestinal bacterial overgrowth (SIBO), and eradication of the bacterial overgrowth, improves outcomes.⁵

Moreover, although FODMAPs can cause GI symptoms such as bloating, they inhibit, rather than cause, intestinal inflammation. And by inhibiting inflammation FODMAPS actually induce beneficial alterations to intestinal microbiota and generation of short-chain fatty acids as well as induction of key immune balancing events and repair damaged intestinal lining.⁶ Therefore, excluding these from your diet long term does not make immunological sense and working with a suitably skilled practitioner to resolve this should be a key objective of long term resolution.

References:

1. Fasano A, Sapone A, Zevallos V, Schuppan D. Nonceliac gluten sensitivity. Gastroenterology. 2015 May;148(6):1195-204 PMID: 25583468 View Abstract
2. Taylor S & Hefle S. Food allergies and other food sensitivities: A publication of the Institute of Food Technologists’ Expert Panel on Food Safety and Nutrition. Scientific Status Summary. Food Tech 2011;55:9.
3. Sapone A, Bai JC, Ciacci C, Dolinsek J, Green PH, Hadjivassiliou M, Kaukinen K, Rostami K, Sanders DS, Schumann M, Ullrich R, Villalta D, Volta U, Catassi C, Fasano A.Spectrum of gluten-related disorders: consensus on new nomenclature and classification. BMC Med. 2012 Feb 7;10:13 PMID: 22313950 View Abstract
4. El-Salhy M, Hatlebakk JG, Gilja OH, Hausken T. The relation between celiac disease, nonceliac gluten sensitivity and irritable bowel syndrome. Nutr J. 2015 Sep 7;14:92. PMID: 4561431 PMID: 10638941 View Abstract
5. Pimentel M, Chow EJ, Lin HC. Eradication of small intestinal bacterial overgrowth reduces symptoms of irritable bowel syndrome. Am J Gastroenterol. 2000;95(12):3503. PMID: 11151884. View Abstract
6. Hooper LV. You AhR what you eat: linking diet and immunity. Cell. 2011 Oct 28;147(3):489-91 PMID: 22036556 View Abstract