Digestion. It’s the process by which foods are broken down into component molecules, mechanically and chemically speaking.
When it goes wrong, the symptoms can be expressed in a variety of ways, but essentially boil down to two things: intolerance and allergies.
Both are inconvenient, frustrating, and pass on as much judgment and weird looks as, I don’t know, someone wearing fur in a vegan restaurant. (For the record, it was faux fur…but I suppose my server didn’t realize that.)
Here’s a quick breakdown of what separates the two:
Gastrointestinal discomfort caused by a sensitivity to certain foods. An intolerance is NOT a result of an immune system reaction. An intolerance is synonymous with a sensitivity.
An allergic reaction to food, caused by a reaction of the immune system.
This poses another question – what causes an immune system reaction?
An immune system reaction is when immune cells release chemicals that cause either limited (localized) or systemic (whole-body) inflammation.
Said another way, the routes of an intolerance versus a food allergy are different. Below is a quick breakdown of the separate routes, but before we get there, this is the underlying mission/why any of this happens:
Food. It contains energy and nutrition for your body to maintain and perform. To convert food into usable energy, food passes through three bodily stages:
(1) digestion, (2) absorption, (3) elimination.
(1) Digestion breaks food into molecules small enough to be transported into enterocytes (absorptive cells in the villi of the small intestine).
(2) Absorption is the process of taking food molecules out of the GI tract (mouth, esophagus, stomach, small intestine, and large intestine) and into the circulation system. A majority of absorption takes place in the small intestine.
(3) Undigested food and waste products are then removed from the body via elimination.
With that said,
In the case of a food intolerance:
1. Food molecules have passed through the mouth, esophagus, and stomach, and now enter the small intestine.
2. Cells lining the small intestine typically produce an enzyme in response to the food molecule’s encounter. If a certain enzyme is not present, the undigested food molecule passes into the large intestine.
3. Bacteria housed in the large intestine ferment the food molecules for their energy/survival purposes, producing excess* gas and acid. Acid production draws water into the bowel, causing the intestines to expand (leading to discomfort via bloating, cramping, constipation, and diarrhea).