A food intolerance is defined as an inability to eat a food without experiencing an adverse reaction. Different types of food intolerances can cause varying symptoms. Although uncomfortable, lactose intolerance does not cause any permanent damage to your body 1. If left unmanaged, celiac disease can cause permanent damage to the intestines.

Physiology of Lactose Intolerance

Lactose intolerance is characterized by an inability to properly digest the milk sugar lactose 1. Normally, the cells in your small intestine produce an enzyme called lactase. This enzyme breaks down lactose into the simple sugars glucose and galactose, which can be absorbed into your bloodstream. Without lactase, lactose moves through the digestive system untouched. When it reaches the large intestine, the bacteria that normally live there begin to feed on it, producing gases as a byproduct. These gases are responsible for the symptoms associated with lactose intolerance 1.

Lactose Intolerance Symptoms

Adult-Onset Lactose Intolerance

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Symptoms of lactose intolerance are generally the same among all people with the condition 1. The most common symptoms include diarrhea, nausea, abdominal pain, gas and abdominal bloating. People with lactose intolerance usually only experience mild symptoms, but occasionally symptoms may be severe 1.

Physiology of Gluten Intolerance

When someone with celiac disease consumes gluten, it triggers an autoimmune response that sends out antibodies that attack the villi in your small intestine. When the villi are damaged, your body cannot properly absorb nutrients.

Gluten Intolerance Symptoms

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According to the National Digestive Diseases Information Clearinghouse, symptoms of celiac disease vary significantly based on several different factors. Some of these factors include the length of time a person was breastfed, the age a person started eating gluten, the amount of gluten consumed, age and the degree of the damage to the intestine.

Digestive symptoms are more common in infants and children with celiac disease.

Women may also experience missed menstrual periods, recurrent miscarriages or infertility.