Food Intolerance

How to recognize food intolerances


Food Intolerances

Though sometimes mistaken for food allergies, food intolerances elicit a different response in the body. Lactose intolerance, gluten intolerance and food sensitivities are all examples of food intolerances.


Lactose Intolerance
Individuals with lactose intolerance have insufficient levels of the enzyme lactase, which breaks down the sugar lactose, naturally found in dairy products, during digestion. With insufficient amounts of lactase, bacteria in the gut will break down lactose, which may result in gas, bloating, abdominal pain and diarrhea within 30 minutes to 2 hours after consuming lactose.

Lactose Intolerance in Infants
Congenital lactase deficiency is a rare disorder in infants that can result in severe diarrhea and therefore dehydration and weight loss. In adults, lactase levels typically decline with age making lactose intolerance more common as we get older. Premature birth, bowel surgery, bacterial or viral infection of the small intestine, intestinal disease such as celiac sprue and lack of lactase production in the small intestine can all contribute to lactose intolerance.

The prevalence of lactose intolerance remains unclear. However, lactase deficiency is most common in people of East Asian decent and it is also common in people of West African, Arab, Jewish, Greek and Italian decent as well as Hispanic Americans, Native Americans, Alaska Natives and Pacific Islanders.

Diagnosing Lactose Intolerance
Lab tests for lactose intolerance include the lactose tolerance blood test and hydrogen breath test. Treatment may involve switching to lactose free milk or using over-the-counter lactase enzymes. However, individuals with lactose intolerance can typically consume at least 12 grams of lactose (the equivalent of 8 oz. of milk) with no problems and tolerate hard cheeses (0.3 – 1 grams lactose per 1.5 oz) and yogurt well (11-17 grams of lactose per cup though fermentation breaks down much of the lactose).

It is important to note that many people who avoid dairy typically do not consume adequate amounts of calcium and vitamin D. Therefore, diet and supplement strategies should be used to ensure adequate intake of these nutrients.

Food Additives
Food additives are ingredients used to enhance specific attributes of a food, including taste or color or protect against microbial growth. The food additives monosodium glutamate (MSG) and sulfites can cause adverse reactions in some people.

After consuming large amounts of the flavor enhancer MSG, those who are MSG intolerant may experience flushing, sensations of warmth, headaches or chest discomfort. Sulfites occur naturally in some foods, are created during the production of others and added to foods to increase crispness or prevent mold growth. Sulfites can exacerbate breathing problems in asthmatics. Ingredient labels indicate when sulfites are added to foods.

Celiac Disease, or Gluten Intolerance

Celiac disease (gluten intolerance or gluten-sensitive enteropathy), is an autoimmune disease that affects the digestive system leading to damage in the small intestine and malnourishment. Ingestion of the protein gluten, found in wheat, rye and barley, causes an immune reaction that leads to destruction of the villi in the small intestine, fingerlike projects that help absorb nutrients from food.


Symptoms of Gluten Intolerance
Individuals with celiac disease may have no symptoms or any of the following symptoms (adults, in particular, may experience no gastrointestinal symptoms):

  • gastrointestinal issues such as stomach pain, gas or diarrhea
  • extreme tiredness
  • change in mood
  • weight loss
  • itchy rash (dermatitis herpetiformis)
  • slowed growth (infants and children)
  • unexplained iron-deficiency anemia
  • fatigue
  • bone or joint pain
  • arthritis
  • bone loss or osteoporosis
  • depression or anxiety
  • tingling numbness in the hands or feet
  • seizures
  • missed menstrual periods
  • infertility or recurrent miscarriage
  • canker sores in the mouth


Celiac disease affects more than 2 million Americans or approximately 1 in 133 people. However, an estimated 90% remain undiagnosed. Yet early detection may improve gastrointestinal health and quality of life.

Blood tests can be used to diagnose celiac disease though false negatives can occur. If celiac disease is suspected after a negative blood test, intestinal bioposies should be taken (a minimum of 4-6 biopsies including at least one of the duodenal bulb).

Treatment for celiac disease involves strict avoidance of gluten. Following a gluten-free diet means avoiding wheat, barley, rye and foods and ingredients made from these grains in foods, dietary supplements, medicines and lip balms.

Gluten Sensitivity
Gluten sensitivity is a gluten-associated disorder that is distinctly different from celiac disease. Gluten sensitive individuals do not have small intestine damage but may experience abdominal pain, fatigue, headaches, “foggy mind” and tingling of the extremities. An estimated 6% or 18 million people in the U.S. are gluten sensitive. At the current time there are no diagnostic tests for gluten sensitivity.

Food allergies, intolerances and other reactions to food, including food poisoning and histamine toxicity can sometimes be confused with each other. Therefore, a proper diagnosis is very important so a preventative diet or treatment program can be put in place.


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