Food intolerance is also called as non-IgE mediated food hypersensitivity or non-allergic food hypersensitivity, which means complexity in digesting certain food items. It is significant to note down that food intolerance is unlike food allergy.

Food hypersenstivities activate the immune system, whereas food intolerance does not. It is usually considered as a difficulty in digesting certain food items and having an unpleasant reaction towards it.

SYMPTOMS:
The symptoms of an intolerance to food include those of an upset digestion –

• Diarrhea, bloating, upset stomach, etc.
• Weight loss, lethargy or anemia
• Migraine headaches and psychological effects such as confusion and even depression.

Crohn’s disease and Irritable Bowel Syndrome which are the diseases of digestive system are also considered as the symptoms of food intolerance.
 
CAUSES:

• Absence of an enzyme: To digest a food, enzymes are necessary and their absence will lead to food intolerance. For example: lactose intolerant people have missing lactose enzyme.
• Chemical causes: Certain chemicals like caffeine in coffee and tea will cause food intolerance.
• Food poisoning: Certain toxins in food can lead to diarrhea, nausea and vomiting.
• Histamine in some foods: When certain foods like fish are rot, it leads to accumulation of histamine. And it leads to development of diarrhea, vomiting and nausea.

 
TYPES OF FOOD INTOLERAANCE:

• Lactose
• wheat
• gluten
• caffeine
• histamine, present in mushrooms, pickles, and cured food
• additives such as artificial sweetners, coloring, or other flavorings

 
DISEASES ASSOCIATED WITH FOOD INTOLERANCE:

• Diarrhea: Diarrhea is a general problem that can arrive rapidly or be a chronic illness. The possible cause of diarrhea can comprise food poisoning, infections, food hypersenstivities or intolerances, and medication. Lactose intolerance, the inability to digest the sugars in milk, is the most common cause of diarrhea/ however it’s possible to have intolerance towards other foods like fructose, salicylates, amines, etc. In such cases diarrhea lasts for more than four weeks and is triggered by a specific food. The symptoms appear withintwo to 12 hours. And the appearance is Watery, sometimes contains mucous.

• Celiac disease: Celiac disease which is also known asceliac sprue, is an unpleasant response to the protein gluten. Gluten which is present in foods like wheat, rye, barley and sometimes oats. People having celiac disease must strictly keep away from these grains and their by-products for the rest of their lives. Celiac disease symptom include bloating and gas, diarrhea, constipation, headaches, itchy skin rash and pale mouth sores. The signs and symptoms may differ among affected persons.

• Migraine: Migraines are a neurological illness differentiated by attack of headache of strong or moderate intensity, as well as other neurological symptoms. Intolerance to gluten can lead to gluten, histamine, amines and Monosodium glutamate. The most common symptoms include: -– A severe, throbbing and prolonged headache which can last anywhere between 4 hours and 3 days
  – The headache will often get worse with movement
  – Nausea
  – Vomiting
  – Increased sensitivity to light or sound
  – Stomach upset
  – Sweating
  – Feeling either very cold or very hot
  – Difficulty with concentration

• Hives: Hives, also identified as urticaria, affects nearly about 20 percent of people at some time throughout their lives. It can be trigger by many substance or situation and usually starts as an itchy patch of skin that turn into distended red welt. Some food (especially peanuts, eggs, nuts and shellfish) can trigger hives. It is intolerant to salicylates, amines and sulfites. The symptoms may include:
  • Batches of red or skin-colored welts (wheals)
  • Welts that vary in size, change shape, and appear and fade repeatedly as the reaction runs its course.
  • Itching

• Psoriasis: Psoriasis is a common chronic skin disorder which is affecting over millions of people. There is no treatment for psoriasis and management is directed at controlling patients’ symptom. Psoriasis is an inflammatory condition. Research is restricted, but a few people who have psoriasis say they can control it better if they eat more inflammation-fighting foods. Gluten free diet also helps in controlling psoriasis.

• Asthma: Asthma is a common lasting inflammatory illness of the airways of the lungs. It is characterized by uneven and chronic symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms of asthma are the following:
  • episodes of wheezing
  • coughing,
  • chest tightness
  • shortness of breath

The foods which lead to asthma can include salicylates and sulfites and histamines.

• Arthritis: Osteoarthritis involves inflammation which is caused by deterioration of a person’s joint and is due to chronic wear and tear – something many doctors understand all too well. Rheumatoid arthritis is a more general term used to describe pain, inflammation and swelling of a person’s joints. Dietary factors may influence inflammatory response in RA. Gluten intolerance can lead to arthritis.

• Psychosis and schizophrenia: Schizophrenia represents a broad illness range with symptomatic features and severity ranging from strange behavior to paranoia.  Gluten is considered as a trigger for psychosis. Intolerance to gluten represents one of the most famous food allergy present in recent history, delivering deep impact to both physical and mental health.

• Diabetes: It is a condition that impairs the body’s capacity to process blood glucose, otherwise known as blood sugar. Some form of food intolerance that results in weight gain, diabetes and other complications . Various research studies show that modern foods like grains and milk products are responsible for the development of diabetes.  That means one could prevent millions of pre-diabetics from developing the disease – simply by suggesting they ‘switch a few foods’. Food intolerance leading to diabetes can be due to:
  • Grass grains like barley, wheat and oats (Gluten)
  • Nightshade vegetables
  • Milk products (Diary)

MANAGEMENT OF FOOD INTOLERANCE:
The easiest way to manage food intolerance is to get rid of the responsible food/s from the diet. Sometimes, the body can stand the food if it is avoided for a moment in time, then reintroduced in little doses, chiefly for food intolerances.
Before you get rid of or reintroduce foods, look for recommendation from a expert doctor and dietitian.