Food
intolerance
Food intolerance occurs when someone experiences difficulty in the digestion of certain foods, therefore expressing unpleasant physical reaction to them. Contrary to some allergies, food intolerances alone are not considered life-threatening. They are extremely common though, with up to 20% of the world’s population having one or more of them. Τhey lead to a variety of symptoms, which normally start within a few hours of consuming the food you are intolerant to. Still, some symptoms take up to 48 hours to show and can last for hours or days, making it hard to find the offending food just by observation. Food intolerance symptoms vary, but they mostly include the digestive system, skin and respiratory system.
Symptoms
The most
common symptoms involve:
Diarrhea
Bloating
Rashes
Headaches
Nausea
Fatigue
Abdominal
pain
Runny nose
Reflux
Flushing
of the skin
Diagnosis
The most common way of food intolerance diagnosis is by elimination diet. Elimination diets are designed to narrow down offending foods. In detail, foods that are mostly linked with intolerances are cut out for a period of time, until symptoms subside. Foods are then reintroduced one at a time, while inspecting for symptoms. This type of diet helps people identify which food or foods are causing symptoms.
Most common
food intolerances
Dairy
Lactose is a sugar
found in milk and dairy products.It is broken down in the body by an enzyme
called lactase, which is necessary in order for lactose to be properly digested
and absorbed. Lactose intolerance is caused by a shortage of lactase enzymes,
which causes an inability to digest lactose and results in digestive symptoms,
such as bloating, abdominal pain, diarrhea, gas and nausea. It can be diagnosed
with a lactose-tolerance test, lactose breath test or a stool PH test. People
with lactose intolerance should avoid dairy products (milk, ice cream).
Gluten is the general name given to
proteins found in wheat, barley, rye and triticale. Several conditions relate
to gluten, including celiac disease, non-celiac gluten sensitivity and wheat
allergy. Celiac disease involves an immune response, which is why it is
classified as an autoimmune disease.When people with celiac disease are exposed
to gluten, the immune system attacks the small intestine and can cause serious
harm to the digestive system. Symptoms of non-celiac gluten sensitivity are
similar to those of celiac disease and involve bloating, abdominal pain,
diarrhea or constipation, headaches, fatigue, joint pain, skin rash, anemia and
anxiety. Both celiac disease and non-celiac gluten sensitivity are managed with
a gluten-free diet.
Caffeine is a bitter chemical that is found
in a wide variety of beverages, including coffee, soda, tea and energy drinks.
It’s a stimulant, meaning it reduces fatigue and increases alertness when
consumed. It does so by blocking receptors for adenosine, a neurotransmitter
that regulates the sleep-wake cycle and causes drowsiness/dehydration. Some
people are more sensitive to caffeine and experience reactions even after
consuming a small amount. This hypersensitivity to caffeine has been linked to
genetics, as well as a decreased ability to metabolize and excrete caffeine.
Some symptoms include rapid heartbeat, anxiety, jitters, insomnia, nervousness
and restlessness. People with a sensitivity to caffeine should minimize their intake
by avoiding foods and beverages that contain caffeine, including coffee, soda,
energy drinks, tea and chocolate.
Salicylates are natural chemicals that are
produced by plants as a defense against environmental stressors like insects
and disease. They have anti-inflammatory properties for the plants and can be
found in a variety of foods, including fruits, vegetables, teas, coffee,
spices, nuts and honey. Salicylates are also used as a food preservative and
may be found in medications. Symptoms of salicylate intolerance include stuffy
nose, sinus infection, asthma, diarrhea, colitis and hives. Those with
salicylate intolerance should avoid spices, coffee, raisins and oranges, as
well as cosmetics and medications that contain salicylates.
Amines are produced by bacteria during
food storage and fermentation and found in a wide variety of foods. Though
there are many types of amines, histamine is most frequently associated with
food-related intolerances. It is a chemical in the body that plays a role in
the immune, digestive and nervous systems. It helps protect the body from
infection by creating an immediate inflammatory response to allergens. This
triggers sneezing, itching and watery eyes in order to potentially excrete
harmful invaders.The most common reason for histamine intolerance is impaired
function of the enzymes responsible for breaking down histamine — diamine
oxidase and N-methyltransferase. Symptoms of histamine intolerance include
flushing of the skin, headaches, hives, itching, anxiety, stomach cramps and
low blood pressure. People with an intolerance to histamine should avoid foods
like cured meats, citrus fruits, avocados, aged cheeses, vinegar and smoked
fish.
FODMAPs is an abbreviation that stands for fermentable
oligo-, di-, monosaccharides and polyols.
They are a group of short-chain carbohydrates found naturally in many foods
that can cause digestive distress. FODMAPs are poorly absorbed in the small
intestine and travel to the large intestine, where they are used as fuel for
the gut bacteria there. The bacteria break down or “ferment” the FODMAPs, which
produces gas and causes bloating and discomfort. These carbohydrates also have
osmotic properties, meaning they draw water into the digestive system, causing
diarrhea and discomfort. Symptoms of a FODMAP intolerance involve bloating,
diarrhea, gas, abdominal pain, and constipation. FODMAP intolerances are very
common in people with irritable bowel syndrome (IBS). In fact, up to 86% of
people diagnosed with IBS experience a reduction in digestive symptoms when
following a low-FODMAP diet. There are many foods high in FODMAPs, including
apples, soft cheeses, honey, milk, artichokes, bread, beans, lentils and beer.
Sulfites are chemicals that are primarily
used as preservatives in foods, drinks and some medications. They can also be
found naturally in some foods like grapes and aged cheeses. Sulfites are added
to foods like dried fruit to delay browning and wine to prevent spoilage caused
by bacteria. Sulfite sensitivity is most common in people with asthma, though
people without asthma can be intolerant to sulfites as well. Common symptoms of
sulfite sensitivity include hives, skin swelling, stuffy nose, hypotension,
flushing, diarrhea, wheezing and coughing. Sulfites can even cause airway
constriction in asthmatic patients with sulfite sensitivity, and, in severe
cases, it can lead to life-threatening reactions.
Fructose, which is a type of FODMAP, is a simple sugar found in fruits and vegetables, as well as sweeteners like honey, agave and high-fructose corn syrup. In people with fructose intolerance, fructose isn’t efficiently absorbed into the blood. Instead, the malabsorbed fructose travels to the large intestine, where it is fermented by gut bacteria, causing digestive distress. Symptoms of fructose malabsorption include reflux, gas, diarrhea, nausea, abdominal pain, bloating and vomiting. People with an intolerance to fructose are often also sensitive to other FODMAPs and can benefit from following a low-FODMAP diet.
Celiac Disease
Coeliac disease is a condition
where your immune system attacks your own tissues when you eat gluten.
This damages your gut (small intestine) so you are unable to take in nutrients.
Coeliac disease is caused by a reaction to gluten, a group of various proteins
found in wheat and in other grains such as barley and rye and can cause a range
of symptoms, including diarrhoea, abdominal pain and bloating, loss of
appetite, and among children failure to grow normally.
Non-classic symptoms are more
common, especially in people older than two years. There may be mild or absent
gastrointestinal symptoms, a wide number of symptoms involving any part of the
body, or no obvious symptoms. Coeliac disease was first described in childhood;
however, it may develop at any age. It is associated with other, such as Type 1
diabetes mellitus and Hashimoto's thyroiditis, among others.
It usually occurs in people who are
genetically predisposed. Upon exposure to gluten, an abnormal immune response
may lead to the production of several different autoantibodies that can affect
a number of different organs. In the small bowel, this causes an inflammatory
reaction and may produce shortening of the villi lining of the small intestine
(villous atrophy).This affects the absorption of nutrients (iron, vitamin K, copper and zinc, folic acid, calcium,
vitamin D, vitamin B12 and selenium) , frequently leading to anaemia.
The only known effective treatment is a strict lifelong gluten-free diet, which leads to recovery of the intestinal lining (mucous membrane), improves symptoms, and reduces the risk of developing complications in most people. If untreated, it may result in cancers such as intestinal lymphoma, and a slightly increased risk of early death. Rates vary between different regions of the world, from as few as 1 in 300 to as many as 1 in 40, with an average of between 1 in 100 and 1 in 170 people.It is estimated that 80% of cases remain undiagnosed, usually because of minimal or absent gastrointestinal complaints and lack of knowledge of symptoms and diagnostic criteria. Coeliac disease is slightly more common in women than in men.