Food Allergy and Intolerance



No matter what kind of problem you might have, whether it might be a food allergy or intolerance, we are always available to help you overcome this problem with out Luton food allergy and intolerance services. 

Food allergy or food intolerance?

Around one or two people out of every 100 in the UK have a food allergy, but food intolerance is more common.

Genuine food allergy is rare. About 2% of the population and 8% of children under the age of three are affected.

What is a food allergy?

A food allergy is a rapid and potentially serious response to a food by your immune system. It can trigger classic allergy symptoms such as a rash, wheezing and itching.

The most common food allergies among adults are to fish and shellfish and nuts, including peanuts, walnuts, hazelnuts and brazil nuts. Children often have allergies to milk and eggs as well as to peanuts, other nuts and fish.

What is a food intolerance?

Food intolerances are more common than food allergies. The symptoms of food intolerance tend to come on more slowly, often many hours after eating the problem food.

It’s possible to be intolerant to several different foods. This can make it difficult to identify which foods are causing the problem.

Food intolerances can also be difficult to tell apart from other digestive disorders that produce similar symptoms, such as inflammatory bowel disease, gastrointestinal obstructions or irritable bowel syndrome (IBS).

1. Sulfite intolerance
Sulfites are preservatives used in some drinks, foods and occasionally medication. Sulfites can cause allergy like reactions (intolerances), most commonly asthma symptoms in those with underlying asthma, sometimes allergic rhinitis (hay fever) like reactions, occasionally urticaria (hives) and very rarely, anaphylaxis (severe allergic reactions). Wheezing is the most common reaction.

Sulfites are preservatives

Sulfites have been used since Roman times to preserve food flavour and colour, inhibit bacterial growth, reduce spoilage, stop fresh food from spotting and turning brown and help preserve medication and increase shelf life.

How do they work?

Sulfites release sulfur dioxide, which is the active component that helps preserve food and medication.

Asthma is the most common adverse effect

The most common adverse reactions, including wheezing, chest tightness and coughing are estimated to affect 5 to 10% of people with asthma. Symptoms are more likely when asthma is poorly controlled. However, adverse reactions to sulfites can also occur when there is no preceding history of asthma. Reactions can be mild through to potentially life threatening.

Severe allergic reactions (anaphylaxis) are uncommon

Anaphylaxis has been described, but is very rare. Symptoms include flushing, fast heartbeat, wheezing, hives, dizziness, stomach upset and diarrhoea, collapse, tingling or difficulty swallowing.

People who react to sulfites do not need to avoid sulfates or sulfur

Some drugs have a sulfate component (e.g. morphine sulfate) and most common soaps and shampoos contain compounds such as sodium lauryl sulfate; these are not allergenic and do not cause reactions in sulfite-sensitive individuals. Likewise, elemental sulfur (for example, as used in gardening) may cause respiratory irritation if inhaled but is not usually a specific problem for sulfite-sensitive individuals.

Sulfites are present in many foods

Sulfites have a useful role to play in helping preserve many foods and beverages. The addition of sulfites to some foods like beer and wine is permitted in most countries. In many countries, it is illegal to add sulfites to foods like fresh salads or fruit salads, or to meats like minced meat or sausage meat. Unfortunately, these can be added from time to time illegally.

The following is a list of the most common sources of accidental exposure to sulfites:

Common sources
Drinks Cordials, some fruit juices, beer and wine, some soft drinks, instant tea.
Other liquids Commercial preparations of lemon and lime juice, vinegar, grape juice.
Commercial foods Dry potatoes, some gravies and sauces and fruit toppings, maraschino cherries, pickled onions, Maple syrup, jams, jellies, some biscuits and bread or pie or pizza dough.
Fruit Dried apricots, and sometimes grapes will be transported with sachets of the sulfite containing preservative. Dried sultanas do not normally contain sulfites.
Salads and fruit salads Sometimes restaurant salads and fruit salads will have sulfites added to preserve their colour.
Crustaceans Sulphur powder is sometimes added over the top of crustaceans to stop them discolouring.
Meat Sulfites are sometimes added illegally to mincemeat or sausage meat.
Other foods Gelatin, coconut.

The presence of sulfites can be recognised on labelled food

Code number Ingredient
220 Sulphur dioxide
221 Sodium sulfite
222 Sodium bisulfite
223 Sodium metabisulfite
224 Potassium metabisulfite
226 Calcium sulphite
227 Calcium bisulfite
228 Potassium bisulfite

Low or no sulfite wines and beers

Sulfites are generally found at higher levels in the cask wine than bottled wine, and are at much higher concentrations in white wine than red wine, which is preserved by natural tannins. Some wine makers in Australasia produce wines that state that they do not add sulfites into the wine. Some brewers produce beer and state that they do not add sulfites. There are various technical reasons related to wine making and brewing, which may mean that very low levels of sulfites are still present, even when not deliberately added.

Sulfites are also used in some medications

Method of medication administration Medications
Topical medication Some eye drops and creams
Oral medication At the time of writing, no adverse reactions to sulfites have occurred from swallowed medication that might have been contaminated with sulfites.
Injectable medication Adrenaline (epinephrine), isoprenaline, phenylephrine, dexamethasone and some other injectable corticosteroids, dopamine, local anaesthetics/dental anaesthetics containing adrenaline and aminoglycoside antibiotics are the most common potential sources of exposure. It should be noted that even in patients with serious sulfite sensitivity, the benefit of adrenaline is considered to outweigh any theoretical risk from sulfites in an emergency.

2. Fructose or Sorbitol Intolerance
Fructose and sorbitol are two sugars that often are added to processed foods and medicines to make them taste sweet. Fructose can be found in soda pop and many fruit juice drinks. Sorbitol is found in diet products, chewing gum, candy, frozen ice treats, and some medicines (such as syrups for fevers and colds). Sometimes sorbitol and fructose are added to the same product.

Gas, abdominal bloating and pain, and diarrhea are common symptoms of fructose or sorbitol intolerance.

What Symptoms does Sorbitol Intolerance cause?

In humans with Sorbitol Intolerance, the absorption capacity for sorbitol is even lower than it is naturally. The sorbitol migrates completely into the large intestine, where bacteria break down the molecule. The resulting gases lead to severe flatulence and abdominal cramps. Moreover, sorbitol has water-binding properties. This manifests itself as diarrhea.

Individuals with Sorbitol Intolerance experience symptoms that are also typical for other carbohydrate malabsorptions (such as Fructose Malabsorption or Lactose Intolerance) even in the smallest amounts:

  • Bloating;
  • Gas;
  • Stomach pain;
  • Nausea;
  • Diarrhea.

These symptoms usually occur half an hour to two hours after the consumption of sorbitol-containing foods.

Even in otherwise healthy individuals, larger quantities of sorbitol have a laxative effect due to the limited digestibility and the water-binding property of the sugar. For this reason, all sorbitol-containing products must bear a corresponding warning to the laxative effect.

Sorbitol Intolerance

Sorbitol Intolerance (Sorbitol Malabsorption) means that the small intestine breaks down sorbitol insufficiently or not at all. Sorbitol Intolerance is not a disease, but completely normal. It is the rule, not the exception. No one can digest sorbitol like a sugar. This indigestibility is the reason that sorbitol contains fewer calories – just like other sugar alcohols. The price for this is the one that has recently been legally required to label sorbitol-containing products: “Can have a laxative effect in larger quantities”.

For people with Fructose Malabsorption or Lactose Intolerance, sorbitol is taboo: it would worsen the symptoms. In the case of fructose, sorbitol and fructose compete for the same transport and metabolic pathway.

Since the body metabolizes sorbitol to fructose, patients with a Hereditary Fructose Intolerance must also strictly avoid sorbitol.

What is sorbitol?

Sorbitol is a so-called sugar alcohol, similar to the household sugar sucrose. However, it is only about half as sweet. Sorbitol is naturally present in many fruits, especially in stone fruits, for example in plums, apricots and cherries. Because of the sorbitol, large amounts of cherries in every human being have a laxative effect – as grandmother warned the children before eating too many cherries, especially with lots of water.

Sorbitol is produced artificially in large amounts and used in many foods:

  • In contrast to sucrose, sorbitol is considered to be tooth-friendly since the bacteria metabolize sorbitol as poorly as the human body.
  • Many diet products are sweetened with sorbitol, nominally to have fewer calories.
  • Since sorbitol binds with water, it is used as a moistener – it is common in baked goods, chocolate and praline fillings and sauces. Even the bread from the baker around the corner can contain sorbitol, as it is often mixed into baking mixes. It extends the shelf life; the bread stays moist, and thus seemingly longer fresh.

Sorbitol also has a broad range of applications. It is found in cosmetic products, as well as in building materials. Manufacturers even add it to tobacco as a moisturizing agent.

Fructose (fruit sugar) intolerance

Incompletely absorbed (malabsorbed) fructose is fermented by the flora in the lower bowel resulting in the formation of gas and chemical substances, including short-chain fatty acids. The threshold of fructose malabsorption varies individually and widely. Most individuals will show malabsorption of sugars, including fructose, when very large quantities are consumed, without necessarily resulting in symptoms.

In pre-disposed individuals symptoms may be caused by an increased production of gas, increased sensitivity to gas-induced distension or some of the chemical compounds produced by fermentation, or an abnormal gut flora (microbiome).

The activity of the transport proteins determining gut absorption of fructose, such as GLUT5, is genetically determined and may be changed by inflammation or stress. Inflammation in the intestine, due to e.g. Crohn’s Disease, gastroenteritis or Celiac’s Disease, can therefore result in fructose intolerance. The microbiome can change after intestinal infections or antibiotic use. Intolerance to fructose often only becomes apparent in adulthood and must be distinguished from the rare and potentially dangerous hereditary fructose intolerance (HFI).

Fructose is found in honey, various fruit and often in sweetened snacks or drinks in daily amounts of at least 20 to 70g, depending on the local diet. Some sports and fruit drinks contain over 50g of fructose per 1000ml.

Fructose consumption has increased markedly in the last decades and high levels of consumption appear to be implicated in obesity, the metabolic syndrome (diabetes, cardiovascular and blood lipid diseases) and certain liver diseases. Fructans are not sweet and occur predominantly in vegetables and grains.

Approximately 30% of healthy adults show malabsorption of fructose doses below 50g and around 10% have symptomatic intolerance. There appear to be no major racial differences.

Up to 70% of patients with Irritable Bowel Syndrome have fructose intolerance.

This intolerance commonly appears only in adults and may be triggered by stress, inflammation, infection and antibiotic use.

Bloating, abdominal cramps and pain, diarrhea or constipation, increased intestinal sounds and gas production, reflux (e.g. acid taste in mouth, heartburn), nausea or vomiting.

The symptoms resemble those of functional disorders or Irritable Bowel Syndrome (IBS).

Up to 70% of patients with IBS have intolerance to normal amounts of fructose. Depression may be more common in both adults and children with fructose malabsorption, and can improve with dietary reduction in fructose intake. This may be due to lowered tryptophan levels in the blood. Skin rashes or hives, itching are not typical. Zinc and folic acid blood concentrations have been reported to be decreased in a proportion of fructose intolerant.

3. Sucrose Intolerance
Many patients with GSID, also known as CSID, lack sucrase, the enzyme needed for sucrose digestion. An individual with GSID cannot digest sucrose, and therefore develops gastrointestinal (GI) symptoms after eating food containing sucrose. Many patients with GSID also have irregular amounts of the enzymes required for starch digestion (isomaltase, palatinase, maltase). These patients may experience gastrointestinal symptoms from starch consumption.

GSID patients may have gastrointestinal symptoms that range from mild to severe when dietary sucrose moves through the small intestine undigested. The undigested sugar enters the colon, where bacteria exist. The bacteria feeds off of the increased amount of sugar, and fermentation occurs. The results are increased gas production and diarrhea. When substances are not absorbed in the colon and retain water, osmotic diarrhea occurs. Symptoms may differ between infants, children, and adults.

Infants and Children

Symptoms of GSID, more commonly known as Congenital Sucrase-Isomaltase Deficiency (CSID), do not begin manifesting in infants until they begin to ingest sucrose- and starch-containing foods (e.g., juices, solid foods, formula, and medications sweetened with sucrose). Infants who are breastfed may not show symptoms until formula is introduced into their diet, or they begin eating solid foods. Chronic abdominal pain, watery diarrhea, and/or failure to thrive (poor physical growth) are common GSID symptoms. Abdominal swelling (distention), gassiness, colic, irritability, excoriated buttocks (abrasions and irritations), vomiting, and diaper rash are signs of pediatric GSID. When patients show signs of dehydration, malnutrition, muscle wasting, and weakness, hospitalization may be required. However, this occurs only in a minority of patients. Children’s symptoms may be more severe than adults because they have shorter GI tracts.

GSID is sometimes misdiagnosed in infants. They are thought to have chronic, nonspecific diarrhea (toddler’s diarrhea). Older children may be misdiagnosed with Irritable Bowel Syndrome (IBS) because they have symptoms such as cramps, abdominal pain, gas, and intermittent diarrhea. Unfortunately, patients may learn to live with their symptoms and are never properly diagnosed. Other mistaken diagnoses may include milk protein intolerance, food allergies, and chronic, nonspecific diarrhea. It is important to note that GSID is a genetic disease that patients do not “outgrow.”


Adult symptoms are similar to those of infants and children, but due to the fact that they have a longer GI tract than children, their symptoms may not be as severe. In adults, patients may “learn to live with” their gastrointestinal symptoms, and assume GI issues are “normal.” Recurrent symptoms like chronic diarrhea, unexplained abdominal pain, bloating, weight loss, frequent bowel movements, gassiness, abdominal distention, and vomiting should not be ignored. Symptoms in adults may vary. They may be limited to an increase in bowel frequency, abdominal distention, and flatulence, and episodic watery diarrhea may occur upon ingestion of high levels of sucrose. Also, diarrhea may alternate with constipation, which may lead to a misdiagnosis of Irritable Bowel Syndrome (IBS). Any recurring, persistent gastrointestinal symptoms should be discussed with a gastroenterologist.

Failure to absorb dietary sucrose and starch can impact the absorption of other nutrients, and the hormonal regulation of gastrointestinal function. If carbohydrates are not absorbed properly, it slows down gastric emptying and accelerates small-intestinal transit time. This in turn contributes to malabsorption of starch, fat, and monosaccharides. The severity of symptoms can be affected by contributing factors such as the quantity of sucrose and starch consumed, the colonic bacterial activity, the absorptive capacity of the colon, the rate of gastric emptying, and the small bowel transit time.

Sucrose intolerance can be caused by genetic mutations in which both parents must contain this gene for the child to carry the disease (so-called primary sucrose intolerance). Sucrose intolerance can also be caused by irritable bowel syndrome, aging, or small intestine disease (secondary sucrose intolerance). There are specific tests used to help determine if a person has sucrose intolerance. The most accurate test is the enzyme activity determination, which is done by biopsying the small intestine. This test is a diagnostic for GSID. Other tests which can aid in the diagnosis of GSID but which are not truly diagnostic for the disease are the sucrose breath test, and a genetic test which tests for the absence of certain genes which are thought to be responsible for GSID.[5] Sucrose (also termed saccharose) is a disaccharide and is a two-sugar chain composed of glucose and fructosewhich are bonded together. A more familiar name is table, beet, or cane sugar. It was believed that most cases of sucrose intolerance were to do an autosomal recessive, genetic, metabolic disease. Based on new data patients with heterozygous and compound heterozygous genotypes can have symptom presentation as well. GSID involves deficiency in the enzyme sucrase-isomaltase, which breaks apart the glucose and fructose molecules. When disaccharides are consumed, they must be broken down into monosaccharides by enzymes in the intestines before they can be absorbed. Monosaccharides, or single sugar units, are absorbed directly into the blood.[6]

A deficiency of sucrase may result in malabsorption of sugar, which can lead to potentially serious symptoms. Since sucrose-isomaltase is involved in the digestion of starches, some GSID patients may not be able to absorb starches as well. It is important for those with sucrose intolerance to minimize sucrose consumption as much as possible. Dietary supplements or medications may be taken as a substitute for the enzyme missing or to introduce healthy bacteria into the immune system.

4.Glucose and galactose malabsorption / intolerance

Glucose and galactose are two common sugars, which are present in many foods. They are found as free sugars, but also in combination with other sugars (e.g. sucrose – table sugar – is made up of glucose and fructose, lactose – milk sugar – is made up of glucose and galactose, maltose is made up of molecules of glucose).

The malabsorption and intolerance of glucose and galactose is due to an abnormality in the SLC5A1 gene on chromosome 22 regulating a sugar transporter protein (SGLT1), leading to a decreased ability to absorb the sugars across the lining (mucosa) of the small intestine and resulting in symptoms when these sugars are eaten.

The failure to absorb the sugars from the intestine leads to massive attraction of water into the intestines and a reversible change in gut function.

Glucose-galactose malabsorption is rare, with only a few hundred cases identified worldwide, with an increased risk in cases of familial intermarriage. Up to 10% of the population may have a slightly reduced capacity for glucose absorption without significant associated health problems. This condition may be a milder variation of glucose-galactose malabsorption. Both parents of the affected individual will be carriers of the genetic defect, but generally without symptoms (autosomal recessive condition).

Symptoms begin at first exposure of infants to these sugars and avoidance will lead to subsidence of symptoms. The intolerance may become less severe or even disappear in older children.

Malabsorption and intolerance of galacto-oligosaccharides is a distinct condition and belongs to the so-called FODMAP intolerance spectrum common in functional bowel syndromes, such as Irritable Bowel Syndrome.

Glucose-galactose malabsorption commonly becomes apparent in the first weeks of a baby’s life.

Typical symptoms are severe diarrhea leading to life-threatening dehydration, destabilization of the acidity of the blood and tissues (acidosis), stomach cramps, bloating, excess gas production, vomiting, and weight loss when fed breast milk or regular infant formulas. They can, however, digest fructose-based formulas that do not contain glucose or galactose. As they get older, affected children or adults often tolerate glucose and galactose better. Glucose in the urine (glucosuria) can be observed. Kidney stones or calcium deposits in the kidneys are more frequent, as the genetic disorder can also affect the kidneys.

Genetic analysis is the most accurate test. Glucose breath testing can also be

5. MSG Allerg *(Glutamate Intolerance)

Monosodium glutamate (MSG) is used as a flavor-enhancing food additive. It has a bad reputation because many believe it can cause allergy-like symptoms and side effects.

Despite concerns, decades of research have mostly failed to demonstrate a relationship between MSG and serious reactions. People have reported reactions after eating foods with MSG, but until recently, researchers had been unable to scientifically prove the allergy.

Those sensitive to MSG may experience:

  • headache;
  • hives;
  • runny nose or congestion;
  • mild chest pain;
  • flushing;
  • numbness or burning, especially in and around the mouth;
  • facial pressure or swelling;
  • sweating;
  • nausea;
  • digestive upset;
  • depression and mood swings;
  • fatigue.

More serious symptoms may include:

  • chest pain;
  • heart palpitations;
  • shortness of breath;
  • swelling in the throat;
  • anaphylaxis.

Your doctor may ask if you’ve eaten any food containing MSG within the last two hours if they suspect you have a MSG allergy. A rapid heart rate, abnormal heart rhythm, or a reduction of airflow to the lungs may confirm an MSG allergy.

Monosodium glutamate (MSG) can be found as a flavor-booster in many packaged foods and restaurant dishes where it enhances the taste of food by stimulating nerves on the tongue and in the brain. It is especially popular in Asian cooking but is also commonly used in processed meats, canned vegetables and clear soups.

MSG is made from fermenting sugar beets, sugar cane, corn, molasses or tapioca and is considered a safe additive by the FDA when “consumed at customary levels”. However, some people are sensitive to MSG and some critics believe that MSG is an excitotoxin, which contributes to a number of long-term conditions affecting the brain.

The FDA further stated that people who chronically suffer from adverse reactions to MSG are “MSG sensitive” or “MSG intolerant”, a condition called MSG symptom complex (sometimes also referred to as Chinese restaurant syndrome).

Research shows that people who suffer from allergies or severe asthma may be susceptible to MSG sensitivity. Some studies have also found that patients with asthma may have more severe asthma attacks after ingesting MSG.

Symptoms of MSG Sensitivity

Some individuals react immediately after ingesting food that contains monosodium glutamate while others may experience symptoms up to 48 hours later. Reactions vary from patient to patient, while more than one symptom can be experienced at the same time. We do not know yet whether adverse reactions to MSG exacerbate underlying health problems, or if cumulative effects are created after consuming it over a period of years.

While symptoms may appear similar, MSG sensitivity is not a true food allergy as there is no immune system response. MSG sensitive people report experiencing both, short-term and long-term health effects. Some individuals have mild and temporary symptoms such as sweating or flushing, and long-term symptoms ranging from fatigue on one hand to hyperactivity on the other. Hence, symptoms of MSG sensitivity may include any of the following:

  • Angina;
  • Bloating;
  • Breathing difficulty (asthmatics);
  • Burning or numbness in the back of the neck;
  • Burning or numbness inside or around the mouth;
  • Chest pain;
  • Depression;
  • Diarrhea;
  • Drowsiness;
  • Facial pressure or tightness;
  • Fatigue;
  • Flushing;
  • Headache;
  • Heart palpations;
  • Heartburn;
  • Hives;
  • Hyperactivity;
  • Insomnia;
  • Joint pain;
  • Migraine;
  • Nausea;
  • Neurological disorders;
  • Rapid heartbeat;
  • Rash;
  • Runny nose or congestion;
  • Seizures;
  • Shortness of breath;
  • Sweating;
  • Tingling, warmth and weakness in the face, temples, neck, arms and upper back;
  • Weakness.

    The most serious, but rare, symptom not listed above is anaphylaxis, which involves two or more body systems, and requires immediate medical attention.

6. Wheat allergy/Gluten intolerance

A wheat allergy is an immune response to any of the proteins present in wheat, including but not limited to gluten. It’s most common in children. Around 65 percent of children with a wheat allergy outgrow it by the age of 12.

Symptoms of wheat allergy include:

  • nausea and vomiting;
  • diarrhea;
  • irritation of your mouth and throat;
  • hives and rash;
  • nasal congestion;
  • eye irritation;
  • difficulty breathing.

Symptoms related to a wheat allergy will usually begin within minutes of consuming the wheat. However, they can begin up to two hours after.

The symptoms of a wheat allergy can range from mild to life-threatening. Severe difficulty breathing, known as anaphylaxis, can sometimes occur. Your doctor will likely prescribe an epinephrine auto-injector (such as an EpiPen) if you’re diagnosed with a wheat allergy. You can use this to prevent anaphylaxis if you accidentally eat wheat.

Someone who is allergic to wheat may or may not be allergic to other grains such as barley or rye.

Symptoms of celiac disease

Celiac disease is an autoimmune disorder in which your immune system responds abnormally to gluten. Gluten is present in wheat, barley, and rye. If you have celiac disease, eating gluten will cause your immune system to destroy your villi. These are the fingerlike parts of your small intestine that are responsible for absorbing nutrients.

Without healthy villi, you won’t be able to get the nutrition that you need. This can lead to malnutrition. Celiac disease can have serious health consequences, including permanent intestinal damage.

Adults and children often experience different symptoms due to celiac disease. Children will most commonly have digestive symptoms. These can include:

  • abdominal bloating and gas;
  • chronic diarrhea;
  • constipation;
  • pale, foul-smelling stool;
  • stomach pain;
  • nausea and vomiting.

The failure to absorb nutrients during critical years of growth and development can lead to other health problems. These can include:

  • failure to thrive in infants;
  • delayed puberty in adolescents;
  • short stature;
  • irritability in mood;
  • weight loss;
  • dental enamel defects.

Adults may also have digestive symptoms if they have celiac disease. However, adults are more likely to experience symptoms such as:

  • fatigue;
  • anemia;
  • depression and anxiety;
  • osteoporosis;
  • joint pain;
  • headaches;
  • canker sores inside the mouth;
  • infertility or frequent miscarriages;
  • missed menstrual periods;
  • tingling in the hands and feet.

Recognizing celiac disease in adults can be difficult because its symptoms are often broad. They overlap with many other chronic conditions.

Symptoms of non-celiac gluten sensitivity

There is increasing evidence for a gluten-related condition that causes symptoms in people who don’t have celiac disease and are not allergic to wheat. Researchers are still trying to discover the exact biological cause of this condition, known as NCGS.

There’s no test that can diagnose you with NCGS. It’s diagnosed in people who experience symptoms after eating gluten but test negative for wheat allergy and celiac disease. As more and more people go to their doctor reporting unpleasant symptoms after eating gluten, researchers are trying to characterize these conditions so that NCGS can be better understood.

The most common symptoms of NCGS are:

  • mental fatigue, also known as “brain fog”;
  • fatigue;
  • gas, bloating, and abdominal pain;
  • headache.

Because no laboratory test exists for NCGS, your doctor will want to establish a clear connection between your symptoms and your consumption of gluten to diagnose you with NCGS. They may ask you to keep a food and symptom journal to determine that gluten is the cause of your problems. After this cause is established and your tests come back normal for wheat allergy and celiac disease, your doctor may advise you to begin a gluten-free diet. There is a correlation between autoimmune disorders and gluten sensitivity.

Living a gluten-free or wheat-free lifestyle

The treatment for celiac disease is adhering to a strict gluten-free diet. The treatment for a wheat allergy is to adhere to a strict wheat-free diet. If you have NCGS, the extent to which you need to eliminate gluten from your lifestyle depends on the severity of your symptoms and your own tolerance level

7. Histamine Intolerance

The symptoms of histamine intolerance (HIT) are caused by the inability of the body to break down histamine sufficiently. This is because of the reduced activity or presence of an enzyme called diamine oxidase (DAO), which is mainly responsible for breaking down histamine and other biogenic amines ingested through food.

Histamine plays a vital role for several of our body functions. We need a certain amount to live and function, but too much of it can cause painful symptoms involving the skin, the brain, lungs and heart and digestive system.

The reactions are diverse and often look like or mimic the symptoms of an allergy. Those who are misdiagnosed or not diagnosed at all suffer unnecessarily. Have a look at the first steps section.

Managing your diet

  • A food diary is essential!

It is important to eat foods that are low in histamine levels in accordance to your threshold. Please always remember that there is no such thing as an “histamine-free diet”!

Here are some general pointers:

  • Avoid or reduce eating canned foods and ready meals;
  • Avoid or reduce eating ripened and fermented foods (older cheeses, alcoholic drinks, products containing yeast, stale fish);
  • Histamine levels in foods vary, depending on how ripe, matured or hygienic the foods are;
  • As much as it is possible, only buy and eat fresh products;
  • Don’t allow foods to linger outside the refrigerator – especially meat products;
  • Ensure that your food preparation area (kitchen) is always kept clean – but don’t be manic!
  • Everyone has their own threshold; you will need to find yours


Low histamine level foods:

Fresh meat (cooled, frozen or fresh);
Freshly caught fish;
Chicken (skinned and fresh);
Egg yolk;
Fresh fruits – with the exception of strawberries, most fresh fruits are considered to have a low histamine level (also see histamine liberators below);
Fresh vegetables – with the exception of tomatoes;
Grains – rice noodles, yeast free rye bread, rice crisp bread, oats, puffed rice crackers, millet flour, pasta (spelt and corn based);
Fresh pasteurised milk and milk products;
Milk substitutes – coconut milk, rice milk;
Cream cheese, butter (without the histamine generating rancidity);
Most cooking oils – check suitability before use;
Most leafy herbs – check suitability before use;
Most non-citric fruit juices;
Herbal teas – with the exception of those listed below.
High histamine level foods:

Pickled or canned foods – sauerkrauts;
Matured cheeses;
Smoked meat products – salami, ham, sausages….
Beans and pulses – chickpeas, soy beans, peanuts;
Nuts – walnuts, cashew nuts;
Chocolates and other cocoa based products;
Ready meals;
Salty snacks, sweets with preservatives and artificial colourings.
Histamine liberators:


Most citric fruits – kiwi, lemon, lime, pineapple, plums…
Cocoa and chocolate;
Beans and pulses;
Wheat germ;
Additives – benzoate, sulphites, nitrites, glutamate, food dyes.
Diamine Oxidase (DAO) blockers:

Black tea;
Energy drinks;
Green tea;
Mate tea.

Yoghurt – depends on the bacteria culture used;
Egg white – it is a histamine liberator only when in its raw state.

Yeast – even though it does not contain histamine as such, yeast serves as a catalyst for histamine generation during manufacture. There is no yeast in the end product.

8. Lactose Intolerance
What is lactose intolerance?

Lactose intolerance means the body cannot easily digest lactose, a type of natural sugar found in milk and dairy products. This is not the same thing as a food allergy to milk.

When lactose moves through the large intestine (colon) without being properly digested, it can cause uncomfortable symptoms such as gas, belly pain, and bloating. Some people who have lactose intolerance cannot digest any milk products. Others can eat or drink small amounts of milk products or certain types of milk products without problems.

Lactose intolerance is common in adults. A big challenge for people who are lactose-intolerant is learning how to eat to avoid discomfort and to get enough calcium for healthy bones.

What causes lactose intolerance?

Lactose intolerance occurs when the small intestine does not make enough of an enzyme called lactase. Your body needs lactase to break down, or digest, lactose.

Lactose intolerance most commonly runs in families, and symptoms usually develop during the teen or adult years. Most people with this type of lactose intolerance can eat some milk or dairy products without problems.

Sometimes the small intestine stops making lactase after a short-term illness such as the stomach flu or as part of a lifelong disease such as cystic fibrosis. Or the small intestine sometimes stops making lactase after surgery to remove a part of the small intestine. In these cases, the problem can be either permanent or temporary.

In rare cases, newborns are lactose-intolerant. A person born with lactose intolerance cannot eat or drink anything with lactose.

Some premature babies have temporary lactose intolerance because they are not yet able to make lactase. After a baby begins to make lactase, the condition typically goes away.

What are the symptoms?

Symptoms of lactose intolerance can be mild to severe, depending on how much lactase your body makes. Symptoms usually begin 30 minutes to 2 hours after you eat or drink milk products. If you have lactose intolerance, your symptoms may include:

Pain or cramps.
Gurgling or rumbling sounds in your belly.
Loose stools or diarrhea.
Throwing up.
Many people who have gas, belly pain, bloating, and diarrhea suspect they may be lactose-intolerant. The best way to check this is to avoid eating all milk and dairy products to see if your symptoms go away. If they do, then you can try adding small amounts of milk products to see if your symptoms come back.

If you feel sick after drinking a glass of milk one time, you probably do not have lactose intolerance. But if you feel sick every time you have milk, ice cream, or another dairy product, you may have lactose intolerance.

Sometimes people who have never had problems with milk or dairy products suddenly have lactose intolerance. This is more common as you get older.

Why will your GP not diagnose intolerance or allergy

The silent killers of the 21st century?

Some conditions such as the autoimmune celiac condition (reaction to gluten) or intolerances such as lactose intolerance get a fair share of publicity and appropriate recognition from medical profession. But much of what falls outside the parameters of most common allergies, intolerances or reactions to food – is simply missed, and it is almost never investigated and often not even suspected.

When patients report certain symptoms, no matter how serious or mild, these are attributed to recognised health conditions. Let’s take a patient who visits a GP and complains of long standing severe cough and build up of mucous. The doctor is unlikely to consider a food allergy or intolerance as a possible cause. Quite likely a course of antibiotics will be prescribed for a potential bronchitis or ‘chest’ infection, and if this does not resolve the issue a further investigation including a chest x-ray is conducted. When this is inconclusive and the cough persists, the patient is subjected to further, more invasive tests to eliminate the potential cause of the cough. Yet the cause for chronic cough may be as simple as milk intolerance (or allergy). It would take a brave GP, however, to make a causal link between the investigated inflammation or infection and reaction to food or drink. It’s just not done. Yet milk allergy can be manifested as asthma, eczema, rhinitis (inflamed nose) and gastrointestinal distress, as well as bleeding and even pneumonia.

Another example: chronic back-pain. Whilst there may be multiple reasons for back pain, the one possible cause that can be determined or eliminated the fastest, is simply never investigated by most medical professionals. Many coffee drinkers suffering from chronic back pain have discovered to their surprise that their debilitating chronic back pains disappear miraculously within just a few days after… stopping drinking coffee. No pain-killers are needed, no x-rays, not even a doctor, although strong will is a must to break the habit.

Whatever the symptom or diagnosed health condition it is more than likely that food allergies and intolerance will not be on the list of possible suspects of the investigating doctor. And yet, it is the food intolerances that in the long term cause an untold damage in our bodies. Because they are not readily diagnosed and because they can go on undetected for years, whilst building up the damage, food intolerances are in fact the silent killers of the 21st century.

No matter what problem you might have, our Luton food allergy and intollerance services are here to help.

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