INDEX
- What Are Food Intolerances?
- How to recognize a food intolerance?
- Are there reliable tests to diagnose food intolerance?
- How to Treat Food Intolerances?
- Differential Diagnosis: If It’s Not Intolerance, What Could It Be?
Food intolerances are uncomfortable reactions to one or more chemical components of foods .
Today, more and more importance is given to the concept of intolerance, even if, to be honest, sometimes this tendency would seem unjustified .
Evaluating the current trend, it would almost seem that intolerances also play a role in completely unrelated processes and functions.
First of all, weight loss . So, to be fair, we would like to point out right away that: food intolerances do not hinder weight loss . If, for example, a reduction in weight was appreciated by eliminating cereals , cheeses , oil and pork and beef, it is because the diet was consequently reduced by most of the calories .
Nonetheless, that of intolerances is an “alibi” widely used by patients / borderline of eating disorders ( DCA); in particular, by anorexics.
Let me be clear, we are not alluding that intolerances do not exist , but simply that self-suggestion and the consequent psychosomatics can dominate.
On the other hand, cases of “real” intolerance can be annoying , sometimes even disabling , and – in the case of celiac disease – compromise certain organic functions to the point of sometimes causing irreversible damage – celiac disease in pregnancy is very dangerous for the fetus .
Let’s proceed.
What Are Food Intolerances?
We could define ” food intolerance “: the difficulty in digesting certain foods , or certain nutrients contained in them, and the adverse reaction that follows .
Food intolerances are not all the same but, compared to allergies – with the small exception of celiac disease – they do not stimulate the immune system – even if, sometimes, the intestinal mucosa can be significantly affected by inflammation .
Celiac disease is a “case of its own”
It is a condition characterized by reduced tolerance to gluten and some of its parts . It is not an allergy but, if neglected:
- however it determines the stimulation of IgA and IgG antibodies ( not IgE)
- compromises the integrity and functionality of the intestinal mucosa
- leads to a sometimes complex pathological picture at the base of which are local inflammationand chronic malabsorption ( celiac disease ).
Food intolerance proper causes both (subjective) symptoms and objective clinical signs , such as bloating, bloating , abdominal tension , flatulence , stomach pains , diarrhea , mucorrhea , etc., which “usually” occur a few hours after having consumed the non-tolerated factor.
As anticipated, the number of people who “believe” they have a food intolerance has increased dramatically in recent years, but it is difficult to really measure how many are truly affected by an objective condition .
Furthermore, many people “speculate” that they have a food intolerance even when the cause of the symptoms and clinical signs lies elsewhere.
Think, for example, how much similarity there could be between irritable bowel syndrome (IBS) and a “mild” (so to speak) manifestation of food intolerance .
How to recognize a food intolerance?
In “general”, people who have a food intolerance experience excess gas , abdominal pain and diarrhea and / or (late) mucorrhea . Less frequently vomiting (probably as an intestinal reflex).
Especially in subjects hypersensitive to food histamine and / or histamine-liberating foods, moreover, skin rashes and itching may also appear .
This is why the best way to check for food intolerance is to monitor symptoms and reduce / stop taking the supposedly responsible food .
All these symptoms and clinical signs occur after consuming the offending food / nutrient. The onset time can vary greatly depending on the subjectivity, composition and abundance of the meal. The same goes for the time to remission which is usually quite short – although in celiac disease it can take several weeks.
We reiterate that the similarity to other uncomfortable intestinal conditions makes the diagnosis of food intolerances often difficult .
Another “home” system that is quite useful, because it is integrative and complementary to a subsequent diagnostic process, is the food diary – in which the foods and symptoms will be noted.
Diagnosis of celiac disease
Like other food intolerances, celiac disease is also often responsible for gastrointestinal symptoms. On the other hand, the increase in screening has consequently seen an increase in cases of “atypical”, “silent” and “latent” diagnoses.
This is why, in order to recognize celiac disease, specific investigations (even more than one) are necessary such as: antibody investigation, genetic investigation, sorbitol breath test , stool examination , duodenal biopsy (even multiple) etc.
Diagnosis of lactose intolerance
Lactose intolerance is caused by the insufficiency of the lactase enzyme in the intestine .
Diagnosis is generally straightforward . Symptoms can be severe or mild, but always dose-dependent .
On suspicion, it is almost always sufficient to perform a specific breath test .
However, it should be noted that a part of the intolerant show symptoms even in the presence of a negative breath test and, on the contrary, a further slice of the population has a positive breath test but no symptoms .
Since, in adults, lactose intolerance usually does not generate any serious complications, the choice of whether or not to consume milk and derivatives is generally at the discretion of the subject – sometimes, with the support of exogenous lactase .
Diagnosis of fructose intolerance
There are two forms of fructose intolerance : one on a genetic-hereditary basis and severe, the other probably multifactorial and mild.
Mild multifactorial fructose intolerance
Mild fructose intolerance is caused by the intestine’s insufficient ability to absorb the fructose load that comes with food.
Even in this case, the diagnosis is very simple . Symptoms can be strong or mild, but even more dose-dependent than lactose.
A mildly intolerant can eat vegetables in normal portions almost without problems – on the contrary, a “severe” fructose intolerant cannot take even a few grams of the monosaccharide . It is different if in the case of large portions of sweet fruit , sucrose and corn syrup , even harmful for the mild intolerant.
Even in this case, a specific breath test is sufficient to confirm the diagnosis .
Attention! Mild fructose intolerance can “intertwine” with reduced tolerance to FODMAPs ( oligosaccharides , disaccharides, monosaccharides, polyols ).
Hereditary fructose intolerance
Caused by the deficit of fructose-1- phosphate aldolase hepatic activity , it leads to gastrointestinal disease and postprandial hypoglycemia , sweating , confusion and possible kidney damage, secondary to the ingestion of fructose.
A liver biopsy is required for diagnosis .
Diagnosis of favism
Favism is a serious intolerance that does not cause gastrointestinal symptoms.
That’s right, favism is an intolerance due to the lack of the enzyme glucose-6-phosphate dehydrogenase (G6PD), involved in the biogenetic pathway of pentose-phosphates .
The intake of some foods ( broad beans , peas ) and drugs (some analgesics , antipyretics , antimalarials , salicylates , certain chemotherapy drugs , quinidine, methylene blue , etc.) can, in the fabic, cause acute hemolysis with jaundice or haemolytic crisis .
Diagnosis of drug intolerances
Some substances with a vasoactive action can cause intolerance reactions.
Among the various ones we mention: histamine (abundant in poorly preserved fish , in badly preserved fish, etc., but which can increase following the intake of histamine-liberating foods), tyramine (in cheeses, yeasts , red wine , sauce soy ), phenylethylamine ( red wine and cocoa ), caffeine (coffee, cola drinks ), capsaicin ( chilli ), myristicin ( nutmeg ), ethyl alcohol .
To some extent, it is normal for some substances to cause vasodilation or vasoconstriction; however, the more “sensitive” people can experience excessive effects, and experience symptoms and clinical signs of various kinds ( nausea , vomiting, intestinal cramps , heat, tingling, hives , pressure changes , redness, headache , sweating, anxiety, palpitations etc.).
Scombroid (or Chinese restaurant ) syndrome is a phenomenon that affects those who tolerate little histamine and, to a lesser extent, histamine-liberating foods. In the past it was believed it could be the excess of sodium glutamate , but this is not the case.
Note : Alcohol intolerance, common in Asians, consists of a lack of the enzyme aldehyde dehydrogenase – not alcohol dehydrogenase.
There are no diagnostic tools and a diagnosis based on exclusion and observation is recommended .
Some additives at the center of numerous investigations, which however have not been confirmed in terms of evidence , are: sulphites , butylhydroxyanisole , butylhydroxyitulene, sorbates , benzoates , hydroxybenzoates, sodium nitrite and nitrate, sodium glutamate, aspartame , sorbitol.
Diagnosis of non-celiac gluten sensitivity
Non – celiac gluten sensitivity does not meet the diagnostic criteria for celiac disease.
It can only be confirmed via a gluten exclusion diet but, fortunately, it does not imply damage and complications similar to those of celiac disease.
Are there reliable tests to diagnose food intolerance?
Several companies produce tests for the diagnosis of food intolerances. Long story short: they are not reliable .
Most of it is based on the determination of IgG4, which are not markers of food intolerances (not even allergies). The positivity of IgG4 for various foods is also found in normal people; on the contrary, the increase of the same in ex-allergic people is an indicator of “reduction of allergic sensitivity”.
Most are not based on scientific evidence and are therefore not recommended by institutions – Italian Association of Dietetics and Clinical Nutrition (ADI), British Dietary Association (BDA) etc.
How to Treat Food Intolerances?
Simply by excluding foods / nutrients from the diet, or, where possible, by reducing them.
It is advisable to pay particular attention – especially to celiacs – to “residues”, cross-contamination and hidden ingredients.
For most intolerances, it is sufficient to eliminate the suspicious food for 2-6 weeks and check for symptoms.
It will therefore be necessary to try to reintroduce food to see if the symptoms recur.
Attention! Consider consulting a dietician to make sure you are getting all of the recommended daily nutrients while on the exclusion diet. Absolutely avoid limiting the diet of infants, except under the advice of a professional.
Differential Diagnosis: If It’s Not Intolerance, What Could It Be?
If you regularly suffer from diarrhea, bloating, abdominal pain or rashes , it is best to consult your family doctor first .
He could recognize the cause by evaluating symptoms and medical history. Furthermore, if necessary, he could prescribe various kinds of tests (eg a breath test).
They can give symptoms similar to food intolerance:
- irritable bowel syndrome;
- excessive stressand anxiety ;
- diverticula;
- inflammatory bowel diseases;
- intestinal dysbiosis .
