The digestion of the three nutritional principles that provide energy occurs in different and sequential phases: carbohydrates in the mouth, stomach and small intestine , proteins in the stomach and small intestine, lipids in the small intestine.
All foods , with very rare exceptions, are made up of a combination of nutritional principles: this does not mean that we can eat anything but that our organs have certainly adapted to natural combinations, much less to human food manipulations.
The enzymes of the digestive systemthey function properly in certain ranges of conditions beyond which digestive disturbances are triggered . Each enzyme is specific in its action, even within the same food category.
By carefully combining foods , digestion and absorption are improved.
To this end, it is good, and easily feasible, to avoid combining multiple protein foods together (especially meat , eggs , cheese), avoid sugars at the end of the meal (eg fruit and sweets) and avoid acidic drinks at the meal.
A poor digestioninvolves less assimilation and greater waste of energy, fermentations and putrefactions with the production of toxic gases and substances such as: indole, phenol , ammonia (NH3), acetic acid and lactic acid . Once absorbed, the latter cause lowering of the immune defenses , humoral acidity, increase in the internal temperature of the intestine, alteration of the intestinal microflora ; a favorable environment is created for the development of pathogenic and sub-pathogenic microflora capable of causing local and remote inflammatory pathologies such as bronchitis , pharyngitis , cystitis, otitis etc.
Food allergies and intolerances
Food allergies and intolerances fall into the broad group of disorders defined as adverse reactions to food . The first observations on disorders related to food ingestion are very old: Hippocrates , for example, had already noted the negative effects due to the ingestion of cow’s milk . If the immune system intervenes in these reactions it is a matter of food allergies , otherwise of food intolerances (the most common). However, adverse reactions to food are still today one of the most controversial areas of medicine as the physiological mechanisms, clinical symptoms and diagnosis are not always clear.
Due to hypersensitivity to allergens or to glycoproteins present in foods (especially in milk, eggs, fish , crustaceans , peanuts , soy , tomatoes , wheat , nuts ) and additives ( egg lysozyme used as bactericide, fungal alpha- amylase used as a leavening agent , proteins used as thickeners). Handling of food can increase allergenicity (storage for apple and cod , cooking for peanuts, fish and soybean oil ).
The clinical symptomatology consists mainly ofgastrointestinal manifestations ( oral-allergic syndrome with papules or vesicles in the mucosa , suckling colic ), cutaneous ( eczema or topical dermatitis , urticaria , angioedema ), respiratory ( asthma 5.7% in the child, recurrent serous otitis media ), anaphylactic shock (la more severe, in some cases fatal). Regarding the diagnosis, laboratory tests are often insufficient, so it is essentially based on the anamnesis
and about the clinic, but it too cannot always be certain. Allergy tests often give unreliable information as the available allergens are not purified (except for some foods such as cod).
The most reliable diagnosis is obtained through the elimination diet (diagnosis by exclusion) and consists of:
- identification of the suspect food (or a small number of suspect foods);
- its elimination from the diet for 2-3 weeks;
- its reintroduction into the diet for another 2-3 weeks.
If symptoms go away during the time the food is removed from the diet and recur once reintroduced, it is very likely an adverse reaction to food. In this case it is necessary to perform a differential diagnosis of allergy / intolerance, verifying, through appropriate tests, the involvement or not of the immune system.
Treatment for food allergies, as well as for intolerances, consists in eliminating from the diet or consuming in small quantities the foods that cause the reaction.
Pseudo- food allergies or intolerances
According to some authors only less than 20% are true food allergies, the others are food intolerances (reactions not mediated by IgE ). They are generally due to drugs and food additives ( tartrazine which is the yellow dye of many drinks; sodium benzoate in soft drinks and sweets, bisulfite in wine and beer , salicylate prohibited by law but often present in fruit and vegetables , 4-hydroxybenzoic acid from from the processing of pasta and bread , vanillin in desserts, etc.). Even some foods can cause these syndromes if rich inhistamine (some types of fish and meat , fermented drinks and fermented cheeses ) or substances capable of releasing it by non-immunological mechanism (crustaceans, beans , chocolate , tomatoes, egg whites, etc.). Poisoning can also result from unripe fruit, vegetables and greens; well known is the “poisoning” power of solanine , a glucosidic alkaloid present, as protection against fungi and insects, in tomatoes and peppers that are still green, in aubergines and potatoesin sprout (cooking reduces the initial concentration by 40-50%).
Food intolerance symptoms are varied and generally dose-dependent; the most evident symptoms are bloating and abdominal pain , nausea , flatulence , diarrhea , burning in the throat but also fatigue, headache , greater tendency to contract inflammation, colds , flu, etc.
The most common form of wheat intolerance is celiac disease , while talk of lactose intoleranceit is, as we have seen previously, an error as it is a physiological interruption of production of the lactase enzyme , post- weaning , which occurs in the majority of the population. In this regard, it may be useful to point out some cheeses low in lactose: parmesan , emmental , cheddar , edam . Finally, it is important to read food labels as lactose is used as a sweetener ( sweetener ) and excipient ( thickener , retains sodium and waterwith obvious economic advantages for the food producer thanks to the weight gain of the product) in many foods ( sausages , cooked ham , preserved meat, frankfurters , ready meals, snacks, chips, etc.) and medicines (makes them better accepted for patient and facilitates industrial preparation).
The “alternative tests” for the diagnosis of food intolerances are without scientific reliability and have not yet demonstrated clinical efficacy.
NB: the powders in the air hypersensitize the immune system, facilitating the onset of allergies and intolerances.
Good quality of raw materials, fruits, vegetables and ripe vegetables and season , cleanliness and hygiene and personal ambience, avoiding marble and wood (in their holes lurk the bacteria ) and use steel and formica, hands not cracked or injured (receptacles of staffilococchi), cooked food put back in the fridge immediately (bacterial proliferation starts again as soon as the food temperature is below 60 °), avoid raw meat (responsible for 70% of food infections ). In some cases, cooking helps: a few minutes at 85 ° C are enough to deactivate the active ingredient of antibiotics .
Among the pesticides the most resistant to heat are organochlorines (they accumulate in the adipose tissue that protects them during cooking), the pollutants remain unaltered. Finally, follow a correct dietary education (which eventually includes the elimination of foods for which intolerance has been proven (allergy) and lifestyle habits as healthy as possible (avoiding continuous stress , doing moderate physical activity, sleeping a sufficient number of hours etc.).