The digestion of the three nutritional principles that provide energy takes place 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 system function correctly in certain ranges of conditions beyond which disturbances are triggered in thedigestion . 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), to avoid sugars at the end of the meal (eg fruit and sweets) and to avoid acidic drinks at the meal.
Poor digestion leads to 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 diseases such as bronchitis , pharyngitis , cystitis , otitis, etc.
Food allergies and intolerances
Food allergiesandintolerancesfall 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 noticed the negative effects due to the ingestion ofcow’s milk.If the immune systemintervenes in these reactions it is a matter offood allergies, otherwise of food intolerances (the most common). However, adverse reactions to food still constitute one of the most controversial areas of medicine today as the physiological mechanisms, clinical symptoms and diagnosis are not always clear.
Food allergy
Due to hypersensitivity to allergens, that is 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-allergicsyndrome with papulesor vesicles inthe mucosa, sucklingcolic ), cutaneous ( eczema or topical dermatitis, urticaria , angioedema ), respiratory ( asthma 5.7% in children, 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.
The treatment for food allergies, 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). Generally they are due to drugs and food additives ( tartrazine which is the yellow dye of many drinks; sodium benzoate in soft drinks and sweets, bisulfite in wineandbeer , salicylate prohibited by law but often present in fruit and vegetables , 4-hydroxybenzoic acid from from the processing of pastaandbread,vanillin in desserts, etc.).
Some foods can also cause these syndromes if they are rich in histamine(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 still green tomatoes and peppers , in auberginesandpotatoesin sprout, (cooking reduces the initial concentration by 40-50%).
Food intolerance symptoms are varied and are generally dose-dependent; the most evident symptoms are bloating andabdominal pain,nausea,flatulence,diarrhea, burning in the throat but alsofatigue, headache , greater tendency to contract inflammation,colds,flu, etc.
The most common form of wheat intolerance isceliac disease, while talk oflactose intoleranceit is, as we have seen previously, a mistake since it is a physiological interruption of the production of the enzyme lactase, 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 , it retains sodiumand water with 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 (it makes them better accepts the patient and facilitates their 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.
Defend yourself
Good quality of raw materials, fruit, vegetables and ripe and seasonal vegetables, maximum cleanliness and hygiene of the environment and personal, avoid marble and wood ( bacteria lurk in their holes ) and use steel and ants, hands that are not chapped or wounds (receptacles of staffilococchi), cooked food put back in the fridge immediately (bacterial proliferation starts again as soon as the temperature of the food is below 60 °), avoid raw meat (responsible for 70% 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 inthe adipose tissuethat protects them during cooking), the pollutants remain unchanged. Finally, follow a correctdietary education(which eventually includes the elimination of foods that have been proven intolerant (allergy) and lifestyle habits as healthy as possible (avoiding continuousstress, doing moderatephysical activity, sleeping a sufficient number of hours etc.)