Classification of diet-related diseases
Pathologies caused by the alimentary (food) factor are divided into several broad groups. Food poisoning itself belongs to Group VII and is classified into three categories:
- Of bacterial origin.
- Of non-bacterial origin.
- Of unknown etiology.
Closely related to them is Group VI — infectious and parasitic diseases, where food acts as a vehicle for transmitting the pathogen. Infectious diseases include salmonellosis, shigellosis, and foot-and-mouth disease. Parasitic infestations (helminthiases) include opisthorchiasis, diphyllobothriasis, trichinosis, ascariasis, and trichuriasis.
The remaining groups of pathologies do not arise from toxins or microbes, but as a result of violating healthy eating rules:
- Group III — diseases of excessive nutrition. An excess of energy and carbohydrates leads to obesity and diabetes. An excess of protein triggers gout, while fats provoke atherosclerosis and ischemic heart disease. Excessive intake of vitamins causes hypervitaminosis (A, D, C). Excess minerals are also toxic: fluorine leads to fluorosis, calcium to calcinosis, phosphorus to osteochondrosis, and iron to siderosis.
- Group IV — diseases of improper food combining. They manifest as food intolerance (allergies, enzymopathies) and enteritis. Classic triggers of enteritis include combining milk with salted herring or fresh cucumbers.
- Group V — diseases of improper eating habits. Irregular meals cause gastritis, gastric and duodenal ulcers, and exacerbate the development of obesity and atherosclerosis.
Functions of food in the body
To prevent poisoning and alimentary diseases, it is important to understand that food does not simply fill the stomach, but also performs a number of critically important tasks. They are divided into classical and additional functions.
The classical functions include:
- Energy function: supplying the body with heat through carbohydrates and fats (bread, grains, sugar, potatoes, animal and vegetable oils).
- Plastic function: supplying building materials (primarily proteins and mineral salts) for cells and tissues. Main sources are meat, fish, eggs, and dairy products.
- Regulatory (biological) function: controlling metabolism through the synthesis of hormones and enzymes, for which proteins, vitamins, trace elements, and polyunsaturated fatty acids (PUFAs) are necessary.
In the course of research, additional functions of nutrients were identified:
- Protective and immune function: maintaining the body's ability to resist external threats. Antibodies protect against biological agents (pathogens). Detoxification, sorption, and excretion mechanisms protect against chemical agents (xenobiotics). Protection against physical factors (temperature, radiation) occurs through the regulation of sweating. Key substances here are proteins, essential PUFAs, selenium, zinc, iodine, and iron.
- Adaptive and regulatory function: adaptation of the digestive, thermoregulatory, and excretory systems. Provided by water, pectin, and dietary fiber (found in grains, vegetables, and fruits).
- Signaling and motivational (social-motivational) function: maintaining food motivation and appetite through taste qualities. Delicious food more actively stimulates the secretory and motor functions of the gastrointestinal tract, which improves digestion.
- Rehabilitation function: recovery after illnesses.
Metabolism and energy value
Metabolism consists of two opposite, but interrelated processes:
- Dissimilation (catabolism): the breakdown of cells and intracellular structures with the excretion of metabolic products. This process occurs constantly and does not depend on food intake.
- Assimilation (anabolism): the formation of new cells, growth, and renewal of structures. It requires energy expenditure and is only possible when plastic substances are supplied with food.
Interestingly, part of the amino acids necessary for daily synthesis is obtained by the body not from food, but through the hydrolysis of its own proteins (this dissimilatory process is called protein reutilization).
Energy function is measured in kilocalories (kcal) or kilojoules (kJ). According to methodical materials, 1 kJ corresponds to 4.186 kcal.
| Nutrient / Product | Energy value, kcal/g |
|---|---|
| Fats | 9,0 |
| Ethyl alcohol | 7,0 |
| Starch | 4,1 |
| Proteins | 4,0 |
| Carbohydrates | 4,0 |
| Mono- and disaccharides | 3,8 |
| Xylitol, sorbitol | 2,4 |
| Dietary fiber | 0 |
Organic acids also have energy value: lactic acid provides 3.6 kcal, acetic acid — 3.5 kcal, citric acid — 2.5 kcal, malic acid — 2.4 kcal. The exception is tartaric acid, whose energy value is zero.
Briefly: answers to topical questions
Which infectious and parasitic diseases are transmitted alimentarily?
The transmission of the following infectious diseases via the alimentary route is directly indicated in the sources:
- tuberculosis caused by M. bovis;
- viral hepatitis A;
- typhoid fever.
Parasitic diseases transmitted alimentarily are not specified in the cited sources.
What subgroups is bacterial food poisoning divided into?
Bacterial food poisoning is subdivided into three main subgroups.
- Toxicoinfections are diseases caused by opportunistic pathogens.
- Bacterial toxicosis is poisoning caused by microbial toxins.
- Mixed (mixtures) are mixed bacterial food poisonings.
Which microorganisms are the causative agents of food toxicoinfections?
The causative agents of food toxicoinfections are various opportunistic microorganisms.
- Escherichia coli (E. coli) — causes poisoning upon food contamination.
- Proteus bacillus (Proteus) — an opportunistic pathogen.
- Enterococci — belong to the causative agents of toxicoinfections.
- Spore-forming bacteria — also cause these diseases.
- Halophilic vibrios (Vibrio parahaemolyticus) — transmitted via salted vegetables.
Into what groups is non-bacterial food poisoning classified?
Non-bacterial food poisoning is classified into three main groups.
- Poisoning by naturally toxic products — includes poisoning by mushrooms, wild plants, fish, and internal secretion glands of slaughtered animals.
- Poisoning by products that are poisonous under certain conditions.
- Poisoning caused by chemical impurities.
How do foodborne toxic infections differ from bacterial toxicosis?
The main difference lies in the mechanism of development of the pathological process.
| Characteristic | Foodborne toxic infections | Bacterial toxicosis (intoxication) |
|---|---|---|
| Pathogenesis | Caused by the combined action of live pathogens and endotoxins | Caused by microorganism toxins |
| Involvement of living cells | Caused by live pathogens and their toxins | Without the obligatory involvement of living cells in the pathogenesis |
| Toxin example | Endotoxins released upon microbial death | Staphylococcal enterotoxin, which is an exotoxin |
Which chemical substances (xenobiotics) most frequently cause non-bacterial food poisoning?
Non-bacterial food poisoning caused by chemical impurities, according to the sources, includes:
- Pesticides — organochlorine (OCPs) and organophosphorus compounds (OPCs).
- Copper salts — cause poisoning when acidic food is stored in copper cookware with damaged tinning.
- Zinc — poisoning occurs when galvanized cookware is used for food preparation.
To remember the caloric coefficients of the main macronutrients, use the «Four-Nine-Four» formula: Proteins (4) — Fats (9) — Carbohydrates (4).
Class and exam questions
What is the difference between dissimilation and assimilation processes?
Dissimilation is the continuous process of tissue breakdown, which does not depend on food intake. Assimilation is the creation of new cells; it requires energy expenditure and an obligatory intake of plastic substances with food.
What are diseases of improper food combining?
These are diseases (Group IV) arising from the incompatibility of ingested foods. This category includes food allergies, enzymopathies, and enteritis, which can develop, for example, from the simultaneous consumption of milk with fresh cucumbers or herring.
What is the protective-immune function of food?
Food provides proteins, trace elements, and fatty acids that are essential for the production of antibodies against infections, as well as for binding and eliminating chemical toxins (xenobiotics).
What else to study on this topic
- Pathogenesis of bacterial food poisoning
- Mechanisms of xenobiotic detoxification using food components
- Specific enzymopathies and food intolerance
- Prevention of foodborne infectious diseases
- Mechanisms of hypervitaminosis and mineral excess development (fluorosis, siderosis)
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