Analysis of sanitary and epidemiological safety of students' nutrition for the formation of adaptive immunity to alimentary and viral diseases

Eliseeva Lyudmila Gennad'evna Doctor of Technical Science Professor, Department of Commodity Science and Commodity Expertise, Plekhanov Russian University of Economics 117997, Russia, g. Moscow, per. Stremyannyi, 36, aud. 438 Eliseeva.LG@rea.ru Belkin Yurii Dmitrievich PhD in Technical Science Associate Professor, Department of Commodity Science and Commodity Expertise, Plekhanov Russian University of Economics 117997, Russia, g. Moscow, per. Stremyannyi, 36, aud. 438 Belkin.YD@rea.ru Osman Ali Assistant, Department of Commodity Science and Commodity Expertise, Plekhanov Russian University of Economics 117997, Russia, g. Moscow, per. Stremyannyi, 36, aud. 438 Osman.A@rea.ru Molodkina Polina Georgievna Assistant, Department of Commodity Science and Commodity Expertise, Plekhanov Russian University of Economics 117997, Russia, g. Moscow, per. Stremyannyi, 36, aud. 438 Molodkina.PG@rea.ru Makhotina Irina Alekseevna PhD in Technical Science Associate Professor, Department of Commodity Science and Commodity Expertise, Plekhanov Russian University of Economics 117997, Russia, g. Moscow, ul. Stremyannyi Pereulok, 36 irina_mahotina@mail.ru Other publications by this author

Santuryan Tat'yana Arturovna Assistant, Department of Commodity Science and Commodity Expertise, Plekhanov Russian University of Economics 117997, Russia, g. Moscow, per. Stremyannyi, 36, aud. 438 Santuryan.TA@rea.ru

The Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) have identified two of the most pressing problems that pose a potential threat to the safety of life and health of the world's population – inadequate nutrition in all forms of manifestation, which does not correspond to modern scientific foundations of nutritionology and the problems of food raw materials and food safety caused by the ecological crisis on the planet. The problem of safety, food quality and food security are closely related. In this regard, ensuring the safety and quality of food products that meet modern consumption standards to prevent the development of alimentary and infectious food diseases is an important component of the international food security program ^[1,2]. The World Health Organization has determined that in order to solve the most important problems in ensuring international food security, it is necessary to ensure access to a sufficient amount of safe and high-quality food not only to maintain the vital activity of the population, but also to prevent the development of non-communicable and infectious diseases, as well as to strengthen health and the formation of adaptive immunity of the population, this is an international problem and all countries they suffer from various forms of its manifestation ^[3].

The UN Committee on Economic, Social and Cultural Rights considers it necessary to ensure the right of the world's population to adequate nutrition, which implies: "The availability of food, the quantity and quality of which is sufficient to meet the needs of people in a diet free of harmful substances and acceptable for this culture; access to such food should be carried out in sustainable ways and not hinder the realization of other human rights" and obliges the governments of all countries to ensure access to high-grade and safe food products, to combat malnutrition in all its forms ^[4]. Currently, more than 30% of the population face various forms of violation of the recommended nutritional structure. According to FAO/WHO, safe, balanced and nutritious nutrition plays an important preventive role in the prevention of alimentary diseases, including obesity, cerebral circulatory disorders, diabetes mellitus, cardiovascular and oncological diseases, which are closely related to the lack of functional macro- and micronutrients in the diet.

The costs of rehabilitation of patients in the world are approaching $ 4 trillion. Malnutrition is one of the ten most important risk factors for the active spread of alimentary food diseases in the world, causing an increase in the costs of states for their treatment. The urbanization of the population, environmental, economic and demographic reasons lead to a decrease in soil fertility and depletion of the potentially possible nutrient content in agricultural products. The resolution of the II FAO/WHO International Conference on Nutrition states that modern international food systems in an unstable model of production and consumption cannot cope with the task of supplying the population with the necessary amount of full-fledged, balanced in nutritional and physiological value of food to ensure a safe nutritional status that meets the requirements of healthy nutrition standards ^[5,6].

A large role was given to the nutritional diet of the population by specialists in the field of food hygiene in connection with the spread of the epidemic of coronavirus infection. Experts from all over the world have integrated their efforts to ensure the safety of the population and prevent the spread of the COVID-19 epidemic. Along with the development of treatment methods for coronavirus infection, much attention is paid to improving the adaptive resistance of the body to prevent the disease. WHO analyzed the opinion of scientists around the world and came to the conclusion about the important role of nutrition structure in the formation of protective mechanisms of the body's resistance to negative biotic and abiotic factors. In this regard, the correction of nutrition to eliminate the deficiency of functional macro- and micronutrients is an important element of the formation of adaptive immunity for the prevention of the disease. Nutritionists from all leading countries of the world have conducted comprehensive large-scale studies to study the impact of nutrition structure on the possibility of preventing coronavirus and have identified the most important functional ingredients that have a positive effect on increasing resistance to the disease and contributing to the successful treatment of sick people. Based on the results of these studies, the Food and Agriculture Organization of the United Nations (FAO) and WHO have developed recommendations for optimizing the diet at the stages of preventive work with patients and in the treatment of COVID-19 coronavirus infection, aimed at reducing the systemic inflammatory response of the body and correcting the metabolic response of the body to viral invasion ^[7,8]. Based on international recommendations, national programs are being developed on the recommended nutrition structure for correcting the body's metabolic response to COVID-19. In Russia, the FITZ of Nutrition and Biotechnology and Rospotrebnadzor have developed a guide "COVID-19: rehabilitation and nutrition" containing recommendations for ensuring the safety of the population during the epidemic of viral diseases and providing the population with therapeutic nutrition aimed at correcting the deficiency of vitamins, trace elements and other micronutrients of nutrition to increase adaptive potential ^[9,10]. It is proved that immune cells are highly sensitive to the nutrient composition of food and in this regard, this factor is used in medical practice to form and maintain adaptive immunity and immune resistance to infectious diseases. The nutritional status is recommended to be used as an indicator that ensures the safety of the population and resistance to coronavirus infection. An important direction in ensuring the safety of the population during the epidemic is monitoring the availability of adequate intake of nutrients with immunomodulatory properties. A number of amino acids have confirmed immunomodulatory properties, including sulfur–containing amino acids, taurine, arginine, glutamine; ? - 3 polyunsaturated fatty acids; vitamin D; mineral elements (Se, Fe, Cu, and Zn) and other substances. Protein and energy deficiency causes a decrease in immunity and resistance to oncological and viral diseases ^[11,12,13]. The need to control and regulate the content of nutrients for the formation of the immune status has been established. The recommended standards are presented in table 1.

Table 1 – Recommended doses of the most important immunomodulators in the daily diet for the prevention of COVID-19 ^[10]

The results of regular monitoring of the provision of the Russian population with the necessary functional ingredients in the nutritional status indicate the insufficiency of these elements in the average diet, which is a risk factor in ensuring food safety and the level of resistance to viral diseases ^[14,15,16].

WHO has expressed concern about the increasing level of the disease among young people, especially students, in recent years. Over the past 15 years, the incidence of students has increased by almost 40%. This is due to an increase in educational, informational, physical activity, psycho-emotional stress, a decrease in the material security of many students, which is accompanied by a violation of eating behavior and rest regime. Students belong to a special category of the population experiencing constant psychological and physical risks. WHO emphasizes that the consolidation of metabolic resistance to adverse abiotic factors plays a great role in the formation of psychological resistance to stress. At the same time, great importance is given to providing the body with physiologically active nutrients, without which it is impossible to create protective reactions. A balanced nutrition structure forms the necessary quality and safety of life of a young organism, immune resistance during periods of increased mental and psychological stress, provides rapid recovery of plastic and energy needs ^[17,18]. In this regard, the study of students' eating behavior during the period of widespread COVID-19 diseases in order to determine the necessary directions for its effective correction for the formation of resistance of young people to viral and alimentary diseases is an integral component of ensuring food security and motivation of a healthy nutrition system ^{[19, 20]}

The purpose of this work was to determine the quality and safety of the students' diet to assess the potential immune status and resistance to coronavirus infection and nutritional nutritional diseases and to develop proposals for targeted correction of students' eating behavior.

To assess the nutritional status, students of an economic university located in Moscow (n=200) were selected.

The following research methods were used in the work. The analytical method was used to analyze foreign and domestic literature sources in the field of ensuring international food security, the influence of nutrition structure on the development of nutritional and infectious diseases, substantiation of the composition and quantity of necessary immunomodulating nutrients for the formation of the adaptive potential of the body. The paper uses the method of questioning students to find out the necessary level of satisfaction of the body with immunomodulating food ingredients to ensure resistance to coronavirus disease in accordance with international and national recommendations for healthy and preventive nutrition. The questionnaire is an important tool for conducting a sociological survey, on the basis of which an act of analysis of respondents' responses is compiled using classification and grouping methods, generalization and analysis of statistically processed results of answers to questions regarding eating behavior is carried out. The survey was conducted using the method of an individual written selective online survey of 200 2nd year students of two faculties. To conduct an online survey, 30 questions were compiled, reflected in the questionnaire in the form of closed and open questions. The students were provided with remote access to the questionnaire using Google's application – Google Forms - for online questioning and statistical processing, which allows them to systematize and statistically process students' responses regarding their accepted eating behavior. Based on the results obtained, the individual responses of students were analyzed, the results were summarized and the analysis of the compliance of the nutrition structure with the requirements of the established norms of physiological needs and the requirements for the content of physiologically active components responsible for the formation of immune resistance to coronavirus infection was carried out.

A representative group of students was represented by boys (40%) and girls (60%) aged 18-24 years. The distribution of students who took part in the survey is shown in Fig.1, the main contingent (70%) is represented by students aged 20 years. To ensure food safety, the structure of the diet and the mode of eating during the day plays an important role. 5 meals are recommended, while the daily distribution of food consumed is: breakfast 25%, second breakfast - 5%, lunch - 35%, afternoon tea - 10% and dinner 25% ^{[10, p.109]}.

Figure 1. Distribution of the surveyed students by age (n=200)

The distribution of ratings in the survey on the structure of students' nutrition showed that 53% of respondents prefer to eat at least three times a day, about 26% do not have breakfast in the morning, more than 67% use 2-3 snacks between main meals, preferably use fast food, flour, confectionery with different drinks. With two meals a day, the breaks between meals can exceed 5-6 hours. The main amount of food taken by more than 50% of students falls on dinner. The dinner time is variable, varies in a wide range of time from 18 to 22 hours.

During the survey, students were familiarized with the basic requirements for healthy and preventive nutrition. Only personal awareness of the importance of including essential functional ingredients in the diet in the necessary quantities corresponding to the recommended daily intake dose ^{[10, p. 67]} will allow to form resistance to coronavirus infection. Figure 2 presents information describing the attention students pay to the implementation of the rules of rational nutrition.

Figure 2. Students' awareness of the need for proper eating behavior 

Only 30.1% of students understand the importance of a safe and healthy diet in the formation of the necessary immune status to ensure resistance to COVID-19 disease. 41.3% sometimes pay attention to a healthy diet. Consequently, most students do not understand the importance of nutrition structure in the prevention of alimentary and infectious diseases. In this regard, great importance should be given to the assessment of students' eating behavior (Fig.3).

Figure 3. Characteristics of students' eating behavior

In accordance with the established norms of consumption, the physiological need for protein ranges from 60 to 114 g / day, depending on the gender and age of the consumer. The main sources of high-grade protein are meat, fish products and dairy products. In accordance with the approved rational norms of food consumption that meet modern requirements of healthy nutrition, the consumption rate of meat and meat products is 73 kg/year (200 g/ day) and fish and fish products - 22 kg/ year (60 g/ day), milk and dairy products - 50 kg/year (140 g/ day).

Analyzing the level of consumption of basic protein products by students (Table 2), it can be seen that 26.9% of students consume up to 50 g of meat per day and 37.1% - up to 100 g / day, 6% - do not use meat in their diet. At the same time, 4% of respondents answered that they use meat 1 time a week, 13% - 2 times a week, 12% - 3 times a week, 27% - 4 times a week and 44% - daily.

A similar dependence was revealed when analyzing the consumption of fish and fish products. 7% of students do not eat fish and seafood, 39.5% on average use 50 g /day and 36.3% - up to 100 g/day. The level of consumption of milk and fermented milk products on average is 80-100 g per student.

Table 2 – Distribution of respondents by the level of consumption of basic protein products, %

Table 3 shows the recommended daily intake of essential nutrients during the period of increased risk of coronavirus infection

Table 3 - Chemical composition and energy value of standard diets for patients with C0VID-19 ^[10]

The daily dose of protein recommended by the Ministry of Health of Russia in a standard diet should be 85-90 g. Given that the bulk of the surveyed students consume up to 100 g of meat and meat products per day and up to 50 g of fish and seafood and about 100 g of milk and fermented milk products, which are the main sources of full-fledged proteins, it can be concluded that their daily diet it contains about 50-55 g of protein, which is 60-65% of the recommended intake.

Essential fatty acids are an important element that forms the immune status and food safety. The main sources of omega-3 polyunsaturated fatty acids and vitamin D are fatty fish and seafood, to a lesser extent meat products and dairy products. Based on the survey results, it can be concluded that the level of consumption of these products cannot fill the daily need for omega-3 polyunsaturated fatty acids and vitamin D for more than 50% of students. Consequently, the lack of these foods in the diet forms a deficiency in students of the most important immunomodulators of full-fledged proteins, ?-3 polyunsaturated fatty acids and vitamin D, which provide resistance to infectious diseases.

Fruits and vegetables are essential sources of vitamins, minerals, antioxidants, dietary fiber and bioflavonoids, which are necessary for the modulation and maintenance of immunity. It has been scientifically proven that the lack of vitamins D, A, E, C, group B and minerals, especially Zn, Se and Fe, causes a danger of lowering the immune status and reducing resistance to viral infections. Recommended consumption rates of vegetables are 140 kg / year per person (385 g / day), and fruits – 100 kg / year (274 g / day).

About 60% of students use vegetables in their daily diet, and only 30.8% include fruits in their daily diet (Fig. 4).

Figure 4. Distribution of estimates of the frequency of use of vegetables and fruits in the diet

The average amount of vegetable consumption by one student is 100-250 g per day. The average value of the amount of fruit in the diet of one student is 100-150 g in winter and 150-200 g in spring and summer.

Based on the analysis of the students' eating behavior in all the studied areas of providing the diet with a physiologically justified amount of functional ingredients, a deficiency of high-grade protein, dietary fiber, minerals (Zn, Se, Fe), vitamin D was established.

In the current situation, the students' eating behavior requires significant adjustments. In the diet of students during the exacerbation of the epidemic of viral diseases, it is necessary to include biologically active additives, including vitamin and mineral complexes. When interviewing students about the use of vitamin preparations for the prevention of diseases and ensuring the safety of life, 62.9% replied that they use vitamin preparations, of which 36% take vitamins on the recommendation of a doctor and 64% - on their own initiative for the prevention of diseases and ensuring the safety of life (Fig. 5). 34.3% of the surveyed students use them on a daily basis on a monthly basis, 11.2% use the same amount once every six months, the least respondents chose the answer "once a year". The answer "other" was chosen by 6% of respondents, and most of them indicated taking vitamins in certain seasons.

Figure 5. Distribution of estimates of the frequency of intake of vitamin preparations by students

The structure of the composition of vitamins and minerals that students take is shown in Fig. 6. The survey showed students' awareness of the need to use vitamin and mineral complexes to ensure health safety and normal functioning of the body. Most often, students additionally take vitamins C and D. Less attention is paid to meeting the body's needs for minerals and omega 3 polyunsaturated fatty acids.

Figure 6. Frequency series of the distribution of grades according to the structure of vitamins and minerals taken by students

Studies have shown that many students change their eating behavior while studying at the university. The diet changes, the recommended frequency of meals is violated. The ratios of food intake recommended by the Ministry of Health during the day are not observed, the period of taking the main amount of food from breakfast and lunch to dinner is shifted, especially serious eating disorders are noted for nonresident students. There were significant violations in the ratio of intake of the main macro- and micronutrients. In the diet, there are significant violations in the intake of basic protein products, including meat products, fish and seafood and dairy products, an excess of flour and confectionery products, which leads to a deficiency of protein and other important physiologically active nutrients in the diet of 40-50% of students. A characteristic feature of the students' eating behavior is an unbalanced diet, characterized by a deficiency of full-fledged proteins, essential omega-3 fatty acids, vitamin D, zinc and selenium with an excess of carbohydrates, including fast-digested, fast food and products that are classified as "food garbage". The eating behavior of students differs significantly from other groups of the population, it is caused by a high degree of mobility, employment, a wide range of interests, lack of free time and in this regard is accompanied by a high level of stress and psychological stress, especially during sessions. During the study period, students pay little attention to balanced and safe nutrition, regularity of meals, are irresponsible about the frequent use of fast food in nutrition, this is due to lack of time for food and insufficient knowledge in the field of healthy nutrition. In accordance with the developed international recommendations in the field of ensuring high-quality and safe nutrition, it is necessary to educate students in the field of food safety and the formation of eating behavior, taking into account scientifically based requirements for a healthy diet and a healthy lifestyle of students. High-quality and safe nutrition of students is a fundamental component of a healthy lifestyle system.

Based on the analysis of the students' eating behavior, serious violations of the balance of nutrients in the daily and weekly diet of 200 students were established. In this regard, it is necessary to carry out qualitative and quantitative correction of the diet of students to ensure the formation of the necessary immune status for the prevention of infectious and alimentary diseases. To ensure high-quality and safe nutrition, it is necessary to scientifically substantiate and put into practice the students' life activity algorithm for creating a healthy diet to maintain the optimal level of the adaptive immune system, taking into account the complementary complex value to ensure the necessary physiological activity and immune status of the body of the recommended quantitative and qualitative composition of foods that provide the content of full-fledged proteins, omega-3 unsaturated fatty acids, vitamin and mineral complex, including vitamins D,C, E, B, Zn, Se, Fe and other micronutrients in quantities that provide daily physiological needs. Based on the results of the survey of students, it is necessary to recommend the mandatory inclusion in the diet in accordance with the recommendations of WHO and the Ministry of Health of Russia of the following foods: bread made from a mixture of rye and wheat flour or with the addition of whole grain flour or bran, grain loaves; it is necessary to increase the volume of daily consumption of milk and dairy products, including fermented milk and it is necessary to compensate for the lack of daily intake of high-grade protein by increasing the frequency of consumption of meat, poultry and fish and seafood (at least 2 times a week), eggs (2-3 times a week), it is necessary to ensure sufficient content in the diet of fruits and vegetables fresh and after cooking, the daily dose of which should be at least 400 g per day. During sessions, increased physical and psychological stress, during epidemics of viral diseases, it is necessary to include vitamin and mineral complexes or biologically active food additives in the diet to compensate for the lack of the above physiologically active nutrients.