The oral microbiome in the context of systemic disease
The oral microbiome is a community of symbiotic, commensal and opportunistic microorganisms, usually present in the form of biofilm, that plays a critical role in maintaining the homeostasis and protective function of the oral cavity. Recently, the study of the human oral microbiome to develop new diagnostic and therapeutic approaches has become a promising new area of the research in the field of personalized medicine.
The aim of this review was to generalise and analyse the accumulated data on the relationship between the oral microbiome characteristics and the course of systemic diseases.
Material and methods. Literature searches were performed using RSCI, PubMed, Google Scholar, and included original research data published mainly in the last 5 years.
Results. The review summarized data on the role of the oral microbiome in the development of a number of systemic diseases, including alimentary diseases. The importance of the major exogenous and endogenous factors that lead to changes in the oral microbiome, including diet, macro- and micronutrient composition of foods, was highlighted. Data were provided on the main types of microorganisms associated with the development and course of a number of somatic diseases, represented mainly by obligate anaerobic periodontal pathogens (Tannerella forsythia, Treponema denticola, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans). The role of the systemic inflammatory response as the main pathogenetic factor of oral dysbiosis has been described. The benefits of periodontal therapy in metabolic disorders such as diabetes mellitus, obesity, and dyslipidemia have been discussed. Promising approaches to correct oral dysbiosis have been presented.
Conclusion. The knowledge of the relationships between the oral microbiome composition, the development and characteristics of the course of somatic disease can contribute to the development of new technologies for its prevention and treatment. The change in the structure of the oral microbiome observed in systemic diseases is usually accompanied by a decrease in bacterial diversity and an increase in the number of pathogenic bacteria. Lifestyle modification, dietary therapy, smoking cessation, rational use of antibacterial drugs and treatment of periodontitis play an important role in normalising the structure of the oral microbiome.
The role of phytates in human nutrition
Claims that consumption of phytate-rich grains, by definition, worsens mineral status needs to be clarified as new evidence emerges about the role of phytic acids (FA) from whole grains in improving population health outcomes. In this regard, it seems appropriate to draw the attention of practitioners to the need to correct patient’s diet in order to prevent non-communicable diseases.
The aim of this review was to generalize and analyze the modern data on the role of phytates in human nutrition.
Material and methods. A search for domestic and foreign literature in the bibliographic databases of articles on medical sciences was carried out using the PubMed, MEDLINE and eLibrary search engines.
Results. Deficit of minerals and trace elements in the diet, especially deficiency of iron, calcium, selenium, zinc, iodine, is an urgent public health problem in many countries. Calcium, magnesium, zinc, selenium, and iron deficiencies are associated with impaired immune function and an increased risk of both acute and chronic diseases. Vegan and vegetarian behavior styles with the restriction and exclusion of animal sources of bioavailable minerals and trace elements are gaining more and more popularity in our country. FA is the main storage form of phosphorus in nuts, grains, legumes, and seeds, which satisfies the biosynthesis needs of growing tissues during germination. FA is known as a dietary inhibitor that chelates minerals and trace elements, limiting their bioavailability and reducing their absorption. Pre-treatment methods to reduce phytate levels and increase the nutritional value of diets are fermentation, soaking, and sprouting. Reducing phytate content in plant foods by processing leads to a measurable improvement in mineral status, however, the chelating and antioxidant properties of phytates may be beneficial and their potential in the prevention of cancer, cardiovascular disease, diabetes mellitus and kidney stone formation is currently being studied.
Conclusion. Essential components of a healthy diet are whole whole grains, legumes, vegetables, seeds and nuts, despite the fact that most of them are relatively high in FA. Despite some antinutrient properties, FAs have preventive effects on public health.
Assessing of iodine consumption with iodized salt in organized nutrition of children of preschool and school age in the Tyumen region
The territory of the Tyumen region is an endemic region with insufficient iodine content in the environment, in which, since the early 1990s, active preventive measures have been taken to increase the use of iodized salt (IS) in households, catering and the food industry.
The purpose of the research was to assess the consumption of iodine with IS used in the organized nutrition of children in the Tyumen region.
Material and methods. The assessment of iodine intake was carried out in preschool institutions and schools randomly selected the city of Tyumen and rural areas (village of Isetskoye). Modeling of iodine consumption in organized groups was carried out for children aged 1–3, 3–7, 7–11 and 12 years and older in urban and rural areas, respectively, using a standard menu and a technological map of dishes. Iodine intake was estimated based on the content of 40 μg of iodine in 1 g of salt and its 30% loss during cooking. Model 1 assumed the mandatory use of IS in the preparation of all salt-containing meals for preschoolers and schoolchildren. Model 2, in addition to the mandatory use of IS in school and preschool meals accounted the consumption of iodine with bakery products (BP) produced with IS.
Results. The modeling showed that the average intake of iodine with meals (model 1) in preschool institutions in Tyumen was 89±16 µg/day for children aged 1–3 years. When BP with IS were included in the menu (model 2), iodine intake increased to 101±14 µg/day. In children aged 4–7 years iodine intake was 115±18 and 126±18 µg/day, respectively. In rural areas, iodine intake was lower: in children aged 1–3 years, under model 1, iodine intake was 66±3 µg/day, under model 2 – 76±4 µg/day. In children aged 4–7 years, these figures were 83±3 and 92±4 µg/day, respectively. Iodine consumption in a school in Tyumen under model 1 in children 7–11 years old was 24±5 µg/day, and in children 12 years and older – 27±6 µg/day. When BP with IS were included in the menu (model 2), iodine intake increased to 32±5 µg/day in children 7–11 years old and to 39±6 µg/day in children 12 years of age and older. In rural areas, when using model 1, iodine intake in children aged 7–11 years was 37±15 µg/day, in children aged 12 and over 40±21 µg/day. When BP with IS were included in the menu (model 2), iodine intake increased to 44±15 µg/day in children aged 7–11 years and to 50±21 µg/day in children 12 years of age and older.
Conclusion. The use of IS in the preparation of salt-containing meals in preschool educational institutions of the Tyumen region fully covered the iodine requirements of preschool children, which confirms the effectiveness of the chosen strategy for the prevention of iodine deficiency and can be considered as an important part of the concept of universal salt iodization. The use of IS in preparation of school breakfast meals provides 23.5–36.9% of the recommended nutrient intake for iodine in rural schools and 15.4–26.4% of the recommended nutrient intake in urban schools, which can be a significant contribution to the total intake of this micronutrient.
Health risk assessment associated with priority potentially hazardous chemical compounds detected in canned meat and meat-and-vegetable food for infants
Assessment of public health safety associated with chemical contaminants consumed with food is an important component for solving the tasks of ensuring the sanitary and epidemiological well-being of the population. For these purposes, it is necessary to establish priority potentially dangerous compounds among the identified undeclared and unintended chemical contaminants for further consumers risk assessment. In conditions of unacceptable levels of health risk, it is necessary to decide whether it is advisable to develop new or change existing hygiene standards for these substances.
The aim of the study was to assess the health risk associated with priority potentially dangerous unintended chemical components of contamination in canned meat and meat-and-vegetable products for infants (using the example of N-nitrosoamines).
Material and methods. The selection of priority chemical compounds and public health risk assessment were carried out in accordance with the procedure for identifying undeclared and potentially dangerous unintended chemicals in food and using modified approaches based on the results of previous studies. Health risk assessment for infants consuming canned meat and meat-and-vegetables containing priority chemicals was carried out in accordance with the methodology approved by the Eurasian Economic Commitee, as well as using the Guidelines for assessing risks to public health when exposed to environmental pollutants. To characterize the calculated risk levels, the classification proposed in the draft document «Guidelines for assessing risks to public health when exposed to environmental pollutants» was used.
Results. N-nitrosoamines are classified as chemical contaminants that are a priority for public health risk assessment, identified on the basis of the potential hazard category. A comparative health risk assessment for the target group consumers of canned meat and meat-and-vegetables sold on the territory of the Russian Federation and the Socialistic Republic of Vietnam showed the presence of an unacceptable risk to the health of the Russian population in relation to non-carcinogenic adverse health effects associated with the intake of N-nitrosodimethylamine (NDMA) (hazard quotient HQ=1.1) and N-nitrosodibuthylamine (HQ=5.25). Many experimental (animal) researches confirm the formation of negative effects and potential harm to humans, formed by the consumption of N-nitrosoamines with food. At the same time, the level of the exposure of N-nitrosoamines during oral administration was assessed mainly from the side of carcinogenic effects, however, this study reflects the hazard, including from non-carcinogenic risks associated not only with NDMA and N-nitrosodiethylamine, for which there is a hygienic standard, but also for other N-nitrosoamines, for which there is no hygienic regulation. In turn, the European Food Safety Agency’s (EFSA) study notes that it is necessary to conduct a risk assessment for human health in relation to other N-nitrosoamines identified in food, and, if necessary, rationing of these compounds, which is also confirmed by this study.
Conclusion. The conducted health risk assessment of the target population of Russia (infants from 6 months to 3 years) consuming the studied types of products containing N-nitrosoamines showed the presence of unacceptable levels of non-carcinogenic health risks in relation to the development processes and impaired liver function. In connection with the identified risks to the health of the target population, it is advisable to establish maximum permissible levels not only for the amount of NDMA and N-nitrosodiethylamine, but also for other N-nitrozoamines identified by the results of the study, with their subsequent regulation.
Actual nutrition in adults with familial hypercholesterolemia
Familial hypercholesterolemia (FH) is a highly atherogenic, genetically based lipid disorder. For patients with FH, dietary modification is the cornerstone of complex lipid-lowering therapy.
The aim of the research was to assess the actual nutrition in adults with familial hypercholesterolemia.
Material and methods. The study included 100 patients over 18 years old (including 46% men) with “probable” or “definite” FH according to the Dutch Lipid Clinic Network or Simon Broome criteria from the GENMOTIV-FH study (ClinicalTrials: NCT04656028) in 2019–2021. Actual nutrition was assessed using the 24-hour dietary recall method. The frequency of the main meal groups’ consumption and food-related behavior were assessed using a questionnaire method. The data are presented as the median [Q25; Q75].
Results. The study showed the excess consumption of protein (19.3 [16.7; 24.0] in men and 18.6% [13.6; 24.3] in women, p=0.592), total fat (35.1 [29.4; 41.0] in men vs 39.2% [33.2; 47.5] in women, p=0.018), including saturated fatty acids (9.6 [4.7; 13.0] vs 10.4% [7.5; 14.2], respectively, p=0.151), and cholesterol (265.8 [188.8; 521.9] mg/day in men vs 282.1 [147.2; 542.8] mg/day in women, p=0.936). Consumption of total carbohydrates (44.3 [37.2; 50.0] vs 39.6% [30.1; 48.8], respectively, p=0.100) and fiber (10.7 [7.3; 13.3] g/day in men vs 11.5 [7.9; 13.9] g/day in women, p=0.372) was insufficient. Only 47.9% of patients consumed vegetables daily, 39.1% – fruits and berries. The majority (64.5%) of patients with FH preferred high-fat cheese (≥25%). Cottage cheese of ≥5% fat content preferred 52.7% of patients. The daily poultry consumption was more than red meat (19.3 vs 4.3% respectively, p=0.003). Regularly included fish in their meal 53.8% of patients.
Conclusion. The actual nutrition in adults with FH does not match international guidelines. The results highlight the importance of dietary interventions for patients with FH.
Justification of the need to introduce an additional criterion to the assessment of the nutrition status of military personnel
Currently, in accordance with the regulations of the Government of the Russian Federation and the Ministry of Defense of the Russian Federation, the main indicator for assessing nutritional status is the body mass index, which does not take into account the component composition of the body. At the same time, it is necessary to assess in more detail the composition of the body of military personnel, that is, the ratio of its muscle and fat components.
The purpose of the study is the scientific and methodological substantiation of the need to introduce an additional criterion for assessing the nutritional status of military personnel, that characterize body composition – the body fat percentage.
Material and methods. The study involved 1.373 male military personnel aged 18 to 53 who underwent a medical examination. The following methods were used: anthropometry, bioimpedancemetry, caliperometry.
Results. Various methods for determining the fat component of the body have been studied. The analysis of the data obtained showed that all methods for determining the body fat percentage have highly significant correlations among themselves and with bioimpedancemetry data. All coefficients had high reliability p<0.001 at r>0.7. When the values of the body mass index deviate from the normative ones, it is proposed to use the indicator of the body fat percentage to clarify the assessment of the nutritional status of male military personnel. Based on the data obtained, modern algorithms for assessing the nutritional status of military personnel have been developed for use in the practice of military health care at various levels of medical support for military personnel.
Conclusion. As a result of a prospective study, the need to introduce an additional criterion for assessing the nutritional status of male military personnel was substantiated and proved, and calculation methods for assessing the fat component of the body, comparable with bioimpedancemetry data, were determined. Algorithms for determining the nutritional status of servicemen for different levels of medical support have been developed. In conditions where special devices for determining the fat component of the body are not included in the supply standards of the medical service, it is recommended to calculate the body fat percentage by girth methods using a centimeter tape.
Relationship of vitamin A and thyroid function in Arctic residents
At the present time the prevalence of thyroid diseases keeps growing, so knowledge of the factors affecting thyroid activity is very important. Vitamin A (retinol) is a fat-soluble vitamin with a hormone-like effect that can influence both the expression of thyroid-stimulating hormone in the pituitary gland and the synthesis of thyroid hormones.
The aim of the research was to study vitamin A serum level and its relationship with the thyroid profile in residents of the Arctic zone of the Russian Federation, depending on gender.
Material and methods. In the course of a single-center observational cross-sectional study, 304 apparently healthy residents of villages in the Arkhangelsk region (103 men and 201 women) were examined. The serum concentration of vitamin A was determined by the fluorometric method, and the content of thyroid parameters was determined by the enzyme immunoassay. The integral thyroid index (ITI) and the index of peripheral conversion of iodothyronines (IPC) were calculated. The subjects were divided into 4 groups depending on the quartile of vitamin A. The relative risk of developing subclinical hypothyroidism was calculated with a reduced concentration of vitamin A.
Results. The content of vitamin A was 1.97 (1.18; 2.97) µmol/l. Retinol levels in the female population were significantly lower than in the male population (1.85 vs 2.27 µmol/l, p<0.0001). Women in group 1 compared with group 4 showed significantly higher levels of thyrotropin (2.33 vs 1.40 μIU/ml, p=0.0002) and thyroxin (109.8 vs 99.4 nmol/l, p=0.010), while the ITI values, on the contrary, were the lowest (8.12 and 13.85 c.u., p=0.0002). The relative risk calculation showed that vitamin A levels below 1.39 µmol/L increase the risk of subclinical hypothyroidism in women by 2.01 times [95% confidence interval 1.07–3.78]. Men in group 4 compared with group 1 showed a lower content of thyroxin (83.0 vs 109.2 nmol/l, p=0.009) against the background of higher IPC values (0.019 vs 0.016 c.u., p=0.046).
Conclusion. In the inhabitants of the Arctic, the content of vitamin A is within the reference values, however, in 24.3% of men, its level is above the norm. In women, the concentration of retinol is significantly lower, and its level of less than 1.39 µmol/l increases the risk of developing subclinical hypothyroidism by 2.0 times. Increased values of vitamin A in the inhabitants of the North cause lower levels of thyroxine and an increase in the peripheral conversion of iodothyronines, which is more pronounced in men.
In vivo study of the biological value of amaranth protein concentrate and its module with chicken egg protein
Amaranth (Amaranthus L.), like other pseudocereals as quinoa (Chenopodium quinoa Willd.), chia (Salvia hispanica L.) and buckwheat (Fagopyrum sp.), is a promising source of dietary protein. Depending on the subspecies and breeds of amaranth, the protein content in its grain is estimated from 13.1 to 21.5%, and its amino acid score varies over a significant range and can be limited.
The aim of this study was to obtain a protein concentrate from amaranth (Amaranthus L.) grain of the Voronezh breed, enrich it with chicken egg protein, determine the amino acid score of the obtained protein module, and experimentally evaluate in vivo its true digestibility and biological value.
Material and methods. The amaranth protein concentrate was obtained from grain according to the technological scheme, including its enzymatic treatment, alkaline extraction, acid precipitation of proteins, microfiltration and lyophilization. The amino acid composition and amino acid score of the concentrate were determined. The protein module was obtained by mixing amaranth protein concentrate and chicken egg protein in a weight ratio of 58:42. The true digestibility and biological value of the protein module has been determined in vivo. The experiment was carried out on 32 Wistar male rats divided into 2 groups (n=16 rats): control group 1 with a body weight of 118.7±3.1 g and experimental group 2 with a body weight of 119.5±3.0 g. Animals of groups 1 and 2 received diets in which egg protein and a protein module were used as a protein source, respectively. Within 15 days of the experiment, individual indicators of food intake and body weight gain of each animal were determined. From the 14th to the 15th day food intake was determined and feces were collected. The amount of nitrogen in the food and feces was determined for each rat using the Kjeldahl method. The true digestibility of the protein was determined according to obtained data.
Results. The resulting amaranth protein concentrate contained 70.4±0.6% of protein, 17.0±1.0% fat, 9.8±0.8% carbohydrates, 1.8±0.2% ash, its moisture content was 1.4±0.1%. There were no significant differences in food intake and body weight gain between animals of both groups. The calculated value of the true digestibility of chicken egg protein was 98.8±0.1% for the control group 1,of the protein module was 99.0±0.1% for the experimental group 2, the differences between the groups were not significant.
Conclusion. The results of amino acid analysis and the in vivo study of the true digestibility of the protein module (composition amaranth protein/chicken egg protein) indicate the absence of limitation relative to the amino acid scale of the “ideal” protein (FAO/WHO, 2007) and high true digestibility. The biological value of the protein module, calculated according to PDCAAS, is 99.0±0.1%, which confirms the prospects for its inclusion in specialized foods.
Effects of triterpenoids in fatty products on liver condition of laboratory animals with acute toxic hepatitis
One of the principles of prevention and non-medicamentous treatment of liver diseases, including hepatitis of different etiology, is the normalization of the diet through the consumption of food with physiologically active ingredients, in particular betulin, which helps to eliminate the causes of metabolic and oxidative disorders within liver cells.
The aim of the research was to assess in vivo the influence of triterpene alcohol betulin extracted from Betula pendula Roth. birch bark in fat-containing products (for example mayonnaise) on the blood biochemical parameters and liver morphological structure of rats with initiated acute toxic hepatitis.
Material and methods. Hepatoprotective and antioxidant activities of betulin as part of mayonnaise samples has been investigated in vivo on the model of toxic hepatitis initiated by carbon tetrachloride in male Wistar rats weighing 210–265 g. The animals were divided into 4 groups of 10 animals each: CG-1 – intact, CG-2 and MG – with carbon tetrachloride initiated toxic hepatitis. rats of the main groups were orally administered mayonnaise once a day at a dosage of 1 ml for 21 days after the formation of the model pathology: OG-1 with the added betulin (1 mg per 1 kg of body weight), OG-2 without betulin. Disorders of metabolic and oxidative processes in liver cells of animals were evaluated by biochemical indicators of blood plasma: the level of glucose, albumin, total cholesterol, triglycerides and urea and the activity of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ-glutamyltransferase. Oxidative stress in rats was estimated by the activity of catalase and superoxide dismutase in blood hemolysate (at a dilution of 1:200 and 1:10, respectively); the total prooxidant (in blood plasma) and total antioxidant (in blood hemolysate at a dilution of 1:10) activity were determined spectrophotometrically (colored complexes of TWIN-80 oxidation products with thiobarbituric acid). The morphological structure of rats’ liver was estimated by microscopy of prepared cuts of hepatic tissue.
Results. Based on biochemical parameters of rat blood plasma, it has been established that the administration of mayonnaise with betulin prevents the development of cytolic syndrome and suppresses the process of peroxidation by directly neutralizing free radicals. Aspartate aminotransferase and alkaline phosphatase activity in blood plasma of the experimental animals of the main group MG-1 reduced by 20.7 and 35.2% compared with indicators of the rats of the main group MG-2. Glucose concentration normalized to the level of the control group CG-1. The concentration of bilirubin and triglycerides decreased by 22.9 and by 48.1%, which indicates a significant reduction in the indicators of cholestatic syndrome in the group of animals OG-1 compared to OG-2. The total prooxidant activity and the concentration of thiobarbiturate-reactive products decreased compared to the CG-2 and MG-2 groups, which indicates the suppression of oxidative stress and, as a result, an improvement in liver conditions of animals with toxic hepatitis even when taking a fat-containing product. In liver histopeparates of animals receiving mayonnaise with betulin, necrobotic changes were less pronounced in comparison with the group MG-2. They were estimated at 1 point: small-drip dystrophy spots were found, haemorrhages in the interregional septum with inflammatory infiltration in the course of hemorrhages against the presence of necrosis hepatocytes with pronounced adipose dystrophy in the centres of the lobules, step necrosis with signs of replacing the damaged hepatocytes of the connective tissue, accompanied by centrolobular hemorrhages in MG-2 rats.
Conclusion. Introduced into the composition of mayonnaise betulin, reduces the development of cytolic syndrome in toxic hepatitis and suppresses the process of peroxidation, on the basis of which fat-containing foods with betulin can be recommended for clinical examination as specialized products in acute and chronic liver diseases, including complicated cholestasis.
Clinical efficacy of a modern probiotic for the correction of intestinal microflora in patients with irritable bowel syndrome with diarrhea and antibiotic-associated diarrhea
Despite the fact that dietary supplements (DS) are not medicines, an increasing number of publications testify to the effectiveness of probiotics consumed with food in the complex treatment and prevention of a number of diseases of the gastrointestinal tract, including irritable bowel syndrome (IBS) and antibiotic-associated diarrhea (AAD).
The purpose of the study was to evaluate the effectiveness of the complex probiotic in the relief of diarrheal syndrome associated with intestinal microbiota dysbiosis in patients with IBS with diarrhea and AAD.
Material and methods. The study included 54 patients (31 with IBS with diarrhea and 23 with idiopathic AAD) aged 18 to 50 years. All patients included in the study were prescribed 1 capsule (350 mg) of the DS Neobiotic Lactobalance® per day for 21 days. One capsule contains: bifidobacteria (Bifidobacterium longum CBT BG7, Bifidobacterium lactis CBT BL3 Bifidobacterium bifidum CBT BF3), lactobacilli (Lactobacillus acidophilus CBT LA1, Lactobacillus rhamnosus CBT LR5), lactic acid bacteria (Streptococcus thermophilus CBT ST3), fructooligosaccharides, vitamin C. The daily intake of bifidobacteria was 8.7×108 CFU, lactobacilli – 6.1×109 CFU, lactic acid bacteria 3.1×108 CFU and vitamin C – 12 mg. The severity of symptoms was assessed in points (from 0 to 7 points) using the GSRS questionnaire (Gastrointestinal Symptom Rating Scale). All patients underwent a microbiological analysis of feces with an assessment of the degree of dysbiosis before and after the administration of DS.
Results. In patients with IBS with diarrhea, the assessment of the manifestations of diarrheal syndrome according to the GSRS questionnaire decreased statistically significantly from 17 to 6 points (2.9 times), abdominal pain – from 12 to 4 points (3.0 times) and dyspeptic syndrome – from 8 to 3 points (in 2.7 times). In patients with AAD, also according to the GSRS questionnaire, the manifestations of diarrheal syndrome decreased statistically significantly from 13 to 3 points (4.3 times), abdominal pain – from 4 to 1 points (4.0 times) and dyspepsia syndrome – from 5 to 2 points (in 2.5 times). Against the background of DS intake, according to the data of bacteriological examination of feces, intestinal microbiota normalized by day 21 due to an increase in the number of lacto- and bifidobacteria (p≤0.05).
Conclusion. The study showed that the DS Neobiotic Lactobalance® contributes to the normalization of the intestinal microbiota and reduces the severity of clinical manifestations (diarrheal disorders or manifestations of diarrhea) in IBS and idiopathic AAD.
Clinical evaluation of the efficacy of innovative spread of a given fatty acid composition enriched by adaptogens
Adaptogens are a group of substances capable to increase the nonspecific resistance of the organism to a wide range of harmful effects and stress. However, only limited data exist on their use in the composition of foods for special dietary uses.
The aim of the study was to evaluate the effect of a diet that included vegetable-fat spread enriched with 5-hydroxytryptophan, L-theanine and γ-aminobutyric acid on memory, general well-being and emotional status of healthy volunteers.
Material and methods. The single-center, single-blind randomized prospective trial that enrolled persons without signs of significant organic pathology have been performed. Participants were randomly allocated to receive either 45 g/day standard spread enriched with 5-hydroxytryptophan (0.67%), L-theanine (0.56%) and γ-aminobutyric acid (0.45%) (main group, MG) or 45 g/day standard spread (control group, CG) for 10 days. Beside this, all participants followed a standard diet. Initially, as well as on the 10th day after the start of using the diet, the emotional state was assessed using the HADS anxiety and depression scale and Beck’s depression inventory (BDI), general well-being by SAN questionnaire, memory according to the Lurie method; reaction time and attention concentration were assessed using the Krepelin counting test and the Burdon correction test. A 5-point Likert visual-analogue scale was used to assess the palatability (pasting) of the product, the severity of feelings of hunger and satiety at the baseline and on the 10th day of the study. All tests were performed under the supervision of staff. During the study, daily monitoring of the presence of adverse events was performed.
Results. There were 70 subjects in MG and 70 in CG. Lurie memory score significantly increased in the MG (59.9±6.7 vs 58.1±7.4 points at the baseline; p=0.001), but not in the CG (58.0±6.9 vs 57.3±7.3 points, p>0.05). According to the SAN questionnaire, significant increase of well-being values (46.9±13.4 vs 44.2±13.5 points; p=0.01) and mood (49.9±12.6 vs 47.4±12.9 points; p=0.01) was found in MG, while in CG there was an increase of the mood category only (54.4±10.8 vs 52.2±12.1, p=0.04). At the end of the study an increase of «Satiety» (60.3±22.8 vs 51.5±24.8, p=0.022) and decrease of «Hunger» score (24.1±19.8 vs 29.1±19.4, p=0.02) were revealed in CG but not in the CG. No significant change was found by the results of other tests, stool form and its frequency in both groups.
Conclusion. Newly developed spread enriched with 5-hydroxytryptophan, L-theanine, γ-aminobutyric acid was well-tolerated, did not affect the feeling of hunger and satiety, and improved memory and well-being parameters.
Protein in the athlete’s diet: rationale for intake levels at different training intensities to maintain lean body mass (a brief review)
Nutrition in sports, as a branch of nutritional science, is a constantly developing field with a growing number of scientific researches and recommendations concerning the justification of the diet composition to ensure the requirements for macro- and micronutrients of the athlete’s body at different stages of sports activity and energy value, as well as the use of special dietary supplements of various nature, including protein in forms of specialized dry mixes, drinks, etc.
The aim of the research was to present the results of studies conducted abroad, presented in review publications and original articles, on the role of protein and the impact of its various levels of consumption on the maintenance of muscle mass as a criterion for the effectiveness of diets used, including in conditions of their reduced calorie content; on the safety of consuming significantly higher than recommended amounts of protein (>2.0 g/kg of body weight per day); about the relationship between protein dose and the possible increase in lean body mass.
Material and methods. For the main source search, the PubMed Internet resource was used, and the websites of the Springer and Elsevier publishers were used to access the full text of the articles. Search depth 10 years.
Results. This review presents the official position of the International Society of Sports Nutrition (ISSN) on the role of protein in training optimization, body composition change and improving the performance of athletes. Generalized data on the body’s energy costs for the assimilation of nutrients, food thermogenesis and the importance of protein for maintaining resting energy expenditure are presented. Published results based on meta-analyses support the efficacy of higher protein intake in reducing body weight and fat mass while maintaining lean mass in an energy-deficient setting. The anabolic properties of protein under conditions of increased physical exertion will manifest themselves only with sufficient energy and protein supply. The proposed values and boundaries within which increased protein intake effectively affect body composition in the process of adaptation to strength training are given. It has been shown that an increase in protein intake above the average maximum values practically does not lead to an increase in lean body mass without the simultaneous introduction of additional resistance exercises that restores its growth. In accordance with the official position of the ISSN, the recommended protein intake corresponds to values from 1.4 to 2.0 g/kg of body weight per day for individuals performing various special sets of physical exercises. The use of high-protein diets (protein >2.0 g/kg/day) in highly qualified athletes who do not have kidney and liver diseases showed no changes in the biochemical parameters of blood and bone mineral density confirming its safety.
Conclusion. Based on the analysis of scientific data, it can be stated that proteins make the main contribution to the thermogenesis of the body compared to other dietary macronutrients. The effect of protein intake on body composition, recovery and muscle building of an athlete has been proven. Athletes require higher amounts of protein to optimal increase of lean body mass under increased training loads and to maintain lean mass under an energy-deficient diet. If necessary, high-protein diets can be used in highly qualified athletes without kidney or liver diseases, but comprehensive researches in this direction should be continued.