Chemical Composition of Vegetables and Diet-dependent Intensity of Caries in Residents of Chervonograd (Ukraine) and Kraśnik (Poland)

Background Nutrition is one of the major determinants of human health. Consuming plant foods provides not only nutrients but also bioactive substances that reduce disease. The health of the oral cavity is determined by the quality of food, including vegetable food. Objective To study the effects of macro and microelements in vegetables on the status of mineralised dental tissues in relation to the hygiene and nutritional habits in 15-year-old adolescents living in Lublin Province and Lviv Oblast. Methods The chemical composition of plants was assessed (macro and microelements) of carrots and potatoes, vegetables consumed by 15-year-old inhabitants of Poland and Ukraine. The status of mineralised dental tissues was assessed based on caries severity expressed by the mean D3MFT number and the SIC index value. Another part of the study was a socio-medical survey focused on assessment of patients' eating habits.The respondents answered questions about the frequency of consumption of fruit and vegetables and fruit juices. The present study showed in vs. 75% in the from Chervonograd. The intensity of measured by the in the teenagers from Chervonograd who everyday of fresh and was 3.77, and from Krasnik 5.17. a good whereas provide potassium The on the which depended An inverse correlation for the of The concentration of both was in of microelements for shown the of as


Abstract Background
Nutrition is one of the major determinants of human health. Consuming plant foods provides not only nutrients but also bioactive substances that reduce disease. The health of the oral cavity is determined by the quality of food, including vegetable food.

Objective
To study the effects of macro and microelements in vegetables on the status of mineralised dental tissues in relation to the hygiene and nutritional habits in 15-year-old adolescents living in Lublin Province and Lviv Oblast.

Methods
The chemical composition of plants was assessed (macro and microelements) of carrots and potatoes, vegetables consumed by 15-year-old inhabitants of Poland and Ukraine. The status of mineralised dental tissues was assessed based on caries severity expressed by the mean D3MFT number and the SIC index value. Another part of the study was a socio-medical survey focused on assessment of patients' eating habits.The respondents answered questions about the frequency of consumption of fruit and vegetables and fruit juices.

Results
The chemical composition of plants depended on the species and place of cultivation. The present study showed higher caries frequency in the group of the 15-year-olds living in Kraśnik, i.e. 88% vs. 75% in the group from Chervonograd. The intensity of caries measured by the mean D3MFT value in the 15-year-old teenagers from Chervonograd who declared everyday consumption of fresh vegetables and fruit was 3.77, and from Krasnik 5.17.

Conclusion
The present results show that carrots are a good source of microelements for humans, whereas potatoes provide potassium and calcium. The impact of the frequency of consuming plant products on the health of the oral cavity, which depended on the place of youth research.

Background
Vegetables and fruit are an important element of human diet and a determinant of human health playing a role in prevention of many diseases. Plant products provide the organism with crucial nutrients, e.g. vitamins, carbohydrates, protein, bre, and bioactive compounds. The most important groups of phytochemicals are phenolics, alkaloids, organosulphur compounds, phytosterols, and carotenoids (1). Although they are regarded as non-nutritive, these substances serve an important special function. Their impact on the human body consists in inhibition of in ammatory processes, stimulation of the enzymatic and cardiovascular systems, and antimicrobial activity (2,3). Products of plant origin are also a valuable source of micro-and macroelements, in particular potassium, phosphorus, calcium, magnesium, iron, zinc, copper, manganese, and selenium. An insu cient supply of these compounds may be the main cause of periodontal diseases, which affect up to 90% of the world's population (4). Tea, raisins, and cranberries are regarded as functional foods improving oral health (5). As reported by Sierpińska et al. (6), magnesium phosphate and hydroxyapatite are necessary for bone structure, while zinc and copper ensure exibility and integrity of tissues. An adequate supply of zinc in the organism can reduce enamel demineralisation, and the optimal level of copper limits enamel erosion in an acidic environment. A diet rich in vegetables, not only yellow and green ones, and consumption of high-bre foods reduce the risk of early tooth loss (7). Taking into account the number of diet-related diseases, the Food and Nutrition Institute published a new Food Pyramid in 2016 with vegetables and fruit at its base and recommendations that the former should be consumed in larger quantities (8). As reported by Murawska (9), fruit should be eaten 2-3 times a day and vegetables even twice as often. According to WHO, adults should consume 400 g of these products daily (10); however, the consumption of fresh fruit and vegetables (excluding potatoes and juices) in Poland does not exceed 250 g (11).
With its content of minerals, especially calcium and phosphorus, plant food appears to have an important bene cial effect on oral health. However, a diet rich in vegetables and fruit, which contain acids, may contribute to dental erosion, as con rmed in the case of subjects following a vegetarian diet (12). Athletes are especially exposed to enamel erosion since they consume increased amounts of fruit (especially apples) and vegetables and drink beverages with high erosive potential (juices, sparkling vitamin preparations) (13). As shown by Zimmer et al. (14), apple and orange juices have ve-fold higher erosive potential than Coca Cola Light.
The aim of the study was to assess the potential impact of macro-and micronutrients contained in vegetables and fruit on the status of mineralised dental tissues in relation to the hygiene and nutritional habits in 15-year-old adolescents living in randomly selected localities in Lublin Province and Lviv Oblast.

Analysis of plant material
The analyses of the plant material were carried out in Chervonograd and Kraśnik, which were randomly divided into four areas. In each area, four farms were selected to provide vegetables for the analysis, i.e. Daucus carota L. and Solanum tuberosum L., and teenagers from these areas were chosen for the examinations. The plant material was dried and ground. The dry samples were burnt at a temperature of 450 °C. After cooling, the ash was treated with diluted hydrochloric acid in a ratio of 1:2. The content of P, K, Ca, Mg, Mn, Zn, Fe, and Cu was determined in the extract. The content of K, Ca, Mg, and trace elements was determined with the ASA atomic absorption spectrophotometry method (Analyst 300 Perkin Elmer). Phosphorus was determined colorimetrically using ammonium vanadomolybdate. The results of the plant material analyses were subjected to the statistically analysis of variance. The least signi cant difference (LSD) was determined based on Tukey's test at the signi cance level α = 0.05.

Clinical examination
The clinical examination involved teenagers aged 15 (index age group adopted by WHO) attending schools in Chervonograd (Lviv Oblast, Ukraine) and in Kraśnik (Lublin Province, Poland). The investigated group of 110 subjects comprised 60 males and 50 females. Three subjects did not fully meet the conditions of the sociomedical examination.
The clinical examination was conducted in standardised conditions with the use of disposable dental kits in compliance with all principles of sterility and non-invasiveness. The examinations were performed in doctor and nurse o ces.
The examinations were conducted with the use of a dental lamp, a mirror, and a periodontal probe and the data were recorded on anonymous examination sheets/cards labelled with code numbers. The clinical assessment of the oral health in the subjects was carried out in accordance with the WHO recommendations and criteria proposed by this organisation (15). The examiners underwent training combined with the calibration process and determination of the magnitude of error. Cohen's kappa coe cient of agreement between the results of the clinical examination was 0.97. The credibility of the assessments was veri ed by re-examination of every tenth teenager. The status of mineralised dental tissues was assessed based on caries severity expressed by the mean D3MFT number and the SIC index value.

Socio-medical survey
Another part of the study was a socio-medical survey focused on assessment of patients' eating habits. The questions, adjusted to the age of the respondents, were part of questionnaires labelled with the same code numbers as those on the clinical examination cards. The respondents answered questions about the frequency of consumption of fruit and vegetables and fruit juices.
The results were analysed statistically. The database was constructed and statistical analysis was carried out with the use of Statistica 9.1 computer software (StatSoft, Poland).

Plant material
The samples of vegetables collected for the analysis contained varied contents of macronutrients (Table 1). Their concentration depended on the study area and the species. The phosphorus content in dry matter was at the level of 5.00 g·kg − 1 d.w. in the carrot roots but was two-fold lower in the potato tubers. It was also found that the content of this element in the vegetables from Chervonograd was lower, in the case of potatoes by as much as 39%, than in the plants cultivated in Kraśnik. There were signi cant differences in the potassium content between the plants grown in Poland and Ukraine. The vegetables from Kraśnik were characterised by a higher concentration of this element. Regardless of the study area, the potatoes had higher content of this component. Both the study area and the species had an impact on the concentration of calcium and magnesium in the plants. Higher levels of calcium were recorded in the potato tubers (4.30 g·kg − 1 d.w.) than in the carrot roots. An inverse correlation was noted for the content of magnesium. The concentration of both these nutrients was lower in the plants cultivated in Chervonograd. The content of microelements presented in Table 2 varied depending on the species and the cultivation area. Plants grown in Ukraine exhibited a lower concentration of manganese, zinc, iron, and copper. The comparison of both species showed higher levels of these elements in the dry matter of the carrot roots, especially in the case of iron.

Clinical examinations
In total, 110 inhabitants of Kraśnik (n-47) and Chervonograd (n-60) aged 15 were quali ed for the analysis of the study results (three questionnaires were incomplete and the clinical examination was not taken into account in the statistical analysis of the results). The secondary school students from Chervonograd were represented by 45% of girls (n − 27) and 55% of boys (n − 33). The group from Kraśnik comprised 24 boys (48%) and 23 girls (46%). The data are presented in Table 3. The frequency of dental caries was 75% in the subjects from Chervonograd and 88% in those from Kraśnik. This difference was statistically insigni cant (p = 0.138). There were also no statistically signi cant differences in the frequency of caries between the sexes. Its prevalence was 78.79% in the 15-year-old boys from Chervonograd and 95.83% of those living in Kraśnik (p = 0.149). These values in the group of girls were 70.37% and 86.96%, respectively (p = 0.285). The value of the caries frequency index is presented in Table 4. The mean values of the D3MFT number in the group of the 15-year-olds and its components D3T, MT, FT are presented in Table 5.     The value of the SIC index was 8.24 in the students from Chervonograd (n − 21) and 7.33 in the group from Kraśnik (n − 18). This difference was not statistically signi cant (p = 0.287). The data are presented in Table 8. The intensity of caries measured by the mean D3MFT value in the 15-year-old teenagers from Chervonograd who declared everyday consumption of fresh vegetables and fruit was 3.77 (Table 9). In turn, the caries intensity in the group of respondents who ate these products less frequently (every 2-3 days or once a week) was 4.65. This difference was not statistically signi cant (p = 0.470). No statistically signi cant differences were found between the mean values of D3T (p = 0.628), MT (p = 0.940), and FT (p = 0.839).  The analysis of the mean D3MFT number (Speaman's rank correlation) showed lower values of this parameter and its components in respondents who declared less frequent consumption of fruit juices. However, these differences were not statistically signi cant, as shown in Table 11. To make the results as reliable as possible, the survey respondents were asked to indicate the frequency of brushing teeth, the use of uoride toothpaste, and the use of additional oral hygiene products, such as dental oss.
The obtained data are presented in Table 12. Brushing teeth 2-3 times a day was declared by 76% of the respondents from Lviv Oblast and 74% of the teenagers from Lublin Province. This difference was not statistically signi cant (p = 0.746). A vast majority of the respondents brushed their teeth with a brush and toothpaste (98.33% of the teenagers from Chervonograd and 98% from Kraśnik). Additional oral hygiene products were used by 89.13% of the students from Kraśnik and 63.33% from Chervonograd. The differences were statistically signi cant (p = 0.003). Toothpaste with uoride was used by 85.71% of the 15-year-olds from Kraśnik (n-42) and 46.55% of those living in Chervonograd (n-27). The difference was statistically signi cant (p < 0.001).

Discussion
Minerals are essential for the function of every living organism, and their de ciency and excess lead to development of diet-related diseases. As evidenced in the latest research and available literature, human health depends on the consumption of foods of both animal and plant origin. The uptake and absorption of macro-and microelements by humans is in uenced by interactions between these elements and between all compounds contained in food. For example, ascorbic acid has a positive effect on absorption of iron, which is especially important in a plant-based diet (16). In turn, calcium and phosphorus reduce the absorption of magnesium (17).

Chemical composition of vegetables
The presents study showed that the nutrient content varied depending on the cultivation site. Phosphorus is an important macronutrient in the human diet, as it is involved in mineralisation of bones and teeth and contributes to the maintenance of the acid-base balance in the organism. The intake of increased amounts of basic substances, such as phosphorus or calcium, reduces demineralisation and enhances mineralisation of enamel (18). The was higher than the content of 1.29 g·kg − 1 reported by Barczak and Nowak (26).
The present study results indicate large variations in the micronutrient content in the dry matter of potato and carrot tubers. As reported by Zarzecka (27)

Conclusion
Consumption of fruit and vegetables provides the organism with macro-and microelements that exert an effect on oral health. The present results show that carrots are a good source of microelements for humans, whereas potatoes provide potassium and calcium. However, the present study has shown that, despite their unquestionable health value, the content of acids in vegetables should be considered as a factor promoting enamel demineralisation.
Taking into account the effect of macro-and microelements supplied with food on oral health, the frequency of consumption of fruit and vegetables on the D3MFT index was analysed. The comparison of the survey data with the medical examinations of the population of Chervonograd and Kraśnik demonstrated that respondents that consumed vegetables and fruit every day had a higher value of the index, but only in the group from Kraśnik. These differences in the D3T values were con rmed statistically.