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. 2020 Apr 24;2020:6825074. doi: 10.1155/2020/6825074

Nutrition in Herbal Plants Used in Saudi Arabia

Hanan Almahasheer 1,
PMCID: PMC7204254  PMID: 32399314

Abstract

Herbs are used for centuries by many people worldwide. This study derives insights into the use and content of herbs that are consumed among Saudi citizens. An online questionnaire was distributed to understand the basic information about Saudi citizens' preference and daily patterns of herbal plants that are usually used as drinks. Moreover, concentrations of fourteen elements in twenty-one herbal plants that were indicated in the previous questionnaire were collected from the local market and then analyzed using an Inductively Coupled Plasma Emission Spectrometry (ICP). Mint leaves were significantly higher in most of the nutrients analyzed, and mint was the most popular drink among participants, followed by green tea and anise. Most of the citizens preferred to drink one cup only at home and believed that herbs are good for their health and potentially could help them to sleep better. The outcomes derived from this research could help future assessments of diet patterns among Saudi citizens.

1. Introduction

Herbal plants, hereafter, herbs, are one of the most important sources of many elements that are vital for humans and animals' diet and are used to prevent or treat diseases. These elements are necessary nutrients to their lives and are, therefore, needed in food as the body cannot synthesize them [1]. Herbs play an important role in politics, romance, religion, and health [2], and they are still used by millions of people globally, in particular as medicine as there are more than 50 elements considered as a major component of enzymes and proteins [3]. And optimal uptakes of nutrients may reduce health risk [4]; therefore, their use is increasing globally due to their low side effects when used moderately [5]. Hence, knowing the exact elemental composition of food and other products is important to understand the nutritive value [6], while the use of low nutritive refined food products may affect health [7]. Moreover, some of these are essential nutrients to a certain limit, e.g., iron and copper, whereas others, e.g., lead and cadmium, are poisonous [5].

Most of the herbs are naturally grown in many regions around the planet and used from ancient times [8]. They are also used for culinary [9] cosmetics [1012], and up to 80% of the world's population depend on plant-derived drugs for medical purposes [13]. Also, green tea is a good example of the use of herbs that started for centuries in China and Japan [6] and is still used nowadays. However, for safety reasons, it is advisable to assess different pollutants before delivering those herbs to the end user (consumer) [14].

Numerous attempts have been made to determine the element's content in plants around the world, e.g., Nigeria [15] and Malaysia [16]. However, a quick search in Scopus with the keywords “herbal plant” and “nutrient” revealed that most of the published papers are from Asia, i.e., India, China, Iran, and Malaysia. Saudi Arabia's market is rich with various herbal plants that citizens are using as “traditional medicine,” many of those are coming from Asia and Africa, while the rest are harvested locally. Studies concerning elemental content of these herbs that are acquired from the Saudi market are rare, whereas herbal preference among citizens and their knowledge base have not hitherto been performed. As a result, the outcomes of this research would serve as a base for further assessments related to herbal plants in Saudi Arabia and describe patterns of practices among Saudi citizens.

2. Materials and Methods

2.1. Questionnaire

To assess the public preference regarding herbal plants that are usually used on a daily basis by people in Saudi Arabia, a survey was carried out online in 2018. The participants were asked before starting the survey if they do drink herbal tea; if no, the survey was terminated. The panel respondents who were above 18 years old were invited to participate via Google survey online (https://gsuite.google.com/products/forms/). However, only 44 participants were under 18 which corresponds to 4% only; therefore, their answers were not excluded from the results. Demographic characteristics (i.e., questions about sex, age, and educational stage were asked to identify the range of participants) are shown in Supplementary Table S1. The questionnaire was designed to include the following: From where do you get your herbs, why do you drink herbal tea, does it help you sleep, where do you drink it, how many cups per day, how many scoops of the herb do you use per cup, and which herbs do you drink, along with options to choose from which are in Supplementary Table S2. The questionnaire was in the Arabic language; then, the results were translated to English.

2.2. Collection of the Samples

Twenty-one herbal plants that were indicated in the previous questionnaire (Table 1 and Figure 1) were collected from a local market in Dammam, Saudi Arabia, in 2018. The material was already dried; therefore, three replicated samples (n = 3) from each herb were directly ground in an agate mortar. The scientific name and family of each herb were further investigated using Encyclopedia Britannica (http://www.britannica.com) and Herbal Encyclopedia (https://www.cloverleaffarmherbs.com).

Table 1.

Herbal plants used in this study.

Number Name Family Part assayed
Common Scientific
1 Lemon balm Melissa officinalis Labiatae Leaves
2 Anise Pimpinella anisum Umbelliferae Seeds
3 Olive leaves Olea europaea Oleaceae Leaves
4 Cinnamomum Cinnamomum verum Lauraceae Tree bark
5 Rose Rosa species Rosaceae Flowers
6 Chamomile Matricaria chamomilla Asteraceae Flowers
7 Roselle Hibiscus sabdariffa Malvaceae Flowers
8 Fennel Foeniculum vulgare Umbelliferae Seeds
9 Marjoram Origanum majorana Labiatae Leaves
10 Ajwain Trachyspermum ammi Apiaceae Seeds
11 Mugworts Artemisia vulgaris Asteraceae Leaves and twigs
12 Sage Salvia officinalis Labiatae Leaves and twigs
13 Laurel leaf Laurus nobilis Lauraceae Leaves
14 Licorice Glycyrrhiza glabra Fabaceae Roots
15 Maidenhair Adiantum Polypodiaceae Leaves and twigs
16 Curcuma Curcuma longa Zingiberaceae Rhizome
17 Star anise Illicium verum Schisandraceae Seeds
18 Thyme Thymus vulgaris Lamiaceae Leaves
19 Green tea Camellia sinensis Theaceae Leaves
20 Mint Mentha Labiatae Leaves
21 Dried black lime Citrus aurantifolia Rutaceae Fruit

Figure 1.

Figure 1

Images of herbal plants acquired and analyzed, which correspond to plants in Table 1.

2.3. Chemical Analysis and Data Quality

Plant samples were already dried, then ground using a granite mortar, and photographed; then, 0.5 grams of the plant sample (i.e., leaves, stem, or seeds) was digested with 5 mL of concentrated HNO3 and 2 mL of H2O2 in polyethylene tubes at digestion systems for 2 hours at 100°C [17]. The digested samples were left to cool, then diluted to 45 mL with Milli-Q water (18.2 Ω/cm), then filtered with a Whatman filter paper of 44-micron size. Concentrations of fourteen elements: calcium (Ca), chromium (Cr), copper (Cu), iron (Fe), iodine (I), potassium (K), magnesium (Mg), manganese (Mn), molybdenum (Mo), sodium (Na), nickel (Ni), phosphorus (P), selenium (Se), and zinc (Zn), were analyzed using Inductively Coupled Plasma Emission Spectrometry (Shimadzu, model 9820). To confirm the quality of the analysis, replicates and PanReac AppliChem multielement standard solution between the 20 samples were used. The analytical recovery of the standards and the duplicated samples is reported in Table 1.

2.4. Statistical Analysis

Descriptive statistics and general linear models were used to test the effects of differences among herbs for every single element as well as Tukey's HSD (honestly significant difference) post hoc test was used to assess pairwise differences. Moreover, assuming that the average consumption of herbs is one spoon equivalent of 0.5 g, the estimated dietary intake (mg day−1) based on 70 kg body weight was calculated by dividing the nutrient concentration (mg kg−1) by 70. All statistics were computed using JMP v12 (Table 2).

Table 2.

Summary of certified standards and the duplicated samples measured, along with the selected wavelength of each element analyzed.

Element Symbol Wavelength % Recovery
Standard Duplicated samples
Calcium Ca 220.86 99 86
Chromium Cr 205.55 100 113
Copper Cu 261.84 98 98
Iron Fe 259.94 101 82
Iodine I 178.28 112 89
Potassium K 766.49 86 93
Magnesium Mg 279.55 98 120
Manganese Mn 260.57 96 88
Molybdenum Mo 202.03 102 100
Sodium Na 589.59 87 94
Nickel Ni 231.60 100 94
Phosphorus P 213.62 96 86
Selenium Se 203.99 95 89
Zinc Zn 213.86 98 95

3. Results

The range of participants who answered the online survey that was distributed through the social media was from 12 to 70 years old, with about 1200 participants in about 10 days (only 44 participants were under 18 years old which corresponds to 4% only; therefore, their answers were not excluded from the results). Female participants were the highest comprising about 77%, while male participants were only 23%. Details of age and sex along with the education level of participants are summarized in Supplementary Table S1.

The majority of participants, i.e., 75% of the participants, have their herbal tea at home, and 22% of the participants drink it anywhere, whereas only 2% and 1% have it at the coffee shop or at work. Moreover, 79% of the participants believe that drinking herbal tea is good for health, while 15% prefer it just for the taste, 2% chose it for the smell, and 4% have other reasons. Interestingly, about 83% answered yes or maybe to the question about if they believe if the herbal tea would help them to sleep, while only 18% answered with no. Additionally, about 58% answered that they get it from their mothers or herb specialists, whereas 43% from the supermarket (Figure 2 and Supplementary Table S2).

Figure 2.

Figure 2

Analyses of survey questions (from where do you get your herbs, why do you drink herbal tea, does it help you sleep, and where do you drink it?).

Furthermore, 71% (i.e., 852 participants) of the 1200 preferred to drink only one cup of herb a day; 60% out of those (852 participants) prepared it with only one spoon, 8% prepared it using two spoons, and only 3% used three spoons. Moreover, 20% (i.e., 240 participants) of 1200 preferred to drink two cups of herb a day; 20% of those (240 participants) prepared it with only one spoon, 5% prepared it using two spoons, and only 2% used three spoons. Finally, only 28 participants preferred three cups a day, and 1%, 0.3%, and 0.8% preferred one, two, and three spoons per cup, respectively (Figure 3 and Supplementary Table S2).

Figure 3.

Figure 3

Analyses of survey questions (how many cups do you consume per day, and how many scoops of herb do you use per cup?).

The majority of the Saudi participants (about 85%) preferred to drink mint, followed by 69% favoring green tea and then 59% with anise. Moreover, Chamomile, Cinnamomum, Sage, Roselle, Thyme, Marjoram, and Fennel were intermediate with 44, 31, 30, 26, 22, 17, and 16% respectively while the rest (i.e., rose, curcuma, mugworts, ajwain, star anise, lemon balm, olive leaves, licorice, laurel leaf, maidenhair, and dried black lime) were ≤10% (Figure 4).

Figure 4.

Figure 4

Analyses of the survey question, (which herbs do you drink?).

Most of the elements analyzed, i.e., Ca, Cu, Fe, Cr, Mn, Ni, and Se, were significantly higher in mint, maidenhair, green tea, dried black lime, and laurel leaf whereas Zn, Na, and Mg were significantly higher in mugworts, and K was significantly higher in both mugworts and curcuma. Moreover, P, Mo, and I were significantly higher in lemon balm, dried black lime, and mint, respectively (Table 3, Tukey's HSD, P < 0.05).

Table 3.

Average ± standard error (SE) of fourteen elemental concentrations (mg kg−1) for twenty-one herbs (n = 3) collected from Saudi Arabia.

Ca Cr Cu Fe I K Mg Mn Mo Na Ni P Se Zn
Sage 429 ± 5de 339 ± 5bc 376 ± 3e 430 ± 4d 1210 ± 17defg 1970 ± 81ef 1467 ± 20cd 107 ± 2c 559 ± 8de 998 ± 80defg 388 ± 5c 1127 ± 23abcde 981 ± 12bcd 247 ± 5bc
Ajwain 345 ± 57de 203 ± 120c 269 ± 125e 159 ± 86d 724 ± 169ghij 1152 ± 179f 556 ± 398de 125 ± 9c 424 ± 62de 333 ± 173fg 233 ± 109c 840 ± 405 def 569 ± 116efgh 185 ± 15 ef
Anise 497 ± 6cde 299 ± 5bc 660 ± 14de 355 ± 5d 1087 ± 17efgh 9147 ± 116b 1503 ± 19cd 156 ± 6c 463 ± 8de 1303 ± 39defg 332 ± 5c 1447 ± 18abc 730 ± 8def 194 ± 3ef
Chamomile 323 ± 3e 274 ± 3c 308 ± 9e 360 ± 10d 1165 ± 49defgh 3855 ± 193de 981 ± 225cde 119 ± 3c 416 ± 1de 746 ± 86efg 309 ± 3c 1067 ± 169bcde 580 ± 18efg 190 ± 10 ef
Cinnamomum 309 ± 27e 156 ± 49c 153 ± 24e 69 ± 24d 608 ± 34ghij 2213 ± 179ef 249 ± 12e 138 ± 16c 302 ± 38e 390 ± 80fg 169 ± 21c 433 ± 34f 417 ± 32fghi 120 ± 7g
Curcuma 280 ± 25e 224 ± 4c 178 ± 41e 235 ± 16d 550 ± 53 hij 12133 ± 120a 907 ± 346de 135 ± 8c 327 ± 8e 342 ± 85fg 227 ± 8c 592 ± 14ef 388 ± 21ghi 121 ± 2g
Dried black lime 2693 ± 97a 1327 ± 48a 2977 ± 80ab 2533 ± 77a 2280 ± 76ab 6737 ± 155bc 1014 ± 36cde 834 ± 30a 1563 ± 304a 7467 ± 149bc 3050 ± 235a 1257 ± 43abcd 1317 ± 38a 251 ± 9abc
Fennel 610 ± 9cde 321 ± 7bc 593 ± 55de 293 ± 11d 1160 ± 20defgh 8750 ± 163b 1980 ± 21bc 177 ± 6c 516 ± 11de 2488 ± 998def 340 ± 8c 1587 ± 28ab 916 ± 23cd 197 ± 4def
Green tea 2623 ± 90ab 1293 ± 43a 3150 ± 121a 2607 ± 98a 2243 ± 97ab 7073 ± 286bc 990 ± 34cde 813 ± 28a 1267 ± 41ab 8433 ± 398bc 2860 ± 115a 1230 ± 55abcd 1297 ± 38ab 248 ± 10bc
Laurel leaf 2697 ± 85a 1327 ± 41a 2853 ± 186ab 2480 ± 121ab 2220 ± 145abc 6193 ± 315cd 1011 ± 31cde 834 ± 26a 1157 ± 66abc 6273 ± 496c 2607 ± 172a 1220 ± 58abcd 1287 ± 35ab 244 ± 9bcd
Lemon balm 453 ± 93cde 429 ± 2bc 388 ± 96e 555 ± 1d 1593 ± 3cde 1227 ± 116f 872 ± 602de 140 ± 1c 726 ± 3 cde 155 ± 62fg 146 ± 93c 1673 ± 13a 1200 ± 6abc 289 ± 3ab
Licorice 1610 ± 538abc 416 ± 16bc 823 ± 44de 573 ± 51d 1027 ± 27efghi 3847 ± 102de 2560 ± 92b 196 ± 4c 608 ± 19de 3067 ± 397de 472 ± 23c 1110 ± 32 abcde 944 ± 27cd 225 ± 9 cde
Maidenhair 2733 ± 67a 1347 ± 33a 3310 ± 80a 2723 ± 67a 2337 ± 85ab 7557 ± 169bc 1030 ± 25cde 845 ± 20a 1317 ± 33ab 9243 ± 167b 3047 ± 69a 1287 ± 30abcd 1340 ± 32a 257 ± 5abc
Marjoram 301 ± 109e 343 ± 27bc 425 ± 43e 451 ± 65d 1192 ± 150defg 2187 ± 175ef 1280 ± 52cde 123 ± 6c 520 ± 46de 858 ± 144efg 386 ± 53c 1130 ± 166abcde 874 ± 93 de 232 ± 9 cde
Mint 2753 ± 37a 1357 ± 19a 3327 ± 34a 2720 ± 25a 2383 ± 46a 7727 ± 91bc 1040 ± 15cde 852 ± 11a 1313 ± 18ab 9560 ± 140a 3087 ± 39a 1297 ± 18abcd 1347 ± 24a 259 ± 3abc
Mugworts 1213 ± 18cde 560 ± 7bc 1560 ± 40cd 779 ± 14cd 1497 ± 19def 12667 ± 133a 6083 ± 87a 335 ± 7bc 899 ± 10bcd 15267 ± 145a 655 ± 8bc 1427 ± 19abcd 1320 ± 15a 300 ± 2a
Olive leaves 568 ± 79cde 225 ± 42c 403 ± 71e 177 ± 33d 883 ± 75fghi 2467 ± 413ef 971 ± 130cde 128 ± 13c 437 ± 38de 407 ± 102fg 378 ± 87c 888 ± 124cdef 824 ± 125de 171 ± 12f
Rose 143 ± 1e 143 ± 1c 41 ± 5e 77 ± 4d 242 ± 22j 587 ± 19f 564 ± 121de 68 ± 2c 367 ± 167e 576 ± 41fg 126 ± 0c 418 ± 9f 167 ± 11i 86 ± 1g
Roselle 285 ± 70e 349 ± 5bc 419 ± 17e 375 ± 34d 1210 ± 15defg 1980 ± 26ef 1490 ± 26cd 243 ± 5c 576 ± 9de 659 ± 71fg 440 ± 17c 1073 ± 12 abcde 977 ± 6 bcd 244 ± 3 bcd
Star anise 204 ± 7e 153 ± 5c 191 ± 17e 139 ± 56d 395 ± 27ij 1122 ± 123f 514 ± 42de 172 ± 3c 352 ± 117e 54 ± 26g 162 ± 5c 427 ± 12f 254 ± 7hi 97 ± 3g
Thyme 150 ± 789bcd 762 ± 378b 1949 ± 876bc 1587 ± 735bc 1745 ± 427bcd 4185 ± 1891de 871 ± 184de 604 ± 243ab 902 ± 190bcd 3298 ± 1523d 1600 ± 761b 1055 ± 123bcde 1045 ± 171abcd 215 ± 26cdef
F ratio
P value
22∗∗ 26∗∗ 35∗∗ 36∗∗ 31∗∗ 67∗∗ 38∗∗ 31∗∗ 17∗∗ 93∗∗ 38∗∗ 10∗∗ 39∗∗ 43∗∗

The results (F ratio and Pvalue: =0.05 > P > 0.01; ∗∗=P < 0.01) from ANOVA. Different letters a, b, c, and d indicate significant differences among different herbs for every single element (Tukey's HSD multiple comparison post hoc test, P < 0.05).

4. Discussion

The Recommended Dietary Allowance (RDA) is the sufficient amount of required nutrients that are needed for healthy individuals, which are established by the Food and Nutrition Board [18]. Herbal plants are one of the major resources of these nutrients and, therefore, the amount of nutrients in plants is one of the criteria that makes it favorable to use [6], although the paucity of these nutrients can lead to disease [1]. Many of them are essential nutrients for humans; e.g., iron is basic to hemoglobin and many enzymes, while calcium and phosphorous are essential components to bones, magnesium is important to all biosynthetic processes, and zinc is basic to many enzymes that are involved in metabolic pathways [19].

The estimated dietary intake (mg day−1) in this study compared to the RDA varied among different elements. That is, Ca, K, Mg, Na, P, and Zn were within the recommended range of intake for males and females (Table 4) while Cr, Cu, I, Mo, and Se were higher than the range of the reported values and finally Fe and Mn were intermediate with seven herbs (i.e., black lime, green tea, laurel leaf, maidenhair, mint, mugworts, and thyme; Table 4) out of twenty-one being higher than the RDA values reported by Dell Valle et al. [20].

Table 4.

Median nutrient intake values by herbs based on 70 kg body weight (mg day−1).

Ca Cr Cu Fe I K Mg Mn Mo Na Ni P Se Zn
Sage 6 5 5 6 17 27 21 2 8 14 6 16 14 4
Ajwain 4 2 5 2 8 15 3 2 5 5 4 6 7 3
Anise 7 4 10 5 15 132 21 2 7 18 5 21 10 3
Chamomile 5 4 4 5 17 55 14 2 6 11 4 15 8 3
Cinnamomum 5 2 2 1 9 32 4 2 5 6 2 7 6 2
Curcuma 4 3 2 4 8 174 10 2 5 5 3 9 5 2
Dried Black lime 40 20 43 37 33 97 15 12 18 105 40 19 19 4
Fennel 9 5 9 4 17 124 28 3 8 49 5 23 13 3
Green tea 37 18 45 37 33 101 14 12 18 120 41 17 19 4
Laurel leaf 39 19 42 35 31 91 15 12 17 91 38 17 18 4
Lemon Balm 8 6 5 8 23 17 5 2 10 2 1 24 17 4
Licorice 22 6 12 9 14 54 37 3 9 39 7 16 13 3
Maidenhair 40 20 48 40 34 110 15 12 19 133 44 19 19 4
Marjoram 4 5 6 6 16 30 18 2 7 11 5 17 12 3
Mint 40 20 48 39 34 111 15 12 19 137 44 18 19 4
Mugworts 17 8 23 11 22 183 88 5 13 219 9 21 19 4
Olive leaves 8 3 7 3 13 41 14 2 6 5 5 13 13 3
Rose 2 2 1 1 3 8 9 1 3 8 2 6 2 1
Roselle 5 5 6 6 17 28 21 3 8 9 6 15 14 4
Star anise 3 2 3 3 5 18 7 2 3 1 2 6 4 1
Thyme 22 12 40 30 30 85 15 12 15 63 30 16 16 3
Males (9 to >70 y) 1000–1300 0.03–0.04 0.07–0.09 8–11 0.1–0.2 4500–4700 240–420 1.9–2.3 0.03–0.05 1200–1500 700–1250 0.1 8–11
Females (9 to >70 y) 1000–1300 0.02–0.03 0.07–0.09 8–18 0.1–0.2 4500–4700 240–320 1.6–1.8 0.03–0.05 1200–1500 700–1250 0.1 8–9

RDA values from [20]

Moreover, in this study, two-thirds of the participants were females, indicating a higher rate of use among females; this rate of female users was observed by the findings of Alghamdi et al. [21]. The growing interest of females to herbal drinks, e.g., tea, might be due to the daily news of their benefits that ranged from the protection of hip structure in elderly women [22] to cancer potential treatments and risks caused by diabetes [23].

While there is no explanation why the majority drink only one cup of herbal tea preferring it at home compared to the work place, and around half of the participants acquire it from their moms or specialists, yet, in general, about 79% of the participants believed that herbal tea is good for their health compared to smell and taste, and 83% believed that it may help them sleep. Similarly, a recent study on two hundred patients in Saudi Arabia found that 76% of the patients with chronic illness had used herbal medicine [21], compared to a lower range of 10 to 52% in western countries [24]. And a higher range of migrants of about 75% uses herbal medicine in the west [25].

Mint was the most popular herb among Saudi citizens, followed by green tea and anise. In Australia, mint comes as number seven of most sold herbs and spices in the supermarket for 2013 with about $2151500 of sales value [26]. However, many studies documented the effect of green tea as a potential treatment preventing cancer [27, 28]. Furthermore, most of the nutrients, i.e., Ca, Cu, Fe, Cr, Mn, Ni, and Se, were significantly higher in mint, maidenhair, green tea, dried black lime, and laurel leaf, whereas nutrients' concentrations in this study, particularly, Zn, Na, K, and Mg, were significantly higher in mugworts compared to other herbs, which is coherent with early Chinese beliefs of the medical benefits of mugworts, as well as France in the middle ages, where they used it to protect babies from cold [2].

Nevertheless, these herbs must be used with care, as many reports have documented the presence of toxic heavy metals and undeclared pollutants, e.g., in Asia [2931] and Africa [32, 33].

5. Conclusion

The concentration of nutrients carried out was depending on the plant species analyzed; most of the herbs analyzed were within the RDA limits. However, participants who selected many cups per day or many spoons per cup could be at risk of bioaccumulation. In this study, mint leaves were significantly higher in most of the nutrients analyzed, and mint was the most popular drink among Saudi citizens, followed by green tea and anise.

Acknowledgments

The author is thankful to Science College Research Units at Imam Abdulrahman Bin Faisal University (IAU), for providing chemicals and analyzing samples in the ICP unit, in particular, Amnah Alharbi and Rasha Almalih. The author is also thankful to Sarah Alhajri for purchasing the used herbs from the local market.

Data Availability

The data used to support the findings of this study are included within the supplementary information files.

Conflicts of Interest

The author declares that there are no conflicts of interest.

Supplementary Materials

Supplementary Materials

Supplementary Tables S1 and S2: questions about sex, age, and educational stage were asked to identify the range of participants.

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Supplementary Materials

Supplementary Tables S1 and S2: questions about sex, age, and educational stage were asked to identify the range of participants.

Data Availability Statement

The data used to support the findings of this study are included within the supplementary information files.


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