Investigating the Effect of an Educational Intervention on Fruit and Vegetable Consumption and its Effect on Blood Lipid Levels in Government Employees: A Clustered Randomized Trial

Document Type : Original Research

Authors
F. Khatty Dizabadi 1
Z. Makvandi 2
J. Yazdani Cherati 3
F. Mostafavi 4
1 Department of Public Health, School of Health, Mazandaran University of Medical Sciences, Sari, Iran
2 Department of Public Health, Asadabad School of Medical Sciences, Asadabad, Iran
3 “Department of Biostatistics, Faculty of Health” and “Centre Addiction Research Institutes”, Mazandaran University of Medical Sciences, Sari, Iran
4 Department of Health Education and Promotion, School of Health Isfahan University of Medical Sciences, Isfahan, Iran
10.58209/hehp.11.3.365
Abstract
Aims: The consumption of fruits and vegetables has a protective effect on cardiovascular disease and its associated risk factors. The present study aimed to assess the effect of educational intervention on fruit and vegetable consumption, as well as its effect on blood lipid parameters, in government employees.

Materials & Methods: This quasi-experimental cluster-randomized controlled trial was conducted in two offices in Qaem Shahr. The data collection tool included a 31-item questionnaire on the frequency of fruit and vegetable consumption and a laboratory test to measure blood lipid parameters. The Chi-square test, t-test, paired sample t-test, and ANCOVA were used for data analysis.

Findings: The study groups significantly differed in mean fruit and vegetable consumption after the six-month intervention (p<0.001). The mean total cholesterol (p<0.001) and low-density lipoprotein-cholesterol (LDL-C; p=0.005) levels were significantly different between the groups after the intervention. The mean difference of high-density lipoprotein (HDL)-cholesterol levels showed a significant relationship with the study groups and the interaction of gender and group (p<0.001). The mean difference of total cholesterol (p=0.008) and LDL-C had a significant relationship with the study groups (p=0.03).

Conclusion: Increased consumption of fruits and vegetables is only effective in improving the levels of total cholesterol and LDL-C, but not in lowering triglyceride and HDL-C levels. Therefore, influencing factors, such as the duration of fruit and vegetable consumption, as well as the time required to monitor their effect on these parameters, should be more closely examined.

Keywords

Subjects

Introduction
According to the report of the World Health Organization, 17.9 million people died in 2019 due to cardiovascular diseases [1]. Dyslipidemia is an important risk factor for cardiovascular diseases in more than 50% of adults [2, 3]. Blood lipid disorder is one of the major and modifiable risk factors for cardiovascular diseases [4]. Therefore, lipid disorders have predicted the incidence of cardiovascular disease among Iranians over 50 years old in recent years [5]. In the studies conducted in Iran, 80.5% of the urban population aged 15-64 years in West Azarbaijan province and 85.6% of the population aged 20-65 years in Khuzestan province had dyslipidemia [6, 7]. The results of multiple studies, including systematic reviews and meta-analyses, confirmed the relationship between fruit and vegetable consumption and reduced risk of cardiovascular disease, but some other studies found only fruit intake to be effective in reducing the risk of metabolic syndrome [8-13]. About 1% of Disability Adjusted Life Years (DALYS) and 2.8% of deaths worldwide are caused by insufficient consumption of fruits and vegetables [14]. A minimum daily intake of fruits and vegetables has been recommended for the prevention of chronic diseases. For instance, the intake of a minimum of 800 g of fruits and vegetables per day has been suggested for the prevention of coronary heart disease, stroke, and cardiovascular disease [9]. Since fruits and vegetables are a rich source of vitamins, minerals, fiber, and antioxidants, they have a protective effect on cardiovascular disease and its associated risk factors [15]. Fruits and vegetables due to their high antioxidant activity, can exert a preventive effect on some chronic diseases, including cardiovascular diseases [16-20]. Numerous studies have pointed to the inverse relationship between fruit and vegetable consumption and a decrease in low-density lipoprotein-cholesterol (LDL-C) concentration [21-23]. The intake of fruits and vegetables rich in flavonoids, which are powerful antioxidant agents, can be independently associated with a decreased level of LDL-C [24]. The results of a systematic review indicated that vitamin C, which is another type of antioxidant [25], can affect lipid profiles in some groups, especially those with low levels of plasma vitamin C [26]. Fruits and vegetables contain fiber in two forms, soluble and insoluble, and while the insoluble fiber causes people to feel full, it causes a decrease in food intake and weight loss, and finally it is excreted from the body, but its soluble type is useful in reducing blood fats, while only less than 5% of people receive the recommended amount of this type of fiber daily [27]. Therefore, these results can provide considerable support for public health recommendations and interventions to increase the consumption of fruits and vegetables to prevent cardiovascular disease, cancer, and premature deaths [9]. Increased consumption of fruits and vegetables is vital not only to maintain life but also to improve the welfare of society [28]. Considering the importance of preventive interventions and their lower cost compared to treatment, it is necessary to carry out primary prevention programs at the community level by targeting cardiovascular disease risk factors to reduce deaths caused by this disease through environmental modification and lifestyle changes [29]. The workplace is one of the suitable places, in which we can implement nutritional interventions. The workplace provides an opportunity to have access to large numbers of people who would otherwise be less likely to engage in preventive health behaviors [30-33]. In addition, these workplace interventions can successfully improve the health of different socio-economic and cultural sectors by targeting people who work at different levels of the same environment [34]. In light of the aforementioned issues, the present study aimed to assess the effect of educational intervention on fruit and vegetable consumption, as well as its effect on blood lipid parameters, in government employees working in Qaem Shahr City.

Materials and Methods
This study was registered at the Iranian Registry of Clinical Trials (IRCT20191127045527N1).
Study design
This quasi-experimental cluster-randomized controlled trial (CRCT) was conducted in two offices in Qaem Shahr (with at least 70 employees in the office) in 2021. Therefore, firstly, two offices were randomly selected as clusters for the intervention and control groups. Thereafter, participants were selected via the available sampling method from each selected department. The inclusion criteria were as follows: Being employed in the selected offices, completing the consent form to participate in all stages, not taking antioxidant tablets, such as vitamin C, E, and beta-carotene, as well as other supplements, for three months before the study, not being on a vegetarian diet, the absence of diseases, such as cancer and cardiovascular disease, kidney disease, liver disease, diabetes, infectious and metabolic diseases, and digestive diseases (based on medical documents). On the other hand, the exclusion criteria entailed unwillingness to continue participating in the study, being absent during the implementation of the intervention (for subjects in the intervention group), being absent for blood sampling, any medical requirement to use supplements or other antioxidant compounds during the interventions or suffering from diseases, such as cardiovascular, digestive, diabetes, liver, kidney, infectious, and metabolic diseases, and cancer. Employees from each office were registered in the study through notification using administrative automation. After being informed of the study objectives and assessing the inclusion criteria, 70 subjects were entered into the study by simple random. The data collection tools included a 31-item questionnaire on the frequency of fruit and vegetable consumption that was developed based on available fruits and vegetables in the region with the help of nutrition experts. Data regarding the mean consumption of fruits and vegetables per day, week, month, six months, or non-consumption were collected using this tool according to the recommended amount of each unit stated in the questionnaire. Moreover, considering the seasonal changes in the availability of fruits and vegetables, the average unit consumption of fruits and vegetables for six months before and after the intervention was extracted. The validity of this questionnaire was checked by experts from the nutrition department, and the reliability of the questionnaire was obtained at 0.71 using a test-retest method. A laboratory test was used to measure the blood lipid parameters of the subjects. In order to measure the amount of serum lipid parameters, the target groups were referred to the medical diagnostic laboratory in the first stage, before the intervention (baseline), and in the second stage (four months after the end of the intervention), observing at least 10-12 hours of fasting. In order to measure the investigated factors, 2 ml of fasting blood was taken from the target groups (intervention and control groups) using a syringe (2.5cc). Blood samples were placed in a centrifuge for 0.5-1 hour to separate at least 0.5-1ml of serum at 2800rpm. Serum-separating tubes were from the activator type (tube clot activator red), which are used as clot activator tubes as one of the advantages of the work. Thereafter, the isolated sera were kept at -20°C until the test. The measurement of HDL-cholesterol and LDL-C was performed using a kit provided by Pishtaz Teb Company. This kit can measure HDL-cholesterol in the range of 2-150mg/dl and LDL-C in the range of 1-450mg/dl. Cholesterol and triglyceride were measured in the range of 5-500 and 5-700mg/dl by the photochromic method using the cholesterol (CHOD) and triglycerides (GPO-PAP) kit provided by Pars Azmoon Company. The intervention group was administered an eight-week face-to-face educational intervention and six online sessions (via WhatsApp and Telegram for one month) using educational materials, such as posters and pamphlets, on the importance of fruit and vegetable consumption and ways to overcome major obstacles in this regard. No educational and environmental intervention was performed in the control group.
Data analysis
The collected data were analyzed by SPSS 22. The Chi-square and t-test were used to investigate the relationship between the underlying variables of two intervention and control groups; a t-test was employed to compare the mean blood serum lipid parameters and the mean six-month consumption of fruits and vegetables between the two interventions and control groups before and after the intervention. A sample t-test was used to compare the mean score of blood serum lipid parameters and the mean six-month consumption of fruits and vegetables in the intervention and control groups separately before and after the intervention. Also, the analysis of covariance (ANCOVA) was employed to compare the mean levels of blood lipids in the study groups, gender, and the interaction effect of the group and gender by controlling the impact of age as a confounding variable.

Findings
The mean age of participants in the intervention and control groups was 42.11±6.82 and 38.41±5.29, respectively. Other demographic characteristics are presented in Table 1. There was a significant difference between the intervention and control groups in terms of age (p=0.01; Table 1). Before the intervention, the mean six-month scores of consumption of fruits and vegetables in the intervention group and in the control group were not significant (p>0.05), Nonetheless, after the intervention, these mean values were significantly different (p<0.001; Table 2).

Table 1) Baseline characteristics of participants in the intervention and control groups


Table 2) Comparison of the mean levels of blood lipid parameters and fruit and vegetable consumption before and after intervention in two groups


The difference in the mean serum levels of triglyceride, total cholesterol, HDL-C, and LDL-C between the intervention and control groups was not significant before the intervention (p=0.06, p=0.23, p=0.80, and p=0.80, respectively). Nevertheless, after the intervention, these mean values were significant regarding total cholesterol (p<0.001), HDL-C (p= 0.001), and LDL-C (p=0.005).
The mean total cholesterol (p=0.002) and HDL-C (p<0.001) levels in the intervention group before and after the intervention, as well as HDL (p<0.001) and LDL-C (p=0.005) levels in the control group before and after the intervention were significantly different (Table 2). The intervention and control groups did not differ significantly in the mean score of six-month consumption of fruits and vegetables before the intervention (p>0.05). Nonetheless, after the intervention, the intervention and control groups were significantly different in this regard (p<0.001). The mean score of six-month consumption of fruits and vegetables before and after the intervention in the intervention group was significantly different (p>0.05).
The mean score of consumption of fruit before and after the intervention in the control group showed a statistically significant difference and decreased compared to before the intervention (p=0.003). However, the mean score of consumption of vegetables before and after the intervention in the control group was not significantly different (p=0.11; Table 2). The covariance results showed that the mean difference in triglyceride levels considering the group, gender, and the interaction effect of group and gender was not significant (p>0.05). The mean difference in total cholesterol levels had a significant relationship with the intervention group (p=0.008).
The mean difference in HDL-C levels had a significant relationship with the study groups and the interaction effect of gender and the group (p<0.001). The mean difference in total cholesterol (p=0.008) and LDL-C levels had a significant relationship with the study groups (p=0.03; Table 3).

Table 3) Relationship between the mean blood lipid levels according to group and gender by controlling the confounding effect of age using analysis of covariance


Discussion
According to the results of a review study by Karkhah et al., fiber and various vitamins, which are known as antioxidants and found in fruits and vegetables, can effectively lower the level of blood lipids and subsequently prevent cardiovascular disease [35]. This study attempted to investigate the effect of educational interventions on increasing the consumption of fruits and vegetables and, in turn, lowering the level of blood lipid parameters. The results of the present study pointed out that the educational interventions were effective in increasing the consumption of fruits and vegetables in the intervention group after the intervention and also compared to the control group. The present study proposed the hypothesis that an increase in fruit and vegetable consumption can effectively reduce blood lipid parameters. Nonetheless, a significant decrease was observed only in cholesterol and LDL-C levels in the intervention group compared to the control group after the intervention. This level of reduction in the intervention group was not significant before and after the intervention; however, in the control group, the level of the mentioned parameter showed a significant increase compared to before.
There was no significant change in triglyceride levels; nonetheless, there was a significant decrease in HDL-C levels between the two groups, as well as before and after the intervention in the same group. However, the study by Hosseinpour Niazi et al. on adults for 8-9 years demonstrated that fruit and vegetable intake had an inverse relationship with the risk of metabolic syndrome, which consists of elevated blood pressure, blood sugar, and triglyceride levels, as well as decreased HDL-C levels. In other words, apart from improving other metabolic factors, fruit consumption was effective in reducing triglyceride and increasing HDL levels [36]. These findings are not in line with those obtained in the present study. This discrepancy can be ascribed to differences in follow-up time to measure changes in lipid parameters; a longer period of time is probably needed to reduce the levels of triglyceride and elevate the HDL-C levels.
Nevertheless, studies on the effect of vitamin C and E supplements have reported contradictory results. For example, Bobeuf et al. (2011) in Canada showed a significant effect of vitamin C and E supplementation on the reduction of lipid levels in the blood after six months [37]. Malekahmadi et al. assessed the effect of vitamin C and E supplementation on blood parameters in the elderly, and 6 and 12 months after the intervention, no significant effect was observed between the two groups of control and intervention, as well as before and after the intervention in the same group [38].
In the study by Montazerifar et al., an administration of vitamins C and E for two months in dialysis patients was effective and significant only in improving HDL-C levels [39]. Therefore, considering the different results obtained in various studies, it is seemingly better to include homogeneous participants in the study. For example, subjects should be matched in terms of age groups, presence or absence of certain underlying or chronic diseases, presence or absence of disorders in blood lipid parameters, as well as other issues that can have an impact on obtaining different results. For example, Khatti-Dizabadi et al. showed that gender was an effective factor in fruit and vegetable consumption in their study groups; the consumption of fruits and vegetables was higher in women than in men [40].
In this study, the mean age of the participants in the two groups was not the same; therefore, age was included as a confounding factor, and based on the results, it was revealed that the difference in the mean total cholesterol was not associated with age and gender. However, it was correlated with the participating groups. The mean difference in HDL cholesterol was not related to the age and gender of the participants in the study; nonetheless, it was associated with the study groups and the interaction effect of gender with the group. In other words, the mean level of HDL was lower in the intervention group and higher in males. In other words, in the intervention group, it was 10.59 units less than in the control group. The correlation coefficient in this model was 0.09. In other words, it explained 0.09 of the variance of the model with a test power of 0.95. Moreover, the mean difference in HDL-C levels in male participants in the intervention group was 8.76 units higher than that of females in the intervention group, as well as females and males in the control group. The correlation coefficient in this model was also 0.05; it explained 0.05 of the variance of the model with the test power of 0.73. On the other hand, the mean difference in LDL-C levels was not related to age, gender, and the interaction effect of gender and group; nonetheless, it was related to study groups. In other words, the mean difference in the intervention group was 16.93 units less than that in the control group. The correlation coefficient in this model was 0.03; it explained 0.03 of the variance of the model with the test power of 0.57. It is suggested to investigate some other factors, such as the duration of fruit and vegetable consumption, as well as the time required to monitor their effect to uncover the reasons behind its ineffectiveness in improving the level of triglyceride and HDL-C.
Strengths and limitations
One of the limitations of this study is the lack of recall of fruit and vegetable consumption during the last six months until the time of data collection, which might have affected the accurate calculation of the mean consumption of fruits and vegetables in the two groups of participants. Furthermore, strict adherence to the inclusion and exclusion criteria made it difficult to select the target group. Moreover, keeping the study groups together during the study to comply with the inclusion criteria required high accuracy, leading to the withdrawal of the participants in the second stage of the study. One of the strengths of the current study was the variety of direct and indirect educational interventions, which provided an opportunity for all participants to benefit from educational materials according to their working conditions.

Conclusion
Based on the results of this study, the consumption of fruits and vegetables is only effective in improving the levels of total cholesterol and LDL-C, but not in lowering triglyceride and HDL-C levels. Therefore, influencing factors, such as the duration of fruit and vegetable consumption, as well as the time required to monitor their effect, should be more closely examined.

Acknowledgments: The authors are thankful to the Research Deputy of Isfahan University of Medical Sciences, for its financial support. The authors also thank all participants of the study.
Ethical Permission: This study was reviewed and approved by the Ethics Committee of Isfahan University of Medical Sciences (No.IR. MUI.REC.1398.465).
Conflicts of Interests: There are no conflicts of interests.
Authors’ Contribution: Khatti Dizabadi F (First Author), Methodologist/Main Researcher (25%); Makvandi Z (Second Author), Introduction Writer/Discussion writer (25%); Yazdani Charati J (Third Author), Assistant Researcher/Statistical Analyst (25%); Mostafavi F (Forth author), Assistant Researcher/Discussion writer (25%)
Funding/Support: This study was funded by the Isfahan University of Medical Sciences, Isfahan, Iran (Grant No. 398521).
  1. 1. Abas R, Othman F, Then Z.C.J.E.J. Effect of Momordica charantia fruit extract on vascular complication in type 1 diabetic rate,EXCLI. 2015; 179,J14.
    2. Boren JChpman M.J, Krauss R.M, Packard C.I, Bentzon J.F, Binder C.I,et al. Low- density lipoproteins cause atherosclerotic cardiovascular isease:pathophysiological, genetic, and therapeutic insights: a consensus statement from the European Atherosclerosis Society Consensus Panel, Eur.Heart J. 2020;1(24)2313-2330.
    3. Hedayatnia M, Asadi Z, Zare-Feyzabadi R, Yaghooti-Khorasani M, Ghzizadeh H, Ghaffarian-Zirak R, et al.Dyslipidemia and cardiovascular disease risk among the Mashhad study population, Lipids. Health. Dis. 2020;19(1):42.
    4. Aikawa M, Libby P. The vulnerable atherosclerotic plaque: pathogenesis and therapeutic approach. Cardiovasc Pathol. 2004;14(3):125-38
    5. Kheirandish M, Asgari S, Lotfaliany M,Bozorgmanesh M,Saadat N,Tohidi M, " et al" . Secular trends in serumlipid levels of a Middle Eastern adult population; 10 years follow up in Tehran lipid and glucose study. Lipids Health Dis 2014 Jan 23; 13: 20. Doi: 10. 1186/1476 – 511X – 13- 20.
    6. Tabrizi JS, Nikniaz L, Sadeghi bazargani H, Farahbakhsh M, Nikniaz Z, Abbasalizad-Farhangi M, et al. Prevalence of Dyslipidemia in Urban and Rural Areas of the Northwest of Iran: The Sociodemographic, Dietary and Psychological Determinants. Iran J Public Health. 2019;48(5):925-33.
    7. Tabary M, Cheraghian B, Mohammadi Z, Rahimi Z, Naderian MR, Danehchin L, et al. Association of anthropometric indices with cardiovascular disease risk factors among adults: a study in Iran. European Journal of Cardiovascular Nursing. 2020;https://doi.org/10.1093/eurjcn/zvaa007
    8. Eriksen A, Tillin T, O’Connor L, Brage S, Hughes A, Mayet J, McKeigue P, Whincup P, Chaturvedi N, Forouhi NG. The impact of health behaviours on incident cardiovascular disease in Europeans and South Asians–a prospective analysis in the UK SABRE study. PloS one. 2015 Mar 2; 10(3):e0117364.
    9. Aune D, Giovannucci E, Boffetta P, Fadnes LT, Keum N, Norat T, Greenwood DC, Riboli E, Vatten LJ, Tonstad S. Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality—a systematic review and dose-response meta-analysis of prospective studies. International journal of epidemiology. 2017 Jun 1; 46(3):1029-56. doi:10.1093/ije/dyw319
    10. Zhan J, Liu YJ, Cai LB, Xu FR, Xie T, He QQ. Fruit and vegetable consumption and risk of cardiovascular disease: A meta-analysis of prospective cohort studies. Critical reviews in food science and nutrition. 2017 May 24; 57(8):1650-63.
    11. Wu Y, Zhang D, Jiang X, Jiang W. Fruit and vegetable consumption and risk of type 2 diabetes mellitus: a dose-response meta-analysis of prospective cohort studies. Nutr Metab Cardiovasc Dis. 2015 Feb 1; 25(2):140-7.
    12. Wang Y, Li F, Wang Z, Qiu T, Shen Y, Wang M. Fruit and vegetable consumption and risk of lung cancer: a dose–response meta-analysis of prospective cohort studies. Lung cancer. 2015 May 1; 88(2):124-30.
    13. Shin JY, Kim JY, Kang HT, Han KH, Shim JY. Effect of fruits and vegetables on metabolic syndrome: a systematic review and meta-analysis of randomized controlled trials. International journal of food sciences and nutrition. 2015 May 19; 66(4):416-25.
    14. World Health Organization. Global Health Risks. Mortality and burden of disease attributable to selected major risks. Geneva: WHO; 2009.
    15. Slavin JL, Lloyd B. Health benefits of fruits and vegetables. Advances in nutrition. 2012 Jul; 3(4):506-16.
    16. Deng GF, Lin X, Xu XR, Gao LL, Xie JF, Li HB. Antioxidant capacities and total phenolic contents of 56 vegetables. Journal of functional foods. 2013 Jan 1; 5(1):260-6.
    17. Li AN, Li S, Li HB, Xu DP, Xu XR, Chen F. Total phenolic contents and antioxidant capacities of 51 edible and wild flowers. Journal of functional foods. 2014 Jan 1; 6:319-30.
    18. Li S, Li SK, Gan RY, Song FL, Kuang L, Li HB. Antioxidant capacities and total phenolic contents of infusions from 223 medicinal plants. Industrial Crops and Products. 2013 Nov 1; 51:289-98.
    19. Zhou Y, Li Y, Zhou T, Zheng J, Li S, Li HB. Dietary natural products for prevention and treatment of liver cancer. Nutrients. 2016 Mar 10; 8(3):156.
    20. Li AN, Li S, Zhang YJ, Xu XR, Chen YM, Li HB. Resources and biological activities of natural polyphenols. Nutrients. 2014 Dec 22; 6(12):6020-47.
    21. Mirmiran P, Noori N, Zavareh MB, Azizi F. Fruit and vegetable consumption and risk factors for cardiovascular disease. Metabolism. 2009 Apr 1; 58(4):460-8.
    22. Radhika G, Sudha V, Sathya RM, Ganesan A, Mohan V. Association of fruit and vegetable intake with cardiovascular risk factors in urban south Indians. British Journal of Nutrition. 2008 Feb;99(2):398-405.
    23. Dragsted LO, Krath B, Ravn-Haren G, et al. Biological effects of fruit and vegetables. Proc Nutr Soc 2006; 65:61-67.
    24. Penczynski KJ, Remer T, Herder C, Kalhoff H, Rienks J, Markgraf DF, Roden M, Buyken AE. Habitual flavonoid intake from fruit and vegetables during adolescence and serum lipid levels in early adulthood: a prospective analysis. Nutrients. 2018 Apr 14; 10(4):488. doi: 10.3390/nu10040488
    25. Palmer FM, Nieman DC, Henson DA, McAnulty SR, McAnulty L, Swick NS, Utter AC, Vinci DM, Morrow JD. Influence of vitamin C supplementation on oxidative and salivary IgA changes following an ultramarathon. European journal of applied physiology. 2003 Mar; 89:100-7.
    26. Moser MA, Chun OK. Vitamin C and heart health: a review based on findings from epidemiologic studies. J. Mol. Sci. 2016 Aug 12; 17(8):1328.Doi: 10.3390/ijms17081328.
    27. Mobley AR, Jones J.M, Rodriguez J, Slavin J, Zelman K.M.Identifying practical solutions to meet America’sfiber needs, in: Proceeding from the food & fiber summit, Multidisciplinary Digital Publishing Institute, 2014.A1.
    28. Alshaikh MK, Rawaf S, Quezada-Yamamoto H. Cardiovascular risk and fruit and vegetable consumption among women in KSA; A cross-sectional study. Journal of Taibah University medical sciences. 2018 Oct 1; 13(5):444-51.
    29. Samavat T, Hojjatzadeh A, Shams M, Afghami A, Mahdavi A, Bashti SH and etal. Ways of prevention and control of cardiovascular diseases, especially for government employees. Ministry of Health and Medical Education, Department of Health, Noncommunicable Disease Unit. Javan.Tehran:2011.
    30. Kushida O, Murayama N. Effects of environmental intervention in workplace cafeterias on vegetable consumption by male workers. Journal of nutrition education and behavior. 2014 Sep 1; 46(5):350-8.
    31. Hutchinson AD, Howlett G, Wilson C. Increasing employees' fruit consumption through access and peer support at work. Food and Nutrition Sciences. 2013 Oct 1; 4(10A):88-95
    32. Pescud M, Waterworth P, Shilton T, Teal R, Slevin T, Ledger M, Lester L , Rosenberg M. A healthier workplace? Implementation of fruit boxes in the workplace.Health Education Journal. 2016; 75(7): 843– 854.
    33. Lake AA, Smith SA, Bryant CE, Alinia S, Brandt K, Seal CJ, Tetens I. Exploring the dynamics of a free fruit at work intervention. BMC public health. 2016 Dec; 16(1):1-10.DOI 10.1186/s12889-016-3500-4.
    34. Allan J, Querstret D, Banas K, de Bruin M. Environmental interventions for altering eating behaviours of employees in the workplace: a systematic review. Obesity Reviews. 2017 Feb; 18(2):214-26.
    35. Karkhah A, Karkhah MR, Ghadimi R. An Overview on the Role of Nutrition and Food Groups in the Prevention of Cardiovascular Diseases. J Babol Univ Med Sci. 2017; 19 ( 3): 66 -73.
    36. Hosseinpour- Niazi S, Bakhshi B, Mirmiran P, Azizi F. Interactions between Weight Change and Fruit and Vegetable Intake in the Incidence of Metabolic Syndrome: The Tehran Lipid and Glucose Study. Iranian J of Endo and Metab. 2020; 22 (4):295-305
    37. Bobeuf F, Labonte M, Dionne IJ, Khalil A. Combined effect of antioxidant supplementation and resistance training on oxidative stress markers, muscle and body composition in an elderly population. The journal of nutrition, health & aging. 2011; 15(10):883-9.
    38. Malekahmadi M , Alavi Naeini AM, Djazayery A , Aghaye ghazvini MR. The Combined Effect of Vitamins E and C Supplementation on the Lipid Profiles of Elderly Residents in Isfahan. Iranian J of Nutr Sci & Food Tech.2015;10(2): 37-46
    39. Montazerifar FHM, Karajibani M, Dikshit M. Effect of antioxidant vitamins on lipid profile and total antioxidant capacity in hemodialysis patients RMJ. 2010; 35(2):120- 23.
    40. Khatti-Dizabadi F, Yazdani-Charati J, Amani R, Mostafavi F. Investigating the predictive power of constructs of extended Pender's health promotion model and some background factors in fruit and vegetable consumption behavior among government employees. Journal of Education and Health Promotion. 2022; 11:91. DOI: 10.4103/jehp.jehp_214_21.
  2. Abas R, Othman F, Then ZCJEJ. Effect of Momordica charantia fruit extract on vascular complication in type 1 diabetic rate. EXCLI J. 2015;14:179-89. [Link]
  3. Boren J, Chpman MJ, Krauss RM, Packard CI, Bentzon JF, Binder CI, et al. Low- density lipoproteins cause atherosclerotic cardiovascular isease:pathophysiological, genetic, and therapeutic insights: A consensus statement from the European Atherosclerosis Society Consensus Panel. Eur Heart J. 2020;1(24)2313-2330. [Link] [DOI:10.1093/eurheartj/ehz962]
  4. Hedayatnia M, Asadi Z, Zare-Feyzabadi R, Yaghooti-Khorasani M, Ghzizadeh H, Ghaffarian-Zirak R, et al. Dyslipidemia and cardiovascular disease risk among the Mashhad study population. Lipids Health Dis. 2020;19(1):42. [Link] [DOI:10.1186/s12944-020-01204-y]
  5. Aikawa M, Libby P. The vulnerable atherosclerotic plaque: Pathogenesis and therapeutic approach. Cardiovasc Pathol. 2004;14(3):125-38 [Link] [DOI:10.1016/S1054-8807(04)00004-3]
  6. Kheirandish M, Asgari S, Lotfaliany M, Bozorgmanesh M, Saadat N, Tohidi M, et al. Secular trends in serumlipid levels of a Middle Eastern adult population; 10 years follow up in Tehran lipid and glucose study. Lipids Health Dis. 2014; 13:20. [Link] [DOI:10.1186/1476-511X-13-20]
  7. Tabrizi JS, Nikniaz L, Sadeghi bazargani H, Farahbakhsh M, Nikniaz Z, Abbasalizad-Farhangi M, et al. Prevalence of dyslipidemia in urban and rural areas of the northwest of Iran: The sociodemographic, dietary and psychological determinants. Iran J Public Health. 2019;48(5):925-33. [Link] [DOI:10.18502/ijph.v48i5.1810]
  8. Tabary M, Cheraghian B, Mohammadi Z, Rahimi Z, Naderian MR, Danehchin L, et al. Association of anthropometric indices with cardiovascular disease risk factors among adults: A study in Iran. Eur J Cardiovasc Nurs. 2020;20(4):358-66. [Link] [DOI:10.1093/eurjcn/zvaa007]
  9. Eriksen A, Tillin T, O'Connor L, Brage S, Hughes A, Mayet J, et al. The impact of health behaviours on incident cardiovascular disease in Europeans and South Asians- a prospective analysis in the UK SABRE study. PloS One. 2015;10(3):e0117364. [Link] [DOI:10.1371/journal.pone.0117364]
  10. Aune D, Giovannucci E, Boffetta P, Fadnes LT, Keum N, Norat T, et al. Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-a systematic review and dose-response meta-analysis of prospective studies. Int J Epidemiol. 2017;46(3):1029-56. [Link] [DOI:10.1093/ije/dyw319]
  11. Zhan J, Liu YJ, Cai LB, Xu FR, Xie T, He QQ. Fruit and vegetable consumption and risk of cardiovascular disease: A meta-analysis of prospective cohort studies. Crit Rev Food Sci Nutr. 2017;57(8):1650-63. [Link] [DOI:10.1080/10408398.2015.1008980]
  12. Wu Y, Zhang D, Jiang X, Jiang W. Fruit and vegetable consumption and risk of type 2 diabetes mellitus: A dose-response meta-analysis of prospective cohort studies. Nutr Metab Cardiovasc Dis. 2015;25(2):140-7. [Link] [DOI:10.1016/j.numecd.2014.10.004]
  13. Wang Y, Li F, Wang Z, Qiu T, Shen Y, Wang M. Fruit and vegetable consumption and risk of lung cancer: a dose-response meta-analysis of prospective cohort studies. Lung cancer. 2015;88(2):124-30. [Link] [DOI:10.1016/j.lungcan.2015.02.015]
  14. Shin JY, Kim JY, Kang HT, Han KH, Shim JY. Effect of fruits and vegetables on metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials. Int J Food Sci Nutr. 2015;66(4):416-25. [Link] [DOI:10.3109/09637486.2015.1025716]
  15. World Health Organization. Global Health Risks. Mortality and burden of disease attributable to selected major risks [Internet]. Geneva: WHO; 2009- [cited 2023 January 20]. Available from: https://apps.who.int/iris/handle/10665/44203. [Link]
  16. Slavin JL, Lloyd B. Health benefits of fruits and vegetables. Adv Nutr. 2012;3(4):506-16. [Link] [DOI:10.3945/an.112.002154]
  17. Deng GF, Lin X, Xu XR, Gao LL, Xie JF, Li HB. Antioxidant capacities and total phenolic contents of 56 vegetables. J Functional Foods. 2013; 5(1):260-6. [Link] [DOI:10.1016/j.jff.2012.10.015]
  18. Li AN, Li S, Li HB, Xu DP, Xu XR, Chen F. Total phenolic contents and antioxidant capacities of 51 edible and wild flowers. J Functional Foods. 2014;6:319-30. [Link] [DOI:10.1016/j.jff.2013.10.022]
  19. Li S, Li SK, Gan RY, Song FL, Kuang L, Li HB. Antioxidant capacities and total phenolic contents of infusions from 223 medicinal plants. Industrial Crops Prod. 2013;51:289-98. [Link] [DOI:10.1016/j.indcrop.2013.09.017]
  20. Zhou Y, Li Y, Zhou T, Zheng J, Li S, Li HB. Dietary natural products for prevention and treatment of liver cancer. Nutrients. 2016;8(3):156. [Link] [DOI:10.3390/nu8030156]
  21. Li AN, Li S, Zhang YJ, Xu XR, Chen YM, Li HB. Resources and biological activities of natural polyphenols. Nutrients. 2014;6(12):6020-47. [Link] [DOI:10.3390/nu6126020]
  22. Mirmiran P, Noori N, Zavareh MB, Azizi F. Fruit and vegetable consumption and risk factors for cardiovascular disease. Metabolism. 2009;58(4):460-8. [Link] [DOI:10.1016/j.metabol.2008.11.002]
  23. Radhika G, Sudha V, Sathya RM, Ganesan A, Mohan V. Association of fruit and vegetable intake with cardiovascular risk factors in urban south Indians. Br J Nutr. 2008;99(2):398-405. [Link] [DOI:10.1017/S0007114507803965]
  24. Dragsted LO, Krath B, Ravn-Haren G, Vogel UB, Vinggaard AM, Jensen PB, et al. Biological effects of fruit and vegetables. Proc Nutr Soc 2006;65:61-7. [Link] [DOI:10.1079/PNS2005480]
  25. Penczynski KJ, Remer T, Herder C, Kalhoff H, Rienks J, Markgraf DF, et al. Habitual flavonoid intake from fruit and vegetables during adolescence and serum lipid levels in early adulthood: A prospective analysis. Nutrients. 2018;10(4):488. [Link] [DOI:10.3390/nu10040488]
  26. Palmer FM, Nieman DC, Henson DA, McAnulty SR, McAnulty L, Swick NS, et al. Influence of vitamin C supplementation on oxidative and salivary IgA changes following an ultramarathon. Eur J Appl Physiol. 2003;89(1):100-7. [Link] [DOI:10.1007/s00421-002-0756-4]
  27. Moser MA, Chun OK. Vitamin C and heart health: A review based on findings from epidemiologic studies. J Mol Sci. 2016;17(8):1328. [Link] [DOI:10.3390/ijms17081328]
  28. Mobley AR, Jones JM, Rodriguez J, Slavin J, Zelman KM. Identifying practical solutions to meet America'sfiber needs, in: Proceeding from the food & fiber summit. Nutrients. 2014;6(7): 2540-51. [Link] [DOI:10.3390/nu6072540]
  29. Alshaikh MK, Rawaf S, Quezada-Yamamoto H. Cardiovascular risk and fruit and vegetable consumption among women in KSA; A cross-sectional study. J Taibah Univ Med Sci. 2018;13(5):444-51. [Link] [DOI:10.1016/j.jtumed.2018.06.001]
  30. Samavat T, Hojjatzadeh A, Shams M, Afghami A, Mahdavi A, Bashti SH, et al. Ways of prevention and control of cardiovascular diseases, especially for government employees. Tehran: Javan; 2011. [Persian] [Link]
  31. Kushida O, Murayama N. Effects of environmental intervention in workplace cafeterias on vegetable consumption by male workers. J Nutr Educ Behav. 2014;46(5):350-8. [Link] [DOI:10.1016/j.jneb.2014.05.001]
  32. Hutchinson AD, Howlett G, Wilson C. Increasing employees' fruit consumption through access and peer support at work. Food Nutr Sci. 2013;4(10A):88-95 [Link] [DOI:10.4236/fns.2013.410A013]
  33. Pescud M, Waterworth P, Shilton T, Teal R, Slevin T, Ledger M, et al. A healthier workplace? Implementation of fruit boxes in the workplace. Health Educ J. 2016;75(7):843-54. [Link] [DOI:10.1177/0017896916629817]
  34. Lake AA, Smith SA, Bryant CE, Alinia S, Brandt K, Seal CJ, et al. Exploring the dynamics of a free fruit at work intervention. BMC Public Health. 2016;16(1):1-10. [Link] [DOI:10.1186/s12889-016-3500-4]
  35. Allan J, Querstret D, Banas K, de Bruin M. Environmental interventions for altering eating behaviours of employees in the workplace: A systematic review. Obes Rev. 2017;18(2):214-26. [Link] [DOI:10.1111/obr.12470]
  36. Karkhah A, Karkhah MR, Ghadimi R. An overview on the role of nutrition and food groups in the prevention of cardiovascular diseases. J Babol Univ Med Sci. 2017;19(3):66-73. [Persian] [Link]
  37. Hosseinpour Niazi S, Bakhshi B, Mirmiran P, Azizi F. Interactions between weight change and fruit and vegetable intake in the incidence of metabolic syndrome: The Tehran lipid and glucose study. IJEM. 2020;22(4):295-305. [Persian] [Link]
  38. Bobeuf F, Labonte M, Dionne IJ, Khalil A. Combined effect of antioxidant supplementation and resistance training on oxidative stress markers, muscle and body composition in an elderly population. J Nutr Health Aging. 2011;15(10):883-9. [Link] [DOI:10.1007/s12603-011-0097-2]
  39. Malekahmadi M, Alavi Naeini AM, Djazayery A, Aghaye ghazvini MR. The combined effect of vitamins E and C supplementation on the lipid profiles of elderly residents in Isfahan. Iran J Nutr Sci Food Tech. 2015;10(2):37-46. [Persian] [Link]
  40. Montazerifar FHM, Karajibani M, Dikshit M. Effect of antioxidant vitamins on lipid profile and total antioxidant capacity in hemodialysis patients. RMJ. 2010;35(2):120-3. [Link]
  41. Khatti-Dizabadi F, Yazdani-Charati J, Amani R, Mostafavi F. Investigating the predictive power of constructs of extended Pender's health promotion model and some background factors in fruit and vegetable consumption behavior among government employees. J Educ Health Promot. 2022;11:91. [Link] [DOI:10.1017/jns.2021.90]
Health Education and Health Promotion
Volume 11, Issue 3
Autumn 2023
Pages 365-371