Abstract
Context:
Hypertension is defined as systolic blood pressure above 140 mmHg or diastolic blood pressure greater than 90 mmHg or both. Hypertension can be controlled by diet containing an adequate amount of phytochemicals.Evidence Acquisition:
The article is based on non-systematic literature searches in PubMed, Ovid and ScienceDirect.Results:
Hypertension is one of the major chronic diseases, which can affect people around the world. Today's DASH diet (dietary approach to stop hypertension) is used to reduce and control blood pressure. The diet containing plenty of fruits, vegetables, nuts and whole grains including nutrients such as vitamins and minerals and non-nutrient elements is called phytochemical. Phytochemicals are materials at very low concentrations, which affect the expression of many genes, including transcription factors AP-1, NF-KappaB, SREBPs, PPARs and their cellular metabolism and gene regulation; also have antioxidant properties and antihypertensive effects. Moreover, increased intake of phytochemicals is associated with decreased mortality rate from cardiovascular diseases, stroke and injuries secondary to hypertension. Possible mechanisms of action of phytochemicals to reduce blood pressure include inhibition of angiotensin-converting enzyme and inactivation bradikinin and regulation of bioavailability of nitrous oxide.Conclusions:
In conclusion, based on the results, increased intake of phytochemicals in daily diet is associated with decreased risk of mortality from coronary heart disease, stroke and injuries secondary to hypertension.Keywords
1. Context
Hypertension or high blood pressure is defined as systolic blood pressure of greater than 140 mmHg or diastolic blood pressure greater than 90 mmHg or both, affecting 11% of Iran population (1). Hypertension is the third risk factor for death from cardiovascular disease, together with LDL-C and smoking, which is called the silent killer (2, 3). Besides, hypertension is the major risk factor for stroke and renal dysfunction. Lowering the blood pressure, through dietary may decrease damage of hypertension. Epidemiological studies suggest that consumption of fruit, vegetables (4-8) and mineral water, water (9, 10) and tea may protect against high blood pressure (11-14). Vegetables, fruits and tea may decrease blood pressure due to phytochemicals (15, 16). Functional non-nutrient food factors (phytochemicals) are found in vegetables and fruits and are effective for health promotion and disease prevention (15-17).
2. Evidence Acquisition
The article was based on non-systematic literature searches in PubMed, Ovid and ScienceDirect.
3. Results
3.1. Phytochemical
Flavonoids, polyphenols and carotenoids are included in phytochemical database (15). This review summarizes the current evidence on the effect of phytochemical on blood pressure. High intake of fresh fruit and vegetable was associated with a low stroke mortality risk, which is probably attributed to preventing hypertension (18).
3.2. Flavonoids and Hypertension
Flavonoid compounds contain flavonols (quercetin, kaempferol and myricetin), flavones (apigenin, and lutelin) and isoflavones (coumestrol, daidzein, genistein and equol) (18).
Therefore, vegetarians had approximately 40% higher intake of flavonoids than non–vegetarians. Flavonoids are scavengers of free radicals such as superoxide anions and lipid proxy radicals and by preventing oxidation of LDL-C, because oxidized LDL is believed to be atherogenic. Therefore, flavonoids may decrease the formation of atherosclerotic plaques and reduce arterial stiffness, leaving arteries more responsive to the endogenous stimuli of vasodilation (5, 18).
The major dietary of flavonoid intake is black tea. Studies have shown that consumption of fruit, vegetable and tea (black and green) containing high amount of flavonoid may lead to lower blood pressure and may provide protection against coronary heart disease and stroke. It is possible that their antioxidant effect is responsible.
3.3. Poly Phenols and Hypertension
The Mediterranean diet is associated with greater longevity and quality of life in epidemiological studies, which is because of the abundance of fruits and vegetables containing high amounts of polyphenols. Several polyphenol-rich sources such as grape-derived products, cocoa, tea, soy, pomegranate and tomatoes have been shown to decrease blood pressure in hypertensive patients (6, 19-24). Polyphenol compounds include chlorogenic acid, caffeic acid, coumaric acid, gallic acid, quercetin, isorhamnetin, kaempferol, hesperetin, naringenin, phloretin, enterolactone and enterodiol (25). Recent studies suggest that chlorogenic acids as the main components of the polyphenol class in coffee, decrease the blood pressure (26). The hypotensive effects of chlorogenic acids were associated with nitric oxide, suppression of mRNA expression of NADOH oxidase, and improvement in endothelium-dependent vasodilation in the aorta (27, 28). Grassi et al. suggested that consumption of dark chocolate for 15 days reduced systolic blood pressure in healthy subjects as well as young and elderly hypertensive patients (29). Polyphenols decrease blood pressure by increasing endothelial nitric oxide bioavailability via their antioxidant action and their capacity to activate vascular endothelial nitric oxide synthase.
3.4. Carotenoids and Hypertension
In the last years, it is known that excess reactive oxygen species (ROS), is associated to inflammation, growth and vasoconstriction contributing to vascular injury in many cardiovascular diseases such as hypertension, hyperlipidemia and diabetes (30, 31). ROS plays an important pathophysiological role in hypertension. Antioxidants such as carotenoids inhibit NAD(P)H oxides-driven generation of ROS, improve endothelial function, enhance nitric oxide (NO) generation and reduce blood pressure in hypertensive patients (30). Astaxanthin, an oxi-carotenoid has antihypertensive effect by normalization of sensitivity of adrenoreceptor sympathetic pathway, decrease in oxidative stress and improvement in NO bioavailability (30). Lycopene, a carotenoid without pro-vitamin A, is red pigment in tomatoes and watermelon. High lycopene consumption has been associated with a decrease in blood pressure (32, 33). A Meta-analysis performed on the effect of lycopene on systolic blood pressure of all trails suggested a significant blood pressure reducing effect (-5. 60 + 5.26 mmHg), but no significant effect on diastolic blood pressure (34). Blood pressure lowering properties of lycopene have been attributed to the stimulation of nitric oxide production in the endothelium (34).
4. Discussion
Based on the results, increased intake of phytochemical in daily diet is associated with decreased risk of mortality in coronary heart diseases, stroke and damage secondary to hypertension. Therefore, it is emphasized to consume foods rich in phytochemical such as vegetables, fruits, nuts, tea and coffee, etc., in the diet to control and prevent hypertension.
Acknowledgements
References
-
1.
Ranjbar F, Akbarzade F, khaneshi M. The study oftype A personality in essential Hypertensionpatient. Medical Journal of Kordestan Universityof Medical Sciences. 2006;11:26-31.
-
2.
Kooshki A, Yaghoubifar MA, Behnam VHR. Relation between drinking water and blood pressure. Sabzevar J Medical Science. 2004;10(3):23-8.
-
3.
Kooshki A, Mohajeri N, Movahedi A. Prevalence of CVD Risk Factors related to diet in Patients Referring toModarres Hospital in Tehran in 1999. Sabzevar J Medical Science. 2004;10(2):17-22.
-
4.
Liu S, Manson JE, Lee IM, Cole SR, Hennekens CH, Willett WC, et al. Fruit and vegetable intake and risk of cardiovascular disease: the Women's Health Study. Am J Clin Nutr. 2000;72(4):922-8. [PubMed ID: 11010932].
-
5.
de Paula TP, Steemburgo T, de Almeida JC, Dall'Alba V, Gross JL, de Azevedo MJ. The role of Dietary Approaches to Stop Hypertension (DASH) diet food groups in blood pressure in type 2 diabetes. Br J Nutr. 2012;108(1):155-62. [PubMed ID: 22142820]. https://doi.org/10.1017/S0007114511005381.
-
6.
Alonso A, de la Fuente C, Martin-Arnau AM, de Irala J, Martinez JA, Martinez-Gonzalez MA. Fruit and vegetable consumption is inversely associated with blood pressure in a Mediterranean population with a high vegetable-fat intake: the Seguimiento Universidad de Navarra (SUN) Study. Br J Nutr. 2004;92(2):311-9. [PubMed ID: 15333163]. https://doi.org/10.1079/BJN20041196.
-
7.
Wang L, Manson JE, Gaziano JM, Buring JE, Sesso HD. Fruit and Vegetable Intake and the Risk of Hypertension in Middle-Aged and Older Women. American Journal of Hypertension. 2012;25(2):180-9. https://doi.org/10.1038/ajh.2011.186.
-
8.
Kooshki A, Golafrooz Shahri M. Assessment of macro and micro nutrients on blood pressure in diabetics patients. Ofogh Danesh. 2004;11(1):34-7.
-
9.
Kooshki A, Aminpour A, Azar M, Kalantari N, Ardakani H. The effect of drinking damavand mineral water on sodium,potassium, magnesium and calcium cations in men with hpertension. Sabzevar J Medical Science. 2003;9(4):31-8.
-
10.
Kooshki A, Aminpour A, Azar M. Influence of type and duration of water intake on blood pressure in hypertensive men. Ofogh Danesh. 2007;12(2):50-4.
-
11.
Yang YC, Lu FH, Wu JS, Wu CH, Chang CJ. The protective effect of habitual tea consumption on hypertension. Arch Intern Med. 2004;164(14):1534-40. [PubMed ID: 15277285]. https://doi.org/10.1001/archinte.164.14.1534.
-
12.
Giday A, Tadesse B. Prevalence and determinants of hypertension in rural and urban areas of southern Ethiopia. Ethiop Med J. 2011;49(2):139-47. [PubMed ID: 21796914].
-
13.
Sae-tan S, Grove KA, Lambert JD. Weight control and prevention of metabolic syndrome by green tea. Pharmacol Res. 2011;64(2):146-54. [PubMed ID: 21193040]. https://doi.org/10.1016/j.phrs.2010.12.013.
-
14.
Kurita I, Maeda-Yamamoto M, Tachibana H, Kamei M. Antihypertensive effect of Benifuuki tea containing O-methylated EGCG. J Agric Food Chem. 2010;58(3):1903-8. [PubMed ID: 20078079]. https://doi.org/10.1021/jf904335g.
-
15.
Dauchet L, Amouyel P, Hercberg S, Dallongeville J. Fruit and vegetable consumption and risk of coronary heart disease: a meta-analysis of cohort studies. J Nutr. 2006;136(10):2588-93. [PubMed ID: 16988131].
-
16.
Seymour EM, Singer AA, Bennink MR, Parikh RV, Kirakosyan A, Kaufman PB, et al. Chronic intake of a phytochemical-enriched diet reduces cardiac fibrosis and diastolic dysfunction caused by prolonged salt-sensitive hypertension. J Gerontol A Biol Sci Med Sci. 2008;63(10):1034-42. [PubMed ID: 18948553].
-
17.
Melby MK, Murashima M, Watanabe S. Phytochemical intake and relationship to past health history in Japanese women. Biofactors. 2004;22(1-4):265-9. [PubMed ID: 15630295].
-
18.
Moline J, Bukharovich IF, Wolff MS, Phillips R. Dietary flavonoids and hypertension: is there a link? Med Hypotheses. 2000;55(4):306-9. [PubMed ID: 11000057]. https://doi.org/10.1054/mehy.2000.1057.
-
19.
Cassidy A, O'Reilly EJ, Kay C, Sampson L, Franz M, Forman JP, et al. Habitual intake of flavonoid subclasses and incident hypertension in adults. Am J Clin Nutr. 2011;93(2):338-47. [PubMed ID: 21106916]. https://doi.org/10.3945/ajcn.110.006783.
-
20.
Jouad H, Lacaille-Dubois MA, Lyoussi B, Eddouks M. Effects of the flavonoids extracted from Spergularia purpurea Pers. on arterial blood pressure and renal function in normal and hypertensive rats. Journal of Ethnopharmacology. 2001;76(2):159-63. https://doi.org/10.1016/s0378-8741(01)00209-4.
-
21.
Schini-Kerth VB, Auger C, Etienne-Selloum N, Chataigneau T. Polyphenol-induced endothelium-dependent relaxations role of NO and EDHF. Adv Pharmacol. 2010;60:133-75. [PubMed ID: 21081218]. https://doi.org/10.1016/B978-0-12-385061-4.00006-4.
-
22.
Stoclet JC, Chataigneau T, Ndiaye M, Oak MH, El Bedoui J, Chataigneau M, et al. Vascular protection by dietary polyphenols. Eur J Pharmacol. 2004;500(1-3):299-313. [PubMed ID: 15464042]. https://doi.org/10.1016/j.ejphar.2004.07.034.
-
23.
Nicholson SK, Tucker GA, Brameld JM. Effects of dietary polyphenols on gene expression in human vascular endothelial cells. Proc Nutr Soc. 2008;67(1):42-7. [PubMed ID: 18234130]. https://doi.org/10.1017/S0029665108006009.
-
24.
Medina-Remon A, Zamora-Ros R, Rotches-Ribalta M, Andres-Lacueva C, Martinez-Gonzalez MA, Covas MI, et al. Total polyphenol excretion and blood pressure in subjects at high cardiovascular risk. Nutr Metab Cardiovasc Dis. 2011;21(5):323-31. [PubMed ID: 20167460]. https://doi.org/10.1016/j.numecd.2009.10.019.
-
25.
Ghosh D, Scheepens A. Vascular action of polyphenols. Mol Nutr Food Res. 2009;53(3):322-31. [PubMed ID: 19051188]. https://doi.org/10.1002/mnfr.200800182.
-
26.
Mennen LI, Sapinho D, Ito H, Bertrais S, Galan P, Hercberg S, et al. Urinary flavonoids and phenolic acids as biomarkers of intake for polyphenol-rich foods. Br J Nutr. 2006;96(1):191-8. [PubMed ID: 16870009].
-
27.
Suzuki A, Fujii A, Yamamoto N, Yamamoto M, Ohminami H, Kameyama A, et al. Improvement of hypertension and vascular dysfunction by hydroxyhydroquinone-free coffee in a genetic model of hypertension. FEBS Lett. 2006;580(9):2317-22. [PubMed ID: 16579992]. https://doi.org/10.1016/j.febslet.2006.03.047.
-
28.
Zhao Y, Wang J, Ballevre O, Luo H, Zhang W. Antihypertensive effects and mechanisms of chlorogenic acids. Hypertension Research. 2011;35(4):370-4. https://doi.org/10.1038/hr.2011.195.
-
29.
Grassi D, Desideri G, Necozione S, Lippi C, Casale R, Properzi G, et al. Blood pressure is reduced and insulin sensitivity increased in glucose-intolerant, hypertensive subjects after 15 days of consuming high-polyphenol dark chocolate. J Nutr. 2008;138(9):1671-6. [PubMed ID: 18716168].
-
30.
Monroy-Ruiz J, Sevilla MA, Carron R, Montero MJ. Astaxanthin-enriched-diet reduces blood pressure and improves cardiovascular parameters in spontaneously hypertensive rats. Pharmacol Res. 2011;63(1):44-50. [PubMed ID: 20868751]. https://doi.org/10.1016/j.phrs.2010.09.003.
-
31.
Kooshki A, Golafrooz Shahri M. Relationship between carotenoid intake and serum suger and lipids in diabetics type 2 patients. Ardebil J Med Scien. 2007;6(3):287-9.
-
32.
Tapiero H, Townsend DM, Tew KD. The role of carotenoids in the prevention of human pathologies. Biomed Pharmacother. 2004;58(2):100-10. [PubMed ID: 14992791]. https://doi.org/10.1016/j.biopha.2003.12.006.
-
33.
Paran E, Novack V, Engelhard YN, Hazan-Halevy I. The effects of natural antioxidants from tomato extract in treated but uncontrolled hypertensive patients. Cardiovasc Drugs Ther. 2009;23(2):145-51. [PubMed ID: 19052855]. https://doi.org/10.1007/s10557-008-6155-2.
-
34.
Ried K, Fakler P. Protective effect of lycopene on serum cholesterol and blood pressure: Meta-analyses of intervention trials. Maturitas. 2011;68(4):299-310. [PubMed ID: 21163596]. https://doi.org/10.1016/j.maturitas.2010.11.018.