Consumption of nitrate-containing vegetables is inversely associated with hypertension in adults: a prospective investigation from the Tehran Lipid and Glucose Study.
BACKGROUND
There is growing evidence of the potential properties of nitrate-rich foods against development of hypertension (HTN) and vascular disease. In this study, we investigated the association of nitrate-containing vegetables (NCVs) with risk of HTN after 3 years of follow-up.


METHODS
This prospective study was conducted on 1546 non-hypertensive subjects, aged 20-70 years. Blood pressure was measured at baseline and after 3 years and HTN was defined by the Joint National Committee on prevention, detection, evaluation and treatment of high blood pressure criteria. Dietary intake was collected using a validated semi-quantitative food frequency questionnaire (FFQ). NCVs and high-, medium- and low-NCV subcategories were defined, and the odds of HTN after 3 years according to tertiles of NCV and NCV-category intake were estimated by logistic regression and adjusted for potential variables.


RESULTS
Mean age of participants was 38.0 ± 12.0 years at baseline and 57.0 % were women. Mean dietary intake of energy-adjusted NCV was 298.0 ± 177.3 g/day. After adjustment for total energy intake, fiber, sodium, potassium and processed meat, a significant inverse association was observed between NCV and the risk of HTN in the highest tertile category (odds ratio 0.63, 95 % confidence interval: 0.41-0.98, p for trend = 0.05). There was no significant association of 3 year risk of HTN across tertiles of low nitrate-, medium nitrate- and high-nitrate vegetables.


CONCLUSIONS
Higher dietary nitrate intake from vegetables sources may have a protective effect against development of HTN.
Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.|Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
Mahdieh
M
Golzarand
Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.|Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
Zahra
Z
Bahadoran
Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. parvin.mirmiran@gmail.com.|, No. 24, Parvaneh St, Yemen St, Chamran Exp, PO Box 19395-4763, Tehran, Islamic Republic of Iran. parvin.mirmiran@gmail.com.
Parvin
P
Mirmiran
Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.|Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
Azita
A
Zadeh-Vakili
Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
Fereidoun
F
Azizi
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004032:Diet; D005260:Female; D006801:Humans; D006973:Hypertension / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000008:administration & dosage*; D009569:Nitric Oxide / Q000502:physiology; D011446:Prospective Studies; D014675:Vegetables
D009566:Nitrates; D009569:Nitric Oxide
Blood pressure; Fruits and vegetables; Hypertension; Nitrate