Effects of long-term intake of edible oils on hypertension... : Journal of Hypertension (original) (raw)
ORIGINAL PAPERS: DIET
Effects of long-term intake of edible oils on hypertension and myocardial and aortic remodelling in spontaneously hypertensive rats
Aguila, Marcia Barbosaa,b; Sa Silva, Suzana Pa; Pinheiro, Alessandra Ra; Mandarim-de-Lacerda, Carlos Albertoa
aLaboratory of Morphometry and Cardiovascular Morphology, State University of Rio de Janeiro, bDepartment of Applied Nutrition, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
Sponsorship: This study was supported by grants to the Laboratory of Morphometry and Cardiovascular Morphology from the Brazilian National Council CNPq and Rio de Janeiro Foundation FAPERJ.
Conflicts of interest: None.
Correspondence and requests for reprints to Marcia B. Aguila PhD, Laboratório de Morfometria e Morfologia Cardiovascular, Universidade do Estado do Rio de Janeiro, Centro Biomedico, Instituto de Biologia, Av 28 de Setembro, 87 (fds) – 20551-030 Rio de Janeiro, RJ, Brasil. Tel/fax: +55 21 2587 6416; e-mail: [email protected]
Received 22 May 2003 Revised 22 December 2003 Accepted 9 January 2004
Abstract
Background The nature of dietary lipid intake contributes to blood pressure control.
Objective To test whether different edible lipid compounds are either beneficial or harmful to blood pressure and cardiac and aortic structure.
Methods Six groups of 3-month-old male spontaneously hypertensive rats (n = 5) received different edible oils (fish, canola, palm, olive and soybean oils, 1.5 g/kg per day + 1 IU/ml vitamin E) or a placebo (water) by gavage for 13 weeks. Stereology was used to analyse left ventricular cardiomyocytes, intramyocardial vessels, connective tissue, aortic lamellae and tunica media smooth muscle cells.
Results Fish oil decreased blood pressure, and increases in blood pressure were prevented by both canola and palm oils. The cardiomyocyte and intramyocardial vessel indices were greater in the fish-, canola- and palm-oil groups and smaller in the soybean-oil, olive-oil and control groups; the opposite effects were found in interstitial connective tissue. The number of lamellae was smaller in the fish-oil group but greater in the soybean-oil, canola-oil, and olive-oil groups. Canola oil reduced aortic wall thickness, but palm oil did not. The number of smooth muscle cells was smaller in the groups given fish, canola and olive oils.
Conclusion The most beneficial cardiac and aortic structural effects occurred in the fish-oil group. Both canola oil and palm oil were also effective in reducing blood pressure, favouring myocardial remodelling, although they produced contrasting effects with regard to aorta wall structure. Soybean oil and olive oil had mild effects on myocardial and aortic structure.
© 2004 Lippincott Williams & Wilkins, Inc.