Effect of linoleic and oleic acids on blood pressure, blood viscosity, and erythrocyte cation transport.

Abstract

It has been proposed that dietary linoleic acid lowers blood pressure (BP) by being converted to arachidonic acid and prostanoids of the two-ene series. We tested the effects of linoleic acid on plasma arachidonic acid, blood pressure, blood viscosity, and RBC cation transport. Oleic acid, the major dietary monounsaturated fat and which is not a prostanoid precursor, was used as a control. Seventeen adults consumed 23 g/d of linoleic acid or oleic acid provided by genetic variants of safflower seed, each for 4 weeks in a double-blind crossover design. Linoleic and oleic acids were enriched significantly in the plasma cholesteryl esters, phospholipids and triglycerides during the respective periods of supplementation but there was no increase in arachidonate. Mean BP was 116.1/76.8 during ingestion of oleic and 113.6/74.6 during ingestion of linoleic acid (p = 0.09 systolic, p = 0.12 diastolic). The power of the study was over 75% for detecting a significant (p less than 0.05) effect of 4 mm Hg in systolic BP or diastolic BP. Whole blood and plasma viscosity, and RBC Li/Na countertransport, Na/K cotransport, and Na pump systems (Vmax) were unchanged during the protocol. Therefore, variations in dietary linoleic or oleic acids are unlikely to have major effects on BP or on several membrane-dependent erythrocyte functions related to hypertension.

The Li+-Na+ exchange and Na+-K+-Cl- cotransport systems in essential hypertension.

“…In addition, we have observed that diet supplementation with oleic and linoleic acid did not reveal changes in this transport system. 27 On the basis of these findings, we conclude that dietary manipulations do not affect RBC Li + -Na + countertransport.…”

Lack of effect on blood pressure by low fat diets with different fatty acid compositions

“…[26][27][28][29] In contrast to these findings, several studies have failed to show an effect on BP by increased intake of linoleic acid. 5,[30][31][32][33] In two studies with study periods of 6-8 months, a reduction of BP was observed during a low-fat, high-fibre diet 34 and an American Heart Association Step I diet with moderate fat reduction and equal amounts of SAFA and PUFA. 35 Trials with n-3 fatty acids have indicated that very high intakes of fatty fish and supplementation with fish oil concentrates decrease both SBP and diastolic BP (DBP).…”

Effet-dose de l’acide oléique alimentaire. Cet acide est-il conditionnellement essentiel ?

“…Son impact est principalement étudié dans le cadre des maladies cardiovasculaires, de la régulation des LDL plasmatiques, de leur contenu en cholestérol et de leur oxydabilité [3], éventuellement lors d'un traitement hypocalorique [4]. Il intervient aussi dans la modulation de la pression et de la viscosité sanguines et, enfin, du transport des cations dans les érythrocytes [5]. L'acide oléique pourrait contribuer à un bon contrôle de l'hypertriglycéridémie chez le rat diabétique [6], il potentialise l'effet de la perte de poids qui diminue le risque cardiovasculaire chez les patients obèses et diabétiques [7].…”