Effect of Dietary Fat Saturation on LDL Oxidation and Monocyte Adhesion to Human Endothelial Cells In Vitro

Abstract

Forty-two healthy men and women were subjected to four consecutive dietary periods differing in the fat content of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (n-6) [PUFA(n-6)] and (n-3) [PUFA(n-3)]. Plasma lipids, vitamin E, and in vitro LDL oxidation were examined during each period. Adhesion of human monocytes to cultured human endothelial cells was used as a functional test to identify differences in the biological properties of LDL from each dietary period. Consumption of an SFA-rich diet resulted in higher LDL cholesterol (4.06 +/- 0.85 mmol/L, P < .05) than did consumption of MUFA- (3.59 +/- 0.75 mmol/L), PUFA(n-6)- (3.44 +/- 0.77 mmol/L), or PUFA(n-3)- (3.31 +/- 0.8 mmol/L) rich diets. HDL cholesterol was lower during both PUFA-rich diets (1.24 +/- 0.28 and 1.27 +/- 0.28 mmol/L for n-6 and n-3, respectively) than during the SFA-(1.32 +/- 0.36 mmol/L) and MUFA- (1.32 +/- 0.34 mmol/L) rich diets. LDL resistance to copper-induced oxidation, expressed as lag time, was highest during the MUFA-rich diet (55.1 +/- 7.3 minutes) and lowest during the PUFA(n-3)- (45.3 +/- 7 minutes) and SFA- (45.3 +/- 6.4 minutes) rich diets. LDL induction of monocyte adhesion to endothelial cells was lower during the MUFA-rich diet than the other periods. The highest monocyte adhesion was obtained during the PUFA(n-3) and SFA dietary periods. In conclusion, an MUFA-rich diet benefits plasma lipid levels compared with an SFA-rich diet. Furthermore, this diet results in an increased resistance of LDL to oxidation and a lower rate of monocyte adhesion to endothelial cells than the other dietary fats examined.

Monounsaturated fats and immune function

“…It was reported that LDL-induced monocyte adhesion to endothelial cells was lower during the MUFA period than each of the others and that resistance of LDL to oxidation was greatest during the MUFA period (31). The authors suggest that the modulation of LDL fatty acid composition was responsible for the differences in adhesion and showed a significant negative correlation between monocyte adhesion to endothelial cells and the oleic acid content of LDL (31). Expression of adhesion molecules by either cell type was not measured, but it is possible that this too may have played some role in the decreased adhesion during the MUFA period.…”

“…In an interesting study by Mata et al (31), healthy men and women living in a religious community were subjected to four consecutive dietary periods (isocaloric) differing in the fat content of SFA, MUFA and n-3 and n-6 PUFA. It was reported that LDL-induced monocyte adhesion to endothelial cells was lower during the MUFA period than each of the others and that resistance of LDL to oxidation was greatest during the MUFA period (31). The authors suggest that the modulation of LDL fatty acid composition was responsible for the differences in adhesion and showed a significant negative correlation between monocyte adhesion to endothelial cells and the oleic acid content of LDL (31).…”

Monounsaturated fatty acids and immune function

“…Other evidence in humans suggests that a MUFA-rich diet may indeed affect the process of cellular adhesion. In an interesting study by Mata et al (1996) healthy men and women living in a religious community were subjected to four consecutive dietary periods (isocaloric) differing in the fat content of SFA, MUFA and n-3 and n-6 PUFA. It was reported that monocyte adhesion to endothelial cells was lower during the MUFA period than each of the others and that resistance of low-density lipoprotein (LDL) to oxidation was greatest during the MUFA period (Mata et al, 1996).…”

“…In an interesting study by Mata et al (1996) healthy men and women living in a religious community were subjected to four consecutive dietary periods (isocaloric) differing in the fat content of SFA, MUFA and n-3 and n-6 PUFA. It was reported that monocyte adhesion to endothelial cells was lower during the MUFA period than each of the others and that resistance of low-density lipoprotein (LDL) to oxidation was greatest during the MUFA period (Mata et al, 1996). The authors suggest that the modulation of LDL fatty acid composition was responsible for the differences in adhesion and showed a significant negative correlation between monocyte adhesion to endothelial cells and the oleic acid content of LDL (Mata et al, 1996).…”

“…It was reported that monocyte adhesion to endothelial cells was lower during the MUFA period than each of the others and that resistance of low-density lipoprotein (LDL) to oxidation was greatest during the MUFA period (Mata et al, 1996). The authors suggest that the modulation of LDL fatty acid composition was responsible for the differences in adhesion and showed a significant negative correlation between monocyte adhesion to endothelial cells and the oleic acid content of LDL (Mata et al, 1996). Similarly, Tsimikas et al (1999) prepared and oxidized LDL from Greek and American subjects, with differing intakes of olive oil, and assessed monocyte chemotaxis induced by oxidised LDL.…”