Oleic acid serum phospholipid content is linked with the serum total- and LDL-cholesterol in elderly subjects

Increased dietary intake of the olive oil has been found to lower several cardiovascular risk factors. Aim of our study was to check if there is any link between the oleic acid (OL-18:1n9) serum phospholipid (SPL) content and some of these factors in subjects living relatively far from the Mediterranean region and in habitual conditions, i.e. without any dietary intervention.

The investigated group included 62 out-patients older than 51 yr. Serum lipids were measured using standard hospital laboratory methods, the LDL-cholesterol was calculated using Friedewald's formula. Gas chromatography was used for estimation of fatty acids (FA) in SPL, their values were calculated as relative percentages of all FA.

There was a statistically significant inverse correlation between the OL SPL content and the serum total cholesterol (TCHOL) in all 62 patients (r = -0.294; p = 0.020). Analogous correlation was marginally significant for the LDL (r = -0.245; p = 0.055). After a division into 2 groups based on the median of the OL, the group with OL higher than median had significantly lower both TCHOL and LDL (p = 0.014; p = 0.033, respectively). OL correlated positively with the alpha-linolenic acid (18:3n3; r = 0.281; p = 0.027) but inversely with the stearic acid (18:0; r = -0.303; p = 0.017).

The subjects with less OL in their SPL had higher TCHOL and LDL serum levels and also their fatty acid SPL spectrum showed some other features which may be characterized as undesirable. This is an independent argument emphasizing the need for enhancing OL dietary intake.