Fatty acid composition of serum lipids and its relation to diet in an elderly institutionalized population

Abstract

This study was conducted to determine the nutritional status with respect to fatty acids of 53 institutionalized elderly subjects (group A). Seven-day food records and biochemical determinations were used. The same protocol was applied to 25 healthy young adults (group B). The 1981 French Recommended Dietary Allowances were used to assess adequacy of intake. Total fat intake was found to be too high in both groups. Higher intakes of animal fats and saturated fatty acids and lower intakes of polyunsaturated fatty acids and linoleic acid were documented in group A than in group B. Elderly subjects exhibited decreased 18:2 omega 6 and 20:4 omega 6 in serum phospholipids and triglycerides. Other indicators of essential fatty acid status in group A differed from group B in the direction of deficiency (double-bond index [DBI], 0.93 +/- 0.01 vs 1.13 +/- 0.04, p less than 0.001; total omega 6, 25.07 +/- 0.46% vs 32.49 +/- 0.89%, p less than 0.001). These findings indicate that institutionalized elderly people are deficient in circulating essential fatty acids, which appears to be caused by both diet and metabolism.

Differences between polyunsaturated fatty acid status of non-institutionalised elderly women and younger controls: a bioconversion defect can be suspected

“…These data are in agreement with two studies in hospitalised patients (Holman, 1979;Lecerf et al, 1993), although lower percentages of 20:4 n-6 were observed in PL from elderly hospitalised patients in another study (Asciutti-Moura, 1988). The data of our study suggest that in our cohort of elderly women living at home, the 20:4 n-6 dietary supply compensated both the lower 18:2 n-6 intake and possibly some weakness of the n-6 biosynthetic pathway.…”

“…The same tendency was also detected in institutionalised patients: lower DHA percentages in PL were found in elderly patients than in a control group but, again, the difference was not signi®cant (Asciutti-Moura et al, 1988). Striking differences, however, appeared in the DHA EPAa18:3 n-3 ratio, which has been proposed to identify blocks in the n-3 pathway activity (Siguel & Maclure, 1987), and also in the DHAaEPA ratio, more speci®cally concerning the last steps of DHA biosynthesis.…”

“…As indicated above, lower percentages of 18:2 n-6 have been reported in elderly patients, but only in cohorts living in institutions or during hospitalisation (Holmann, 1979;Asciutti-Moura et al, 1988;Lecerf et al, 1993). The comparison of our population of elderly women living at home with data from the literature concerning institutionalised patients yielded interesting information.…”

“…In another study including 53 institutionalised elderly men and women ( ! 60 years), linoleic acid was found to be signi®cantly lower in TG and PL than in the control group (Asciutti-Moura et al, 1988). More recently, a reduction in linoleic acid was also reported in almost all the plasma lipid fractions of VLDL, LDL and HDL, but in a very small group of hospitalised elderly women (79 ± 90 y) (Lecerf et al, 1993).…”

The metabolism and availability of essential fatty acids in animal and human tissues

“…In humans, the liver desaturation activities are much lower than in rats Blond et al, 1981 Despite that, several studies have shown that few differences exist between elderly and young subjects with respect to the n-6 and n-3 fatty acid content of serum (Holman et al, 1979;Asciutti-Moura et al, 1988), erythrocyte (Driss et al, 1988) and platelet (Vericel et al, 1988) From these data, it is evident that longchain essential n-6 fatty acids were oxidized to C0 2 at a very low rate, much lower than the 'parents' 18:2n-6 and 18:3n-3. This is evidence that when provided as very longchain fatty acids, the EFA are required in lower amount in the diet than the precursors 18:2n-6 and 18:3n-3.…”