Aging is associated with chronic low-grade increases in circulating levels of inflammatory molecules. A wide range of factors including obesity, metabolic syndrome, CVD, infection, smoking, genetic and declining function of sex hormones may contribute to the systemic low-grade increase in inflammatory activity in the elderly. Circulating TNFα is a good predictor of mortality in the frail elderly population and the oxidation of LDL can be a consequence of the secretion of cytokines and adhesion molecules during the inflammatory process. Dietary interventions may be good strategies to decrease pro-inflammatory activity and improve human health. It is well known that long-chain n-3 PUFA decrease the production of inflammatory cytokines. The aim of the present study was to compare the effect of T-Diet Plus^® v. a standard control diet on plasma concentrations of inflammatory markers and oxidized LDL (ox-LDL) in elderly patients feed total enteral nutrition (TEN) for 6 months.

Sixty-five patients aged 75 years feed TEN were divided into two groups (experimental and reference). The experimental group (n 32) was fed a new enteral formula, T-Diet Plus^® (Vegenat SA), that contained (mg/l) 75 EPA and 35 DHA. Reference group (n 33) was fed a standard enteral diet (Jevity^®, Abbot Laboratories) intended for nutrition in the elderly. At the end of the experimental period only sixteen patients from the T-Diet Plus^® group and twenty from the reference group remained in the study. The daily intake was 5459 (se 130) kJ, with no difference between groups. Cytokines (basal, 3 months and 6 months) were measured using a human serum adipokine (panel B) kit (LINCOplex™; Linco Research, St Charles, MO, USA) with the Luminex 200 System built on xMAP technology. Ox-LDL was determined using an ELISA kit (Biomedica Medizinprodukte GmbH & Co KG, Vienna, Austria) and the ultra-sensitive C-reactive protein (PCRus) with a turbidimetric immunoassay (Dade Behring Inc., Deerfield, IL, USA). Non-parametric tests were used for statistical analysis: Mann-Witney test was performed to evaluate differences between independent groups (P⩽0.05); Wilcoxon test was used to determine the effect of each diet after 3 or 6 months (mean values with unlike superscript letters were significantly different: P⩽0.05).

The results demonstrate that ox-LDL decreased after 6 months of monitored nutrition in both groups (P⩽0.05), with no differences between groups. No differences were found in other inflammatory markers, although both TNFα and IL-6 showed a tendency to decrease after 6 months, which is important considering that the patients were frail elderly with different pathologies.