Enteral feeding enriched with carotenoids normalizes the carotenoid status and reduces oxidative stress in long-term enterally fed patients.

BACKGROUND & AIMS: Circulating carotenoid levels decrease progressively in patients receiving long-term enteral tube feeding with carotenoid-free formulas. Low dietary intake and low blood levels of carotenoids are associated with a higher risk of morbidity and mortality from chronic diseases. The aim of this study was to examine the effects of a low dose carotenoid mixture (3-mg/1500kcal) for 3 months on serum carotenoid levels and oxidative stress in patients receiving long-term enteral nutrition as the sole source of nutrition. METHODS: This randomized, double blind, controlled study compared patients receiving enteral nutrition with carotenoids (N=26) and without carotenoids (control group; N=25). RESULTS: Patients on long-term enteral nutrition had low baseline serum carotenoid levels. Three months of enteral feeding enriched with carotenoids significantly (P<0.01) increased serum carotenoid levels compared with the control group. Oxidative stress as measured by NF-kappaB levels was decreased at 3 months compared with the control group (P<0.05). No significant changes in MDA levels were observed during the study period in either group. CONCLUSIONS: This study demonstrated that enteral nutrition containing small amounts of carotenoids (3-mg/1500kcal) in patients requiring long-term enteral feeding normalizes serum carotenoid levels to the lower end of the range found in age-matched controls. The NF-kappaB data indicate a reduction in oxidative stress in these patients. Therefore, the use of formulas containing a mixture of carotenoids should be recommended for long-term enteral nutrition.

The effect of fish oil supplementation on cytokine production in children.

The ex vivo production of inflammatory cytokines during fish oil supplementation (n-3 polyunsaturated fatty acids, n-3 PUFA) is a matter of considerable controversy. Studies on human subjects have generally reported decreased lymphocyte proliferation and decreased production of IL-2, interferon-gamma, IL-1beta, IL-6 and TNF-alpha, but other studies showed no effect or even increased production. There are no published reports on ex vivo cytokine production in children on long-term, n-3 PUFA supplementation. The current double-blind study explored cytokine production by peripheral blood mononuclear cells (PBMCs), with and without lipopolysaccharide (LPS) stimulation in children on 12 weeks' supplementation with 300 mg/day of n-3 PUFA. Twenty-one children (aged 8-12 years) were randomized to receive 1 g canola oil (control) or 300 mg n-3 PUFA + 700 mg canola oil in a chocolate spread. Blood was then drawn and PBMCs were separated and cultured for 24 h in a culture medium with or without 10 microg/mL LPS for 5 x 10(6) PBMCs. The pro-inflammatory cytokines, IL-1beta, TNF-alpha and IL-6, and the anti-inflammatory cytokines, IL-10 and IL-1RA, were evaluated by ELISA. The levels of all the cytokines were higher in non-stimulated and LPS-stimulated cultures, from n-3 PUFA-treated subjects as compared to controls. There was no difference in the IL-1beta/IL-1RA ratio between the two groups, with and without LPS stimulation. Nevertheless, the ratio tended to be lower in the treated subjects on both occasions. In conclusion, our results indicate an increased production of both pro-inflammatory and anti-inflammatory cytokines, with and without LPS stimulation, in children on 12 weeks' n-3 PUFA supplementation.