Preoperative oral supplementation with long-chain Omega-3 fatty acids beneficially alters phospholipid fatty acid patterns in liver, gut mucosa, and tumor tissue

Preoperative nutrition therapy in people undergoing gastrointestinal surgery

BACKGROUND

Poor preoperative nutritional status has been consistently linked to an increase in postoperative complications and worse surgical outcomes. We updated a review first published in 2012.

OBJECTIVES

To assess the effects of preoperative nutritional therapy compared to usual care in people undergoing gastrointestinal surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, three other databases and two trial registries on 28 March 2023. We searched reference lists of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of people undergoing gastrointestinal surgery and receiving preoperative nutritional therapy, including parenteral nutrition, enteral nutrition or oral nutrition supplements, compared to usual care. We only included nutritional therapy that contained macronutrients (protein, carbohydrate and fat) and micronutrients, and excluded studies that evaluated single nutrients. We included studies regardless of the nutritional status of participants, that is, well-nourished participants, participants at risk of malnutrition, or mixed populations. We excluded studies in people undergoing pancreatic and liver surgery. Our primary outcomes were non-infectious complications, infectious complications and length of hospital stay. Our secondary outcomes were nutritional aspects, quality of life, change in macronutrient intake, biochemical parameters, 30-day perioperative mortality and adverse effects.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. We assessed risk of bias using the RoB 1 tool and applied the GRADE criteria to assess the certainty of evidence.

MAIN RESULTS

We included 16 RCTs reporting 19 comparisons (2164 participants). Seven studies were new for this update. Participants' ages ranged from 21 to 79 years, and 62% were men. Three RCTs used parenteral nutrition, two used enteral nutrition, eight used immune-enhancing nutrition and six used standard oral nutrition supplements. All studies included mixed groups of well-nourished and malnourished participants; they used different methods to identify malnutrition and reported this in different ways. Not all the included studies were conducted within an Enhanced Recovery After Surgery (ERAS) programme, which is now current clinical practice in most hospitals undertaking GI surgery. We were concerned about risk of bias in all the studies and 14 studies were at high risk of bias due to lack of blinding. We are uncertain if parenteral nutrition has any effect on the number of participants who had a non-infectious complication (risk ratio (RR) 0.61, 95% confidence interval (CI) 0.36 to 1.02; 3 RCTs, 260 participants; very low-certainty evidence); infectious complication (RR 0.98, 95% CI 0.53 to 1.80; 3 RCTs, 260 participants; very low-certainty evidence) or length of hospital stay (mean difference (MD) 5.49 days, 95% CI 0.02 to 10.96; 2 RCTs, 135 participants; very low-certainty evidence). None of the enteral nutrition studies reported non-infectious complications as an outcome. The evidence is very uncertain about the effect of enteral nutrition on the number of participants with infectious complications after surgery (RR 0.90, 95% CI 0.59 to 1.38; 2 RCTs, 126 participants; very low-certainty evidence) or length of hospital stay (MD 5.10 days, 95% CI -1.03 to 11.23; 2 RCTs, 126 participants; very low-certainty evidence). Immune-enhancing nutrition compared to controls may result in little to no effect on the number of participants experiencing a non-infectious complication (RR 0.79, 95% CI 0.62 to 1.00; 8 RCTs, 1020 participants; low-certainty evidence), infectious complications (RR 0.74, 95% CI 0.53 to 1.04; 7 RCTs, 925 participants; low-certainty evidence) or length of hospital stay (MD -1.22 days, 95% CI -2.80 to 0.35; 6 RCTs, 688 participants; low-certainty evidence). Standard oral nutrition supplements may result in little to no effect on number of participants with a non-infectious complication (RR 0.90, 95% CI 0.67 to 1.20; 5 RCTs, 473 participants; low-certainty evidence) or the length of hospital stay (MD -0.65 days, 95% CI -2.33 to 1.03; 3 RCTs, 299 participants; low-certainty evidence). The evidence is very uncertain about the effect of oral nutrition supplements on the number of participants with an infectious complication (RR 0.88, 95% CI 0.60 to 1.27; 5 RCTs, 473 participants; very low-certainty evidence). Sensitivity analysis based on malnourished and weight-losing participants found oral nutrition supplements may result in a slight reduction in infections (RR 0.58, 95% CI 0.40 to 0.85; 2 RCTs, 184 participants). Studies reported some secondary outcomes, but not consistently. Complications associated with central venous catheters occurred in RCTs involving parenteral nutrition. Adverse events in the enteral nutrition, immune-enhancing nutrition and standard oral nutrition supplements RCTs included nausea, vomiting, diarrhoea and abdominal pain.

AUTHORS' CONCLUSIONS

We were unable to determine if parenteral nutrition, enteral nutrition, immune-enhancing nutrition or standard oral nutrition supplements have any effect on the clinical outcomes due to very low-certainty evidence. There is some evidence that standard oral nutrition supplements may have no effect on complications. Sensitivity analysis showed standard oral nutrition supplements probably reduced infections in weight-losing or malnourished participants. Further high-quality multicentre research considering the ERAS programme is required and further research in low- and middle-income countries is needed.

Systematic review of preoperative n-3 fatty acids in major gastrointestinal surgery

Objectives

Perioperative nutrition aims to replenish nutritional stores before surgery and reduce postoperative complications. 'Immunonutrition' (including omega-3 fatty acids) may modulate the immune system and attenuate the postoperative inflammatory response. Hitherto, immunonutrition has overwhelmingly been administered in the postoperative period-however, this may be too late to provide benefit.

Design

A systematic literature search using MEDLINE and EMBASE for randomized controlled trials (RCTs).

Setting

Perioperative major gastrointestinal surgery.

Participants

Patients undergoing major gastrointestinal surgery.

Interventions

Omega-3 fatty acid supplementation commenced in the preoperative period, with or without continuation into postoperative period.

Main outcome measures

The effect of preoperative omega-3 fatty acids on inflammatory response and clinical outcomes.

Results

833 studies were identified. After applying inclusion and exclusion criteria, 12 RCTs, involving 1456 randomized patients, were included. Ten articles exclusively enrolled patients with cancer. Seven studies used a combination of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) as the intervention and five studies used EPA alone. Eight out of 12 studies continued preoperative nutritional support into the postoperative period.Of the nine studies reporting mortality, no difference was seen. Duration of hospitalisation ranged from 4.5 to 18 days with intervention and 3.5 to 23.5 days with control. Omega-3 fatty acids had no effect on postoperative C-reactive protein and the effect on cytokines (including tumor necrosis factor-α, interleukin (IL)-6 and IL-10) was inconsistent. Ten of the 12 studies had low risk of bias, with one study having moderate bias from allocation and blinding.

Conclusions

There is insufficient evidence to support routine preoperative omega-3 fatty acid supplementation for major gastrointestinal surgery, even when this is continued after surgery.

PROSPERO registration number

CRD42018108333.

Nutritional Lipids and Mucosal Inflammation

Inflammatory bowel disease (IBD) is characterized by chronic relapsing inflammation in the intestine. Given their role in regulation of inflammation, long-chain n-3 polyunsaturated fatty acids (PUFAs) represent a potential supplementary therapeutic approach to current drug regimens used for IBD. Mechanistically, there is ample evidence for an anti-inflammatory and pro-resolution effect of long-chain n-3 PUFAs after they incorporate into cell membrane phospholipids. They disrupt membrane rafts and when released from the membrane suppress inflammatory signaling by activating PPAR-γ and free fatty acid receptor 4; furthermore, they shift the lipid mediator profile from pro-inflammatory eicosanoids to specialized pro-resolving mediators. The allocation of long-chain n-3 PUFAs also leads to a higher microbiome diversity in the gut, increases short-chain fatty acid-producing bacteria, and improves intestinal barrier function by sealing epithelial tight junctions. In line with these mechanistic studies, most epidemiological studies support a beneficial effect of long-chain n-3 PUFAs intake on reducing the incidence of IBD. However, the results from intervention trials on the prevention of relapse in IBD patients show no or only a marginal effect of long-chain n-3 PUFAs supplementation. In light of the current literature, international recommendations are supported that adequate diet-derived n-3 PUFAs might be beneficial in maintaining remission in IBD patients.

Efficacy of Cereal-based Oral Nutrition Supplement on Nutritional Status, Inflammatory Cytokine Secretion and Quality of Life in Cancer Patients Under Cancer Therapy

A rapid increase in cancer incidence accompanied by aging population requires evidence-based supportive cancer care practices. Cancer therapies often accompany adverse events which induce malnutrition and declined quality of life. We conducted an 8-week non-randomized clinical trial to evaluate efficacy of cereal-based oral nutritional supplement (ONS) intervention on nutritional status, quality of life and inflammatory responses in cancer patients undergoing cancer therapy with 5% < weight loss. The study included 34 pateints (24 in control group, 10 in intervention group) with 15 drop-outs. ONS used in this intervention contained 0.5% arabinoxylan-rich fermented rice bran powder and 5.5% black rice powder as active ingredients in a regular cereal-based formula. Results showed that ONS intervention for 8 weeks did not show significant improvement in blood biomarkers of nutritional status or patient-generated subjective global assessment scores. However, 8-week of intervention showed reduced interleukin (IL)-6 and IL-1β secretion in lipopolysaccharide-stimulated peripheral blood mononuclear cells while IL-12p70 level was increased. For health-related quality of life (HRQoL) indices, emotional functioning and fatigue symptoms were improved after 4 weeks only in the intervention group although no difference was found at week 8. These results suggest that ONS intervention may improve chronic inflammatory status and HRQoL indices (at week 4) in cancer patients receiving treatments.

Nutritional Aspect of Cancer Care in Medical Oncology Patients

PURPOSE

Awareness of advances in the nutritional aspects of cancer care and translation of this information into clinical practice are important for oncology practitioners to effectively couple oncologic and nutritional approaches throughout the cancer journey. The goal of this consensus statement by a panel of medical oncologists was to provide practical and implementable guidance addressing nutritional aspects of cancer care from the perspective of the medical oncologist.

METHODS

A panel of medical oncologists agreed on a series of statements supported by scientific evidence and expert clinical opinion.

FINDINGS

Participating experts emphasized that both poor nutritional intake and metabolic alterations underlie cancer-related malnutrition. The use of liquid and high energy-dense oral nutritional supplements may enable better patient compliance, whereas higher efficacy is more likely with the use of pharmaconutrient-enriched oral nutritional supplements in terms of improved weight, lean body mass, functional status, and quality of life, as well as better tolerance to antineoplastic treatment. A multimodal approach is currently believed to be the best option to counteract the catabolism leading to cancer-related malnutrition; this treatment is scheduled in parallel with anticancer therapies and includes nutritional interventions, multitarget drug therapies, and exercise and rehabilitation programs. Participating experts emphasized the role of the oncologist as a reference professional figure in the coordination of nutritional care for patients with cancer within the context of complex and different clinical scenarios, particularly for permissive-adjunctive nutritional support.

IMPLICATIONS

This review article provides practical guidance addressing major nutritional aspects of cancer care from the medical oncologist's perspective. Thus, this document is expected to assist oncology practitioners in terms of awareness of advances in the nutritional aspects of cancer care and translation of this information into their clinical practice to effectively couple oncologic and nutritional approaches as part of the continuum of care for patients with cancer.

A double-blind randomized controlled trial of the effects of eicosapentaenoic acid supplementation on muscle inflammation and physical function in patients undergoing colorectal cancer resection

BACKGROUND

Resection of colorectal cancer (CRC) initiates inflammation, mediated at least partly by NFĸB (nuclear factor kappa-light-chain-enhancer of activated B-cells), leading to muscle catabolism and reduced physical performance. Eicosapentaenoic acid (EPA) has been shown to modulate NFĸB, but evidence for its benefit around the time of surgery is limited.

OBJECTIVE

To assess the effect of EPA supplementation on muscle inflammation and physical function around the time of major surgery.

DESIGN

In a double-blind randomized control trial, 61 patients (age: 68.3 ± 0.95 y; 42 male) scheduled for CRC resection, received 3 g per day of EPA (n = 32) or placebo (n = 29) for 5-days before and 21-days after operation. Lean muscle mass (LMM) (via dual energy X-ray absorptiometry (DXA)), anaerobic threshold (AT) (via cardiopulmonary exercise testing (CPET)) and hand-grip strength (HG) were assessed before and 4-weeks after surgery, with muscle biopsies (m. vastus lateralis) obtained for the assessment of NF-ĸB protein expression.

RESULTS

There were no differences in muscle NFĸB between EPA and placebo groups (mean difference (MD) -0.002; 95% confidence interval (CI) -0.19 to 0.19); p = 0.98). There was no difference in LMM (MD 704.77 g; 95% CI -1045.6 g-2455.13 g; p = 0.42) or AT (MD 1.11 mls/kg/min; 95% CI -0.52 mls/kg/min to 2.74 mls/kg/min; p = 0.18) between the groups. Similarly, there was no difference between the groups in HG at follow up (MD 0.1; 95% CI -1.88 to 2.08; p = 0.81). Results were similar when missing data was imputed.

CONCLUSION

EPA supplementation confers no benefit in terms of inflammatory status, as judged by NFĸB, or preservation of LMM, aerobic capacity or physical function following major colorectal surgery.

CLINICAL TRIALS REFERENCE

NCT01320319.

l-Carnitine Improves Postoperative Liver Function in Hepatectomized Patients

BACKGROUND AND AIMS

The effect of perioperative treatment with l-carnitine in hepatectomized patients is unclear. The objective of the current study is to evaluate the short-term outcomes after liver cancer surgery in patients treated with l-carnitine compared with nontreated patients.

METHODS

Patients with primary liver malignancies scheduled to undergo a hepatectomy were randomly assigned to receive either perioperative treatment with l-carnitine (carnitine group) or usual intake (control group). The primary endpoint of this study was the short-term outcome after liver surgery.

RESULTS

The study participants were randomly assigned into 2 groups: 106 patients in the control group and 102 patients in the perioperative l-carnitine supplementation group. The restoration of serum ammonia levels, prothrombin time, and peripheral neutrophil count at 3 days after the operation was significantly faster in the carnitine group than in the control group. Fewer patients in the carnitine group developed grade B posthepatic liver failure, according to the grading system of the International Study Group of Liver Surgery, than patients in the control group (20% vs 76%). The length of hospitalization was significantly shorter in patients in the carnitine group than in those in the control group.

CONCLUSIONS

We found that perioperative treatment with l-carnitine was significantly better than ordinary treatment in reducing postoperative serum ammonia levels, suggesting that l-carnitine may serve as a pivotal regulator of liver injury and repair and result in shorter postoperative hospitalization (ClinicalTrials.gov trial registration no. NCT03021876).

Intravenous omega-3 fatty acids are associated with better clinical outcome and less inflammation in patients with predicted severe acute pancreatitis: A randomised double blind controlled trial

BACKGROUND AND AIMS

Omega-3 fatty acids (FA) can ameliorate the hyper-inflammatory response that occurs in conditions such as severe acute pancreatitis (SAP) and this may improve clinical outcome. We tested the hypothesis that parenteral omega-3 FA from a lipid emulsion that includes fish oil could be beneficial in patients with predicted SAP by reducing C-reactive protein (CRP) concentration (primary outcome), and modulating the inflammatory response and improving clinical outcome (secondary outcomes).

METHODS

In a phase II randomized double-blind single-centre controlled trial, patients with predicted SAP were randomised to receive a daily infusion of fish oil containing lipid emulsion (Lipidem® 20%, BBraun) for 7 days (n = 23) or a daily infusion of a lipid emulsion without fish oil (Lipofundin® MCT 20%, BBraun) (n = 22).

RESULTS

On admission, both groups had comparable pancreatitis predicted severity and APACHE II scores. Administration of fish oil resulted in lower total blood leukocyte number (P = 0.04), CRP (P = 0.013), interleukin-8 (P = 0.05) and intercellular adhesion molecule 1 (P = 0.01) concentrations, multiple organ dysfunction score, sequential organ failure assessment score (P = 0.004), early warning score (P = 0.01), and systemic inflammatory response syndrome (P = 0.03) compared to the control group. The fish oil group had fewer new organ failures (P = 0.07), lower critical care admission rate (P = 0.06), shorter critical care stay (P = 0.03) and shorter total hospital stay (P = 0.04).

CONCLUSIONS

It is concluded that intravenous administration of a fish oil containing lipid emulsion, a source of omega-3 FA, improves clinical outcomes in patients with predicted SAP, benefits that may be linked to reduced inflammation. CLINICALTRIALS.

GOV NUMBER

NCT01745861.

EU CLINICAL TRIALS REGISTER

EudraCT (2010-018660-16).

Protective Effects of Enteral Nutrition Supplemented with Crassostrea hongkongensis Polysaccharides Against 5-Fluorouracil-Induced Intestinal Mucosal Damage in Rats

Chemotherapeutics, including 5-fluorouracil (5-FU), often damage the intestinal mucosal barrier and cause intestinal mucositis (IM). Supplementation with immunoregulatory polysaccharides from Crassostrea hongkongensis has been shown to positively influence the effectiveness and toxicity of 5-FU. Therefore, we studied the effects of oyster polysaccharides on 5-FU-induced intestinal mucosal damage in rats. The C_30-60% ethanol-precipitated fraction of polysaccharides promoted IEC-6 cell proliferation and exhibited a maximal effect at a 0.0195 mg/mL concentration. Moreover, treatment with C_30-60% polysaccharide-based nutrition formula (OPNF) partially prevented the 5-FU-induced degenerative changes in the histology and ultrastructure of small intestinal mucosa. In addition, the endotoxin level of rats fed with 5-FU and OPNF decreased to the normal control level. Furthermore, the 5-FU-induced increase of proinflammatory cytokine interleukin (IL)-2 and the decrease of anti-inflammatory cytokine IL-10 level in the peripheral blood were significantly attenuated by OPNF administration. In conclusion, Oyster C_30-60% polysaccharides can ameliorate 5-FU-induced IM by partially preventing mucosal damage, reducing inflammation, and promoting immunity.

ω3 Polyunsaturated Fatty Acids as Immunomodulators in Colorectal Cancer: New Potential Role in Adjuvant Therapies

Diet composition may affect the onset and progression of chronic degenerative diseases, including cancer, whose pathogenesis relies on inflammatory processes. Growing evidence indicates that diet and its components critically contribute to human health, affecting the immune system, secretion of adipokines, and metabolic pathways. Colorectal cancer (CRC) is one of the leading causes of death worldwide. Antineoplastic drugs are widely used for CRC treatment, but drug resistance and/or off-target toxicity limit their efficacy. Dietary ω3 polyunsaturated fatty acids (PUFA) have been gaining great interest in recent years as possible anti-inflammatory and anticancer agents, especially in areas such as the large bowel, where the pro-inflammatory context promotes virtually all steps of colon carcinogenesis. Growing epidemiological, experimental, and clinical evidence suggests that ω3 PUFA may play a role in several stages of CRC management exhibiting antineoplastic activity against human CRC cells, improving the efficacy of radiation and chemotherapy, ameliorating cancer-associated secondary complications, and preventing CRC recurrence. These effects are most likely related to the immunomodulatory activities of ω3 PUFA that are able to influence several aspects of the inflammatory process ranging from inflammasome activation, leukocyte recruitment, production of immune mediators to differentiation, and activation of immune cells. In this review, we will focus on the potential use of ω3 PUFA as adjuvant agents together with chemo/radiotherapy, highlighting the immunomodulatory effects most likely responsible for their beneficial effects in different stages of CRC management.

Effects of perioperative supplementation with omega-3 fatty acids on leukotriene B₄ and leukotriene B₅ production by stimulated neutrophils in patients with colorectal cancer: a randomized, placebo-controlled intervention trial

Omega-3 fatty acids (n-3 FA) may have beneficial clinical and immune-modulating effects in surgical patients. In a randomized, double-blind, prospective, placebo-controlled trial, 148 patients referred for elective colorectal cancer surgery received an n-3 FA-enriched oral nutritional supplement (ONS) providing 2.0 g of eicosapentaenoic acid (EPA) and 1.0 g of docosahexaenoic acid (DHA) per day or a standard ONS for seven days before surgery. On the day of operation, there was a significant increase in the production of leukotriene B₅ (LTB₅) (p < 0.01) and 5-hydroxyeicosapentaenoic acid (5-HEPE) (p < 0.01), a significant decrease in the production of leukotriene B₄ (LTB₄) (p < 0.01) and a trend for a decrease in the production of 5-hydroxyeicosatetraenoic acid (5-HETE) (p < 0.1) from stimulated neutrophils in the active group compared with controls. There was no association between LTB₄ values and postoperative complications. In conclusion, oral n-3 FA exerts anti-inflammatory effects in surgical patients, without reducing the risk of postoperative complications.

Nutrition optimization prior to surgery

Optimization of metabolic state prior to major surgery leads to improved surgical outcomes. Nutrition screening protocols should be implemented in the preoperative evaluation, possibly as part of a bundle. Strategies to minimize hyperglycemia and insulin resistance by aggressive preoperative nutrition and carbohydrate loading may promote maintenance of a perioperative anabolic state, improving healing, reducing complications, and shortening the time to recovery of bowel function and hospital discharge. Short courses of preoperative immune-modulating formulas, using combinations of arginine, ω-3 fatty acids, and other nutrients, have been associated with improved surgical outcomes. These immune-modulating nutrients are key elements of metabolic pathways that promote attenuation of the metabolic response to stress and improve both wound healing and immune function. Patients with severe malnutrition and gastrointestinal dysfunction may benefit from preoperative parenteral nutrition. Continuation of feeding through the intraoperative period for severely stressed hypermetabolic patients undergoing nongastrointestinal surgery is another strategy to optimize metabolic state and reduce prolonged nutrition deficits. In this paper, we review the importance of preoperative nutrition and strategies for effective preoperative nutrition optimization.

Randomized clinical trial of perioperative omega-3 fatty acid supplements in elective colorectal cancer surgery

BACKGROUND

Omega-3 fatty acids (n-3 FAs) may have beneficial clinical effects, and n-3 FA supplements may improve outcome after surgery.

METHODS

In a randomized double-blind placebo-controlled trial in single centre, patients referred for elective colorectal cancer surgery received either an n-3 FA-enriched oral nutritional supplement (ONS) (Supportan, 200 ml twice daily) providing 2.0 g eicosapentaenoic acid (EPA) and 1.0 g docosahexaenoic acid (DHA) per day, or a standard isocaloric and isonitrogenous ONS, for 7 days before and 7 days after surgery. The primary endpoint was infectious and non-infectious complications within 30 days of surgery. Secondary endpoints were length of hospital stay, intensive care unit admission, readmissions, and concentrations of marine n-3 FAs and arachidonic acid in granulocyte membranes.

RESULTS

Some 148 consecutive patients (68 women, 80 men; mean age 71 (range 41-89) years) were randomized. There was no significant difference between groups in infectious or non-infectious postoperative complications (P = 1.000). Granulocyte levels of EPA, DHA and docosapentaenoic acid (DPA) were significantly higher in the n-3 FA-enriched supplement group compared with the control group (P < 0.001). The arachidonic acid level in granulocytes was significantly lower in the enriched group than in the control group (P < 0.001).

CONCLUSION

EPA, DHA and DPA were incorporated into granulocytes in patients receiving n-3 FAs, but this was not associated with improved postoperative outcomes.

REGISTRATION NUMBER

NCT00488904 (http://www.clinicaltrials.gov).

Rapid incorporation of ω-3 fatty acids into colonic tissue after oral supplementation in patients with colorectal cancer: a randomized, placebo-controlled intervention trial

BACKGROUND

The purpose of the study was to examine whether a preoperative supplement with ω-3 fatty acids (FAs) leads to their incorporation into colonic tissue in patients scheduled for colorectal cancer surgery. This would be of interest because ω-3 FAs have potential beneficial (local) immunological effects that might benefit these patients.

METHODS

In a randomized, double-blind, prospective, placebo-controlled, single-center intervention trial, patients referred for elective colorectal cancer surgery received either an ω-3 FA-enriched oral nutrition supplement (ONS) (200 mL twice daily) providing 2.0 g of eicosapentaenoic acid (EPA) and 1.0 g of docosahexaenoic acid (DHA) per day or a standard ONS for 7 days before surgery. Tissue samples from healthy colonic tissue (mucosa and muscular layer) were obtained during surgery, and tissue fatty acid composition was analyzed by gas chromatography.

RESULTS

EPA was significantly higher in colonic mucosa (P = .001) and in the colonic muscular layer (P = .004) in the ω-3 FA group compared with controls. Patients in the ω-3 FA group also tended to have higher docosapentaenoic acid and DHA levels in colonic tissue.

CONCLUSIONS

EPA is incorporated rapidly into colonic mucosa and colonic muscular layer in patients given 3 g of ω-3 FA daily for 7 days before surgery for colorectal cancer. This may lead to potential beneficially effects on (local) immune function, which might benefit these patients.

Pre-operative nutrition support in patients undergoing gastrointestinal surgery

BACKGROUND

Post-operative management in gastrointestinal (GI) surgery is becoming well established with 'Enhanced Recovery After Surgery' protocols starting 24 hours prior to surgery with carbohydrate loading and early oral or enteral feeding given to patients the first day following surgery. However, whether or not nutritional intervention should be initiated earlier in the preoperative period remains unclear. Poor pre-operative nutritional status has been linked consistently to an increase in post-operative complications and poorer surgical outcome.

OBJECTIVES

To review the literature on preoperative nutritional support in patients undergoing gastrointestinal surgery (GI).

SEARCH METHODS

The searches were initially run in March 2011 and subsequently updated in February 2012. Databases including all EBM Reviews (Cochrane DSR, ACP Journal Club, DARE, CCTR, CMR, HTA and NHSEED) MEDLINE, EMBASE, AMED, British Nursing Index Archive using OvidSP were included and a search was run on each database separately after which duplicates were excluded.

SELECTION CRITERIA

The inclusion criteria were randomised controlled trials that evaluated pre-operative nutritional support in GI surgical participants using a nutritional formula delivered by a parenteral, enteral or oral route. The primary outcomes included post-operative complications and length of hospital stay.

DATA COLLECTION AND ANALYSIS

Two observers screened the abstracts for inclusion in the review and performed data extraction. Bias was assessed for each of the included studies using the bias assessment tables in the Cochrane Software Review Manager (version 5.1, Cochrane Collaboration). The trials were analysed using risk ratios with Mantel-Haenszel in fixed effects methods displayed with heterogeneity. Meta-analyses were undertaken on trials evaluating immune enhancing (IE) nutrition, standard oral supplements, enteral and parenteral nutrition (PN) which were administered pre-operatively.Study characteristics were summarised in tables. Dichotomous and ratio data were entered into meta-analyses for the primary outcomes. These were then summarised in tables with assumed and corresponding risk with relative effect giving 95% confidence intervals.

MAIN RESULTS

The searches identified 9900 titles and, after excluding duplicates, 6433 titles were initially screened. After the initial title screen, 6266 were excluded. Abstracts were screened for 167 studies and 33 articles were identified as meeting the inclusion criteria, of which 13 were included in the review after an assessment of the complete manuscripts.Seven trials evaluating IE nutrition were included in the review, of which 6 were combined in a meta-analysis. These studies showed a low to moderate level of heterogeneity and significantly reduced total post-operative complications (risk ratio (RR) 0.67 CI 0.53 to 0.84). Three trials evaluating PN were included in a meta-analysis and a significant reduction in post-operative complications was demonstrated (RR 0.64 95% CI 0.46 to 0.87) with low heterogeneity, in predominantly malnourished participants. Two trials evaluating enteral nutrition (RR 0.79, 95% CI 0.56 to 1.10) and 3 trials evaluating standard oral supplements (RR 1.01 95% CI 0.56 to 1.10) were included, neither of which showed any difference in the primary outcomes.

AUTHORS' CONCLUSIONS

There have been significant benefits demonstrated with pre-operative administration of IE nutrition in some high quality trials. However, bias was identified which may limit the generalizability of these results to all GI surgical candidates and the data needs to be placed in context with other recent innovations in surgical management (eg-ERAS). Some unwanted effects have also been reported with components of IE nutrition in critical care patients and it is unknown whether there would be detrimental effects by administering IE nutrition to patients who could require critical care support after their surgery. The studies evaluating PN demonstrated that the provision of PN to predominantly malnourished surgical candidates reduced post-operative complications; however, these data may not be applicable to current clinical practice, not least because they have involved a high degree of 'hyperalimentation'. Trials evaluating enteral or oral nutrition were inconclusive and further studies are required to select GI surgical patients for these nutritional interventions.

Omega-3 fatty acid improves the clinical outcome of hepatectomized patients with hepatitis B virus (HBV)-associated hepatocellular carcinoma

Omega-3 fatty acid supplemented total parenteral nutrition improves the clinical outcome of patients undergoing certain operations; however, its benefits for patients with hepatitis type B virus (HBV)-associated hepatocellular carcinoma (HCC) who have undergone hepatectomy are still not clear. The aim of this study was to evaluate the effect of omega-3 fatty acid supplemented total parenteral nutrition on the clinical outcome of patients with HBV-associated HCC who underwent hepatectomy at our institution. A total of 63 patients with HBV-associated HCC who underwent hepatectomy were included in this study. These patients were randomly assigned to receive standard total parenteral nutrition (the control group, n = 31) or omega-3 fatty acid supplemented total parenteral nutrition (the omega-3 fatty acid group, n = 32) for at least 5 d. The study endpoints were the occurrence of infection-related complications, recovery of liver function and length of hospital stay. The results showed that the omega-3 fatty acid group had a lower infection rate (omega-3 fatty acid, 19.4% vs control, 43.8%, P < 0.05), a better liver function after hepatectomy: alanine transaminase (omega-3 fatty acid, 48.23±18.48 U/L vs control, 73.34±40.60 U/L, P < 0.01), aspartate transaminase (omega-3 fatty acid, 35.77±14.56 U/L vs control, 50.53±24.62 U/L, P < 0.01), total bilirubin (omega-3 fatty acid, 24.29±7.40 mmol/L vs control, 28. 37±8.06 mmol/L, P < 0.05) and a shorter length of hospital stay (omega-3 fatty acid, 12.71±2.58 d vs control, 15.91±3.23 d, P < 0.01). The serum contents of IL-6 (omega-3 fatty acid, 23.98±5.63 pg/mL vs control, 35.55±7.5 pg/mL, P < 0.01) and TNF-α (omega-3 fatty acid, 4.43±1.22 pg/mL vs control, 5.96±1.58 pg/mL, P < 0.01) after hepatectomy were significantly lower in the omega-3 fatty acid group than those of the control group. In conclusion, administration of omega-3 fatty acid may reduce infection rate and improve liver function recovery in HBV-associated HCC patients after hepatectomy. This improvement is associated with suppressed production of proinflammatory cytokines in these patients.

Docosahexaenoic fatty acid (DHA) in the regulation of colon cell growth and cell death: a review

BACKGROUND

Experimental, epidemiological and clinical data substantiate the beneficial role of n-3 polyunsaturated fatty acids (PUFAs) in preventing inflammation and cancer of the colon. This review covers the unsaturated docosahexaenoic fatty acid (DHA), describes some of its important cellular and molecular mechanisms, its interaction with another dietary lipid, butyrate and with endogenous apoptotic regulators of the tumour necrosis factor (TNF) family. We also discuss the clinical impact of this knowledge and the use of these lipids in colon cancer prevention and treatment.

RESULTS

From the literature, DHA has been shown to suppress the growth, induce apoptosis in colon cancer cells in vitro and decrease the incidence and growth of experimental tumours in vivo. Based on these data and our own experimental results, we describe and discuss the possible mechanisms of DHA anticancer effects at various levels of cell organization. We show that DHA can sensitize colon cancer cells to other chemotherapeutic/chemopreventive agents and affect the action of physiological apoptotic regulators of the TNF family.

CONCLUSION

Use of n-3 PUFAs could be a relatively non-toxic form of supportive therapy for improving colon cancer treatment and slowing down or preventing its recurrence. However, it is necessary to use them with caution, based on solid scientific evidence of their mechanisms of action from the molecular to the cellular and organism levels.

Immune mediators of postoperative ileus

CLINICAL BACKGROUND: In all patients undergoing abdominal surgery, a transient phase of interruption of bowel motility, named postoperative ileus (POI) occurs. POI is often accepted as an unavoidable "physiological" response and a self-limiting complication after surgery although it has a significant impact on patient morbidity with prolonged hospitalization and increased costs. Annual economic burden has been estimated as much as US $1.47 billion in the USA (Iyer et al. in J Manag Care Pharm 15(6):485-494, 2009).

PATHOPHYSIOLOGY

The pathophysiology has been elucidated within the last decades, demonstrating that both, neurogenic and inflammatory mechanisms are involved in response to the surgical trauma. It is now generally accepted that POI pathogenesis processes in two phases: a first neurogenic phase is accountable for the immediate postoperative impairment of bowel motility. This is followed by a second immunological phase that can last for days and mainly affects strength and length of POI. More recent findings demonstrate a bidirectional interaction between the nervous and the immune system, and this interaction significantly contributed to our present understanding of POI pathophysiology. Although nerval mechanisms have a significant impact in the early phase of POI, the contribution of the immune system and subsequently its manipulation has risen as the most promising strategy in prevention or treatment of the clinically relevant prolonged form of POI.

AIMS

The present manuscript will give an update on the inflammatory responses, the involved cell types, and participating immune mediators in POI.

Determinants of DHA incorporation into tumor tissue during dietary DHA supplementation

Docosahexaenoic acid (DHA), upon incorporation into tumor tissue, has the potential to sensitize tumors to the effects of chemotherapy or radiation therapy. Although DHA has usually been supplied to tumor tissue in the diet, appropriate dietary conditions required to obtain optimal tumor levels have not been established. Hence, we studied mammary tumor tissue responses in rats fed various durations and doses of DHA. Rats fed a palm oil enriched diet (diet 0) were switched to diets providing either 0.8 g DHA/day (diet 1) or 1.5 g DHA/day (diet 2). Tumor tissue fatty acid composition was analysed at baseline (diet 0), at weeks 1, 4 and 9 during diet 1 and at week 4 during diet 2. Dietary DHA supplementation differentially increased DHA within phospholipids (PL) and triacylglycerol (TAG) fractions in tumors. DHA level equilibrated between 2 and 4 weeks in PL while DHA increase was more progressive in TAG and did not reach a steady state. A higher dose of DHA further increased DHA content in tumor PL and TAG (P = 0.018 and P < 0.001, respectively). DHA concentration in plasma PL was positively correlated with DHA in tumor PL (r = 0.72; P = 0.0003) and TAG (r = 0.64; P = 0.003). We conclude that dietary DHA supplementation enhances tumor content of DHA in a time- and dose-dependent manner, and that the DHA level in plasma PL could be used as a proxy for tumor DHA. These findings have implications for dietary DHA supplementations in cancer patients.

Safety and efficacy of fish oil-enriched parenteral nutrition regimen on postoperative patients undergoing major abdominal surgery: a meta-analysis of randomized controlled trials

BACKGROUND

To evaluate the safety and efficacy of a fish oil-enriched parenteral nutrition regimen in patients undergoing major abdominal surgery, a meta-analysis of randomized controlled trials was conducted.

METHODS

An electronic search of PubMed, MEDLINE, EMBASE, Academic Search Premier, and China National Knowledge Infrastructure databases was performed in March 2009. RevMan 5.0 was used for statistical analysis.

RESULTS

The combined analysis showed that a fish oil-enriched parenteral nutrition regimen had a positive treatment effect on length of hospital stay (weighed mean difference = -2.98, P < .001), length of intensive care unit stay, postoperative infection rate (odds ratio = 0.56, P = .04), and serum levels of aspartate aminotransferase, alanine aminotransferase, and alpha-tocopherol on postoperative day 6 in these patients. The regimen increased the plasma levels of eicosapentaenoic acid (standardized mean difference = 3.11, P < .001) and docosahexaenoic acid and upregulated the leukotriene B(5) production in leukocytes on postoperative day 6. No significant differences were found between the 2 groups in postoperative mortality; incidence of postoperative cardiac complications; serum levels of bilirubin, triglyceride, or arachidonic acid; or the liberation of leukotriene B(4). No serious adverse events related to fish oil treatment were reported.

CONCLUSIONS

Based on the meta-analysis, fish oil-supplemented parenteral nutrition was safe, improved clinical outcomes, and altered the fatty acid pattern as well as leukotriene synthesis. More laboratory parameters should be considered in future meta-analyses.

Influence of diet enriched with conjugated linoleic acids on their distribution in tissues of rats with DMBA induced tumors

Backround

Conjugated linoleic acids (CLA) are a group of positional and geometric isomers of linoleic acid with proven beneficial influence on health. They show e.g. anticarcinogenic, antiobesity, and antiatherogenic effect. Milk, dairy products and meat of poligastric animals are their most valuable dietary sources, with cis-9, trans-11 CLA (RA - rumenic acid) being the predominant isomer. Dietary supplements with CLA became very popular, mainly among the overweight and bodybuilders.

The aim of this study was to examine the influence of the food supplements with conjugated linoleic acid on carcinogenesis in female Sprague-Dawley rats and evaluation of CLA and other fatty acids distribution in their bodies.

Animals were divided into four groups depending on the diet supplementation (oil or Bio-C.L.A. (Pharma Nord Denmark) given intragastrically) and presence or absence of carcinogenic agent (7,12-dimethylbenz[a]antharcene). Animals were decapitated at 21st week of experiment and serum and microsomes were extracted.

Results and conclusions

The mammary tumours (adenocarcinoma) occurred in groups treated with DMBA. Diet enriched with CLA decreased the cancer morbidity (67% in Bio-C.L.A. compared to 88% in oil) and delayed the cancer induction (p = 0.0018). There were no differences in body and organs weight.

The supplement used in the study was a mixture of several fatty acids with the greatest proportion of CLA isomers: trans-10, cis-12 (33%) and cis-9, trans-11 (31%). Both of them were present in tissues but the content of rumenic acid was greater. Dietary supplementation had also significant impact on other fatty acids content, both in serum and in microsomes.

Effects of a fish oil containing lipid emulsion on plasma phospholipid fatty acids, inflammatory markers, and clinical outcomes in septic patients: a randomized, controlled clinical trial

INTRODUCTION

The effect of parenteral fish oil in septic patients is not widely studied. This study investigated the effects of parenteral fish oil on plasma phospholipid fatty acids, inflammatory mediators, and clinical outcomes.

METHODS

Twenty-five patients with systemic inflammatory response syndrome or sepsis, and predicted to need parenteral nutrition were randomized to receive either a 50:50 mixture of medium-chain fatty acids and soybean oil or a 50:40:10 mixture of medium-chain fatty acids, soybean oil and fish oil. Parenteral nutrition was administrated continuously for five days from admission. Cytokines and eicosanoids were measured in plasma and in lipopolysaccharide-stimulated whole blood culture supernatants. Fatty acids were measured in plasma phosphatidylcholine.

RESULTS

Fish oil increased eicosapentaenoic acid in plasma phosphatidylcholine (P < 0.001). Plasma interleukin (IL)-6 concentration decreased significantly more, and IL-10 significantly less, in the fish oil group (both P < 0.001). At Day 6 the ratio PO2/FiO2 was significantly higher in the fish oil group (P = 0.047) and there were fewer patients with PO2/FiO2 <200 and <300 in the fish oil group (P = 0.001 and P = 0.015, respectively). Days of ventilation, length of intensive care unit (ICU) stay and mortality were not different between the two groups. The fish oil group tended to have a shorter length of hospital stay (22 +/- 7 vs. 55 +/- 16 days; P = 0.079) which became significant (28 +/- 9 vs. 82 +/- 19 days; P = 0.044) when only surviving patients were included.

CONCLUSIONS

Inclusion of fish oil in parenteral nutrition provided to septic ICU patients increases plasma eicosapentaenoic acid, modifies inflammatory cytokine concentrations and improves gas exchange. These changes are associated with a tendency towards shorter length of hospital stay.

TRIALS REGISTRATION

Clinical Trials Registration Number ISRCTN89432944.

Improving outcome of chemotherapy of metastatic breast cancer by docosahexaenoic acid: a phase II trial

BACKGROUND

Breast cancer becomes lethal when visceral metastases develop. At this stage, anti-cancer treatments aim at relieving symptoms and delaying death without resulting in additional toxicity. On the basis of their differential anti-oxidant defence level, tumour cells can be made more sensitive to chemotherapy than non-tumour cells when membrane lipids are enriched with docosahexaenoic acid (DHA), a peroxidisable and oxidative-stress-inducing lipid of marine origin.

METHODS

This open-label single-arm phase II study evaluated the safety and efficacy (response rate), as primary end points, of the addition of 1.8 g DHA daily to an anthracycline-based chemotherapy (FEC) regimen in breast cancer patients (n = 25) with rapidly progressing visceral metastases. The secondary end points were time to progression (TTP) and overall survival (OS).

RESULTS

The objective response rate was 44%. With a mean follow-up time of 31 months (range 2-96 months), the median TTP was 6 months. Median OS was 22 months and reached 34 months in the sub-population of patients (n = 12) with the highest plasma DHA incorporation. The most common grade 3 or 4 toxicity was neutropaenia (80%).

CONCLUSION

DHA during chemotherapy was devoid of adverse side effects and can improve the outcome of chemotherapy when highly incorporated. DHA has a potential to specifically chemosensitise tumours.

Influence of an eicosapentaenoic and docosahexaenoic acid-enriched enteral nutrition formula on plasma fatty acid composition and biomarkers of insulin resistance in the elderly

BACKGROUND & AIMS

n-3 Polyunsaturated fatty acids may improve cardiovascular outcomes in elderly. The aim of this study was to determine the effect of feeding elderly patients exclusively with an n-3 polyunsaturated fatty acid-enriched diet specifically designed for enteral nutrition for 6 months, evaluating modifications in plasma fatty acid profile and some biomarkers of insulin resistance (IR).

METHODS

Thirty-two patients >65 years were fed a new enteral formula (T-Diet Plus) containing 75 mg/l of eicosapentaenoic acid (EPA) and 35 mg/l of docosahexaenoic acid (DHA) and 33 were fed an enteral diet intended for elderly (Jevity). Blood samples were drawn at the beginning and after 3 and 6 months of feeding. Plasma lipids, total plasma and lipid fraction fatty acid profiles, and some IR-associated adipokines were analysed.

RESULTS

Feeding on T-Diet Plus allowed EPA and DHA incorporation into plasma lipids and normalised blood triacylglycerols (TAG) levels after 3 months without major changes in IR, leptin and adiponectin.

CONCLUSIONS

Feeding the elderly exclusively with an enteral formula enriched with EPA and DHA improves their plasma lipid fatty acid profile and lowers TAG, a well known cardiovascular risk biomarker, without affecting IR.

Enteral nutrition enriched with eicosapentaenoic acid (EPA) preserves lean body mass following esophageal cancer surgery: results of a double-blinded randomized controlled trial

BACKGROUND

Esophagectomy represents an exemplar of controlled major trauma, with marked metabolic, immunologic, and physiologic changes as well as an associated high incidence of complications. Eicosapentaenoic acid (EPA) enriched enteral nutrition (EN) modulates immune function and limits catabolism in patients with advanced cancer, but its impact in the peri-operative period is unclear.

OBJECTIVES

To examine the effects of perioperative EPA enriched EN on the metabolic, nutritional, and immuno-inflammatory response to esophagectomy, and on postoperative complications.

METHODS

In a double-blind design, patients were randomized to a standard EN formula or a formula enriched with 2.2 g EPA/d for 5 days preoperatively (orally) and 21 days postoperatively (jejunostomy). Segmental bioelectrical impedance analysis was performed preoperatively and on POD 21. Postoperative complications were monitored, as well as the acute phase response, coagulation markers, and serum cytokines.

RESULTS

Fifty-three patients (28 EPA, 25 standard) completed the study, and both groups were well matched. Serum and peripheral blood mononuclear cell (PBMC) membrane EPA levels were significantly increased in the EPA group. There was no difference in the incidence of major complications. The EPA group maintained all aspects of body composition postoperatively, whereas patients in the standard EN group lost significant amounts of fat-free mass (1.9 kg, P = 0.030) compared with the EPA group [leg (0.3 kg, P = 0.05), arm (0.17 kg, P = 0.01), and trunk (1.44 kg, P = 0.03)]. The EPA group had a significantly (P < 0.05) attenuated stress response for TNFalpha, IL-10, and IL-8 compared with the standard group.

CONCLUSIONS

EPA supplemented early EN is associated with preservation of lean body mass post esophagectomy compared with a standard EN. These properties may merit longer-term study to address its impact on recovery of function and quality of life in models of complex surgery or multimodal cancer treatment regimens.

Long-chain n-3 fatty acids in lipid rafts: implications for anti-inflammatory effects

Emerging evidence indicates that dietary intake of long-chain n-3 fatty acids changes the lipid composition of lipid rafts and caveolae, which are cholesterol- and sphingolipid-rich microdomains of the plasma membrane. Membrane proteins that are involved in signal transduction events relevant to inflammation are specifically localised to these microdomains. By altering the lipid composition of the membrane microdomains, n-3 fatty acids have the potential to modulate these signalling events and exert anti-inflammatory actions.

Influence of adding fish oil to parenteral nutrition on gut-associated lymphoid tissue

BACKGROUND

Lack of enteral nutrition reduces gut-associated lymphoid tissue (GALT) mass and function, a mechanism underlying the increased morbidity of infectious complications in severely injured or critically ill patients. Strategies to restore parenteral nutrition (PN)-induced changes of GALT mass and function have been pursued. However, the influences of adding fish oil to PN on gut immunity remain to be clarified.

METHODS

Male Institute of Cancer Research (ICR) mice (n = 50) were randomized to 4 groups: ad libitum chow (chow), fat free PN (fat (-)-PN), PN + fish oil (FO-PN), and PN + safflower oil (SO-PN). The PN groups were given isocaloric and isonitrogenous PN solutions. The FO- and SO-PN groups received 20% of total calories from fat emulsions. After 5 days of feeding, lymphocytes from Peyer's patches (PPs), the intraepithelial space (IE), and the lamina propria (LP) of the entire small intestine were isolated. GALT lymphocyte numbers and phenotypes (CD4+, CD8+, alphabetaTCR+, gammadeltaTCR+, B220+ cells) were determined. Immunoglobulin A (IgA) levels of small intestinal washings were also measured by enzyme-linked immunosorbent assay. Another set of mice (n = 24) was used to determine plasma fatty acid compositions after feeding.

RESULTS

Lymphocyte numbers from PPs and the LP and intestinal IgA levels were significantly lower in the PN groups than in the chow group, with no significant differences between any 2 PN groups. The FO- and SO-PN groups showed moderate recovery of IE cell numbers compared with the fat (-)-PN group. Omega-3 and omega-6 fatty acid levels were increased with fish and safflower oil additions, respectively, compared with the fat (-)-PN group.

CONCLUSIONS

Adding fish oil to PN does not exacerbate PN-induced GALT changes but rather partially reverses these changes, with increased plasma omega-3 fatty acid levels.

Effect of an immunonutrient mix on human colorectal adenocarcinoma cell growth and viability

OBJECTIVE

L-Glutamine, L-arginine, RNA, and omega-3 polyunsaturated fatty acids (PUFAs) have been incorporated into nutritional formulas to improve immunity of patients with gastrointestinal cancer. We therefore examined the individual and net effects of these immunonutrients on four different human colorectal adenocarcinoma cell lines.

METHODS

LS174T, HT-29, CO112, and Caco-2 cells were exposed to dilutions of 1:50, 1:100, and 1:1000 of a mix or individual components of a mix of 15 g/L of L-glutamine, 16.3 g/L of L-arginine, 1.6 g/L of RNA, and 2.7 g/L of omega-3 PUFAs. Cell growth kinetic was assessed using cell count with a flow cytometer. Cell cycle and apoptosis were evaluated with double fluorescence-activated cell sorter analyses using bromodeoxyuridine labeling index and annexin V staining, respectively. One-way analysis of variance and Student's t tests were used for comparison.

RESULTS

Evaluation of the cell growth kinetic over an 18-d period showed that the immunonutrient mix stimulated cancer cell growth only when diluted > or =100 times. Individual component evaluation indicated that the cell growth stimulation was mainly due to the presence of L-glutamine and to a lesser extent RNA in the mix. L-Arginine had no effect. At a lower dilution of 1:50, omega-3 PUFA concentrations were sufficient to induce cell cycle arrest and massive cell death in part through apoptosis.

CONCLUSION

These results suggest that cancer cell growth stimulation by current immunonutrient formulas is unlikely due to predominant cytotoxic effect of omega-3 PUFAs.

Omega-3 fatty acid effects on biochemical indices following cancer surgery

Epidemiological studies have indicated that a high intake of saturated fat and/or animal fat increases the risk of colon and breast cancer. Laboratory and clinical investigations have shown a reduced risk of colon carcinogenesis after alimentation with omega-3 fatty acids, as found in fish oil. Mechanisms accounting for these anti-tumor effects are reduced levels of PGE(2) and inducible NO synthase as well as an increased lipid peroxidation, or translation inhibition with subsequent cell cycle arrest. Further, omega-3 eicosapentaenoic acid is capable of down-regulating the production and effect of a number of mediators of cachexia, such as IL-1, IL-6, TNF-alpha and proteolysis-inducing factor. In patients with advanced cancer, it is possible to increase energy and protein intake via an enteral or parenteral route, but this seems to have little impact on progressive weight loss. Fish oil administration improved patients' conditions in cancer cachexia and during radio- and chemotherapy. In patients undergoing tumor resection surgery we observed improvement of liver and pancreas biochemical indices when omega-3 fatty acids were administered. This paper is a review of recent developments in the field of nutrition in cancer patients with emphasis on the acute phase response following cancer surgery and the beneficial aspects of fish oil administration.

Effect of cobalt ions on lipid and sterol metabolism in the marine invertebrates Mytilus galloprovincialis and Actinia equina

The lipid and sterol fractions of the mussel Mytilus galloprovincialis and the anemone Actinia equina were analyzed before and after incubation with cobalt ions. There were significant changes in the lipid and sterol composition, strongly depending on the cobalt ions concentrations. The changes in the lipid composition of both invertebrates were different for neutral lipids and phospholipids. These changes concern the length of the fatty acid chains as well as their unsaturation. The cobalt ions inhibited the oxidation of sterols and their alkylation at C-24. Because of these results we can assume that some of the changes caused by cobalt ions might possess adaptive value.

Effects of postoperative enteral immune-enhancing nutrients on plasma endotoxin level, plasma endotoxin inactivation capacity and clinical prognosis

AIM: To investigate the effects of immune-enhancing nutrients such as glutamine, arginine and w-3-fatty acid on the plasma endotoxin, plasma sCD14, plasma endotoxin inactivation capacity and clinical prognosis of patients received gastrointestinal operations.

METHODS: Forty patients received gastrointestinal operations were randomly divided into two groups (20 for each). One group received standard enteral nutrition and the other was fed the standard formulation supplemented with glutamine, arginine and ω-3-fatty acid. One day after the operation, the patients were administered with the above nutrients that contained equal energy and equal amount of nitrogen for 7 d. Blood samples were collected 1 day before the operation and 1, 4 and 7 d after the operation for the detection of plasma endotoxin level and endotoxin inactivation capacity (EIC). The infection-associated complications and the prognosis were also evaluated.

RESULTS: There were no significant differences between the two groups in plasma endotoxin levels and the infection-associated complications. After the operation, a rapid reduction in plasma endotoxin inactivation capacity was observed in both groups, but a significant restoration the plasma endotoxin inactivation capacity was observed 4 d after the operation in the study group (0.12±0.02 kEU/L and 0.078±0.022 kEU/L for the control and study group, respectively, P<0.01). Shortened hospital stay was observed in the study group (11.7±2.0 and 10.6±1.2 d in the control study group, respectively, P<0.05).

CONCLUSION: Perioperative parenteral nutrition supplemented with immune-enhancing nutrients can ameliorate the postoperative immunodepression, but it has no significant effect on endotoxemia.