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

Understanding the Role of Polyunsaturated Fatty Acids in the Development and Prevention of Cancer

Polyunsaturated fatty acids (PUFAs), notably omega-3 (n-3) and omega-6 (n-6), have received much attention owing to their multifaceted effects not only in the management of diverse pathological conditions but also in the maintenance of overall health of an individual. A disproportionately high n-6 to n-3 ratio contributes to the development of various disorders including cancer, which ranks as a leading cause of death worldwide with profound social and economic burden. Epidemiological studies and clinical trials combined with the animal and cell culture models have demonstrated the beneficial effects of n-3 PUFAs in reducing the risk of various cancer types including breast, prostate and colon cancer. The anti-cancer actions of n-3 PUFAs are mainly attributed to their role in the modulation of a wide array of cellular processes including membrane dynamics, apoptosis, inflammation, angiogenesis, oxidative stress, gene expression and signal transduction pathways. On the contrary, n-6 PUFAs have been shown to exert pro-tumor actions; however, the inconsistent findings and controversial data emphasize upon the need to further investigation. Nevertheless, one of the biggest challenges in future is to optimize the n-6 to n-3 ratio despite the genetic predisposition, age, gender and disease severity. Moreover, a better understanding of the potential risks and benefits as well as the cellular and molecular mechanisms of the basic actions of these PUFAs is required to explore their role as adjuvants in cancer therapy. All these aspects will be reviewed in this chapter.

Anti-Inflammatory and Immune Properties of Polyunsaturated Fatty Acids (PUFAs) and Their Impact on Colorectal Cancer (CRC) Prevention and Treatment

Colorectal cancer (CRC) remains a leading cause of death from cancer worldwide, with increasing incidence in the Western world. Diet has become the focus of research as a significant risk factor for CRC occurrence, and the role of dietary polyunsaturated fatty acids (PUFAs) has become an area of interest given their potential role in modulating inflammation, particularly in the pro-carcinogenic inflammatory environment of the colon. This work reviews the main types of PUFAs, their characteristics, structure, and physiologic role. We then highlight their potential role in preventing CRC, their signaling function vis-à-vis tumorigenic signaling, and their subsequent potential role in modulating response to different treatment modalities. We review pre-clinical and clinical data and discuss their potential use as adjunct therapies to currently existing treatment modalities. Given our understanding of PUFAs' immune and inflammation modulatory effects, we explore the possible combination of PUFAs with immune checkpoint inhibitors and other targeted therapies.

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.

Omega-3 polyunsaturated fatty acids: moving towards precision use for prevention and treatment of colorectal cancer

Data from experimental studies have demonstrated that marine omega-3 polyunsaturated fatty acids (O3FAs) have anti-inflammatory and anticancer properties. In the last decade, large-scale randomised controlled trials of pharmacological delivery of O3FAs and prospective cohort studies of dietary O3FA intake have continued to investigate the relationship between O3FA intake and colorectal cancer (CRC) risk and mortality. Clinical data suggest that O3FAs have differential anti-CRC activity depending on several host factors (including pretreatment blood O3FA level, ethnicity and systemic inflammatory response) and tumour characteristics (including location in the colorectum, histological phenotype (eg, conventional adenoma or serrated polyp) and molecular features (eg, microsatellite instability, cyclooxygenase expression)). Recent data also highlight the need for further investigation of the effect of O3FAs on the gut microbiota as a possible anti-CRC mechanism, when used either alone or in combination with other anti-CRC therapies. Overall, these data point towards a precision approach to using O3FAs for optimal prevention and treatment of CRC based on mechanistic understanding of host, tumour and gut microbiota factors that predict anticancer activity of O3FAs.

Long-term outcomes after perioperative treatment with omega-3 fatty acid supplements in colorectal cancer

Background

This study aimed to evaluate the effect of perioperative supplementation with omega‐3 fatty acids (n‐3 FA) on perioperative outcomes and survival in patients undergoing colorectal cancer surgery.

Methods

Patients scheduled for elective resection of colorectal cancer between 2007 and 2010 were randomized to either an n‐3 FA‐enriched oral nutrition supplement (ONS) twice daily or a standard ONS (control) for 7 days before and after surgery. Outcome measures, including postoperative complications, 3‐year cumulative incidence of local or metastatic colorectal cancer recurrence and 5‐year overall survival, were compared between the groups.

Results

Of 148 patients enrolled in the study, 125 (65 patients receiving n‐3 FA‐enriched ONS and 60 receiving standard ONS) were analysed. There were no differences in postoperative complications after surgery (P = 0·544). The risk of disease recurrence at 3 years was similar (relative risk 1·66, 95 per cent c.i. 0·65 to 4·26).The 5‐year survival rate of patients treated with n‐3 FA was 69·2 (95 per cent c.i. 56·5 to 78·9) per cent, compared with 81·7 (69·3 to 89·4) per cent in the control group (P = 0·193). After adjustment for age, stage of disease and adjuvant chemotherapy, n‐3 FA was associated with higher mortality compared with controls (hazard ratio 1·73, 95 per cent c.i. 1·06 to 2·83; P = 0·029). The interaction between n‐3 FA and adjuvant chemotherapy was not statistically significant.

Conclusion

Perioperative supplementation with n‐3 FA did not confer a survival benefit in patients undergoing colorectal cancer surgery. n‐3 FA did not benefit the subgroup of patients treated with adjuvant chemotherapy or decrease the risk of disease recurrence.

Omega-3 Polyunsaturated Fatty Acids and Their Health Benefits

Omega-3 polyunsaturated fatty acids (PUFAs) include α-linolenic acid (ALA; 18:3 ω-3), stearidonic acid (SDA; 18:4 ω-3), eicosapentaenoic acid (EPA; 20:5 ω-3), docosapentaenoic acid (DPA; 22:5 ω-3), and docosahexaenoic acid (DHA; 22:6 ω-3). In the past few decades, many epidemiological studies have been conducted on the myriad health benefits of omega-3 PUFAs. In this review, we summarized the structural features, properties, dietary sources, metabolism, and bioavailability of omega-3 PUFAs and their effects on cardiovascular disease, diabetes, cancer, Alzheimer's disease, dementia, depression, visual and neurological development, and maternal and child health. Even though many health benefits of omega-3 PUFAs have been reported in the literature, there are also some controversies about their efficacy and certain benefits to human health.

The Impact of Preoperative Immune Modulating Nutrition on Outcomes in Patients Undergoing Surgery for Gastrointestinal Cancer: A Systematic Review and Meta-analysis

OBJECTIVE

To define the influence of preoperative immune modulating nutrition (IMN) on postoperative outcomes in patients undergoing surgery for gastrointestinal cancer.

BACKGROUND

Although studies have shown that perioperative IMN may reduce postoperative infectious complications, many of these have included patients with benign and malignant disease, and the optimal timing of such an intervention is not clear.

METHODS

The Embase, Medline, and Cochrane databases were searched from 2000 to 2018, for prospective randomized controlled trials evaluating preoperative oral or enteral IMN in patients undergoing surgery for gastrointestinal cancer. The primary endpoint was the development of postoperative infectious complications. Secondary endpoints included postoperative noninfectious complications, length of stay, and up to 30-day mortality. The analysis was performed using RevMan v5.3 software.

RESULTS

Sixteen studies reporting on 1387 patients (715 IMN group, 672 control group) were included. Six of the included studies reported on a mixed population of patients undergoing all gastrointestinal cancer surgery. Of the remaining, 4 investigated IMN in colorectal cancer surgery, 2 in pancreatic surgery, and another 2 in patients undergoing surgery for gastric cancer. There was 1 study each on liver and esophageal cancer. The formulation of nutrition used in all studies in the treated patients was Impact (Novartis/Nestlé), which contains ω-3 fatty acids, arginine, and nucleotides. Preoperative IMN in patients undergoing surgery for gastrointestinal cancer reduced infectious complications [odds ratio (OR) 0.52, 95% confidence interval (CI) 0.38-0.71, P < 0.0001, I = 16%, n = 1387] and length of hospital stay (weighted mean difference -1.57 days, 95% CI -2.48 to -0.66, P = 0.0007, I = 34%, n = 995) when compared with control (isocaloric isonitrogeneous feed or normal diet). It, however, did not affect noninfectious complications (OR 0.98, 95% CI 0.73-1.33, P = 0.91, I = 0%, n = 1303) or mortality (OR 0.55, 95% CI 0.18-1.68, P = 0.29, I = 0%, n = 955).

CONCLUSION

Given the significant impact on infectious complications and a tendency to shorten length of stay, preoperative IMN should be encouraged in routine practice in patients undergoing surgery for gastrointestinal cancer.

Omega-3 fatty acids, membrane remodeling and cancer prevention

Proteins are often credited as the macromolecule responsible for performing critical cellular functions, however lipids have recently garnered more attention as our understanding of their role in cell function and human health becomes more apparent. Although cellular membranes are the lipid environment in which many proteins function, it is now apparent that protein and lipid assemblies can be organized to form distinct micro- or nanodomains that facilitate signaling events. Indeed, it is now appreciated that cellular function is partly regulated by the specific spatiotemporal lipid composition of the membrane, down to the nanosecond and nanometer scale. Furthermore, membrane composition is altered during human disease processes such as cancer and obesity. For example, an increased rate of lipid/cholesterol synthesis in cancerous tissues has long been recognized as an important aspect of the rewired metabolism of transformed cells. However, the contribution of lipids/cholesterol to cellular function in disease models is not yet fully understood. Furthermore, an important consideration in regard to human health is that diet is a major modulator of cell membrane composition. This can occur directly through incorporation of membrane substrates, such as fatty acids, e.g., n-3 polyunsaturated fatty acids (n-3 PUFA) and cholesterol. In this review, we describe scenarios in which changes in membrane composition impact human health. Particular focus is placed on the importance of intrinsic lipid/cholesterol biosynthesis and metabolism and extrinsic dietary modification in cancer and its effect on plasma membrane properties.

Butyrate and docosahexaenoic acid interact in alterations of specific lipid classes in differentiating colon cancer cells

Docosahexaenoic acid (DHA) and sodium butyrate (NaBt) exhibit a number of interactive effects on colon cancer cell growth, differentiation, or apoptosis; however, the molecular mechanisms responsible for these interactions and their impact on cellular lipidome are still not fully clear. Here, we show that both dietary agents together induce dynamic alterations of lipid metabolism, specific cellular lipid classes, and fatty acid composition. In HT-29 cell line, a model of differentiating colon carcinoma cells, NaBt supported incorporation of free DHA into non-polar lipids and their accumulation in cytoplasmic lipid droplets. DHA itself was not incorporated into sphingolipids; however, it significantly altered representation of individual ceramide (Cer) classes, in particular in combination with NaBt (DHA/NaBt). We observed altered expression of enzymes involved in Cer metabolism in cells treated with NaBt or DHA/NaBt, and exogenous Cer 16:0 was found to promote induction of apoptosis in differentiating HT-29 cells. NaBt, together with DHA, increased n-3 fatty acid synthesis and attenuated metabolism of monounsaturated fatty acids. Finally, DHA and/or NaBt altered expression of proteins involved in synthesis of fatty acids, including elongase 5, stearoyl CoA desaturase 1, or fatty acid synthase, with NaBt increasing expression of caveolin-1 and CD36 transporter, which may further promote DHA incorporation and its impact on cellular lipidome. In conclusion, our results indicate that interactions of DHA and NaBt exert complex changes in cellular lipidome, which may contribute to the alterations of colon cancer cell differentiation/apoptotic responses. The present data extend our knowledge about the nature of interactive effects of dietary fatty acids.

Very long-chain n-3 fatty acids and human health: fact, fiction and the future

EPA and DHA appear to be the most important n-3 fatty acids, but roles for n-3 docosapentaenoic acid are now also emerging. Intakes of EPA and DHA are usually low, typically below those recommended. Increased intakes result in higher concentrations of EPA and DHA in blood lipids, cells and tissues. Increased content of EPA and DHA modifies the structure of cell membranes and the function of membrane proteins. EPA and DHA modulate the production of lipid mediators and through effects on cell signalling can alter the patterns of gene expression. Through these mechanisms, EPA and DHA alter cell and tissue responsiveness in a way that often results in more optimal conditions for growth, development and maintenance of health. DHA has vital roles in brain and eye development and function. EPA and DHA have a wide range of physiological roles, which are linked to certain health or clinical benefits, particularly related to CVD, cancer, inflammation and neurocognitive function. The benefits of EPA and DHA are evident throughout the life course. Future research will include better identification of the determinants of variation of responses to increased intake of EPA and DHA; more in-depth dose-response studies of the effects of EPA and DHA; clearer identification of the specific roles of EPA, docosapentaenoic acid and DHA; testing strategies to enhance delivery of n-3 fatty acids to the bloodstream; and exploration of sustainable alternatives to fish-derived very long-chain n-3 fatty acids.

Chemopreventive and Chemotherapeutic Effects of Fish Oil derived Omega-3 Polyunsaturated Fatty Acids on Colon Carcinogenesis

Colorectal cancer is the third most common cause of cancer related death in the world. Multiple lines of evidence suggest that there is an association between consumption of dietary fat and colon cancer risk. Not only the amount but also the type and the ratio of fatty acids comprising dietary fats consumed have been implicated in the etiology and pathogenesis of colon cancer. Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have been known to inhibit development of colon cancer by downregulating the expression of genes involved in colon carcinogenesis and also by altering the membrane lipid composition. Data from laboratory, epidemiological, and clinical studies substantiate the beneficial role of n-3 PUFAs in preventing colitis and subsequent development of colon cancer. In addition, recent studies suggest that some n-3 PUFAs can be effective as an adjuvant with chemotherapeutic agents and other natural anticancer compounds in the management of colon cancer. In this review, we discuss chemopreventive and therapeutic effects of fish oil derived long chain n-3 PUFAs, particularly EPA and DHA, with focus on synergetic effects of which they exert when combined with chemotherapeutic agents and other natural compounds.

Evaluation of Two Dry Commercial Therapeutic Diets for the Management of Feline Chronic Gastroenteropathy

Management of feline chronic gastroenteropathies has included intervention with both veterinary therapeutic formulas designed to manage non-specific gastrointestinal disorders and those designed with limited novel or hydrolyzed ingredients for management of food-responsive enteropathies and steroid-responsive enteropathies (inflammatory bowel disease). There have been few studies evaluating the use of dietary intervention for the management of feline chronic gastroenteropathy. This prospective, multi-center study evaluated the use of two commercially available feline veterinary therapeutic dry diets designed to manage non-specific gastrointestinal disorders in 28 cats with a history of chronic vomiting and/or diarrhea. The majority of cats enrolled in the study had a history of vomiting (n = 25), with a smaller number having a history of concurrent diarrhea (n = 2) or diarrhea alone (n = 3). Cats were excluded if diagnostic tests identified any systemic or infectious disease that could be associated with the clinical signs of vomiting or diarrhea, and if they were panhypoproteinemic, hypoalbuminemic, hypocobalaminemic, or had a Spec fPL ≥5.4 µg/L. Cats were randomized to one of two veterinary therapeutic diets for 4 weeks. Feeding of both therapeutic diets resulted in a numeric reduction in the number of vomiting episodes over the 4-week period, but no significant differences were seen between dietary interventions. When looking within dietary groups, significant differences were seen in cats fed Diet A with reductions of 69.1, 73.3, and 63.2% (p values of 0.008, 0.003, and 0.029) in weeks 2, 3, and 4, respectively, when compared to week 0. The probability of vomiting also showed significant reductions in cats fed Diet A between weeks 0 and 2, 3, and 4, with odds ratios of 0.008, 0.005, and 0.005, respectively (p values of 0.038, 0.23, and 0.23). Results of this study demonstrate that a veterinary therapeutic gastrointestinal formula can be effective in the management of feline chronic vomiting. Cats that fail to respond to this dietary approach after a 2- to 4-week trial may benefit from a limited novel or hydrolyzed ingredient formula and may require additional diagnostics to better characterize the underlying disease.

Preoperative Immunonutrition and Elective Colorectal Resection Outcomes

BACKGROUND

Randomized controlled trials demonstrate the efficacy of arginine-enriched nutritional supplements (immunonutrition) in reducing complications after surgery. The effectiveness of preoperative immunonutrition has not been evaluated in a community setting.

OBJECTIVE

This study aims to determine whether immunonutrition before elective colorectal surgery improves outcomes in the community at large.

DESIGN

This is a prospective cohort study with a propensity score-matched comparative effectiveness evaluation.

SETTINGS

This study was conducted in Washington State hospitals in the Surgical Care Outcomes Assessment Program from 2012 to 2015.

PATIENTS

Adults undergoing elective colorectal surgery were selected.

INTERVENTIONS

Surgeons used a preoperative checklist that recommended that patients take oral immunonutrition (237 mL, 3 times daily) for 5 days before elective colorectal resection.

MAIN OUTCOME MEASURES

Serious adverse events (infection, anastomotic leak, reoperation, and death) and prolonged length of stay were the primary outcomes measured.

RESULTS

Three thousand three hundred seventy-five patients (mean age 59.9 ± 15.2 years, 56% female) underwent elective colorectal surgery. Patients receiving immunonutrition more commonly were in a higher ASA class (III-V, 44% vs 38%; p = 0.01) or required an ostomy (18% vs 14%; p = 0.02). The rate of serious adverse events was 6.8% vs 8.3% (p = 0.25) and the rate of prolonged length of stay was 13.8% vs 17.3% (p = 0.04) in those who did and did not receive immunonutrition. After propensity score matching, covariates were similar among 960 patients. Although differences in serious adverse events were nonsignificant (relative risk, 0.76; 95% CI, 0.49-1.16), prolonged length of stay (relative risk, 0.77; 95% CI, 0.58-1.01 p = 0.05) was lower in those receiving immunonutrition.

LIMITATIONS

Patient compliance with the intervention was not measured. Residual confounding, including surgeon-level heterogeneity, may influence estimates of the effect of immunonutrition.

CONCLUSIONS

Reductions in prolonged length of stay, likely related to fewer complications, support the use of immunonutrition in quality improvement initiatives related to elective colorectal surgery. This population-based study supports previous trials of immunonutrition, but shows a lower magnitude of benefit, perhaps related to compliance or a lower rate of adverse events, highlighting the value of community-based assessments of comparative effectiveness.

Omega-3 polyunsaturated fatty acids in the prevention of postoperative complications in colorectal cancer: a meta-analysis

OBJECTIVE

To evaluate systematically the clinical efficacy of omega-3 polyunsaturated fatty acids (PUFAs) in the prevention of postoperative complications in colorectal cancer (CRC) patients.

MATERIALS AND METHODS

Published articles were identified by using search terms in online databases - PubMed, Embase, and the Cochrane Library - up to March 2016. Only randomized controlled trials investigating the efficacy of omega-3 PUFAs in CRC were selected and analyzed through a meta-analysis. Subgroup, sensitivity, and inverted funnel-plot analyses were also conducted.

RESULTS

Eleven articles with 694 CRC patients were finally included. Compared with control, omega-3 PUFA-enriched enteral or parenteral nutrition during the perioperative period reduced infectious complications (risk ratio [RR] 0.63, 95% confidence interval [CI] 0.47-0.86; P=0.004), tumor necrosis factor alpha (standard mean difference [SMD] -0.37, 95% CI -0.66 to -0.07; P=0.01), interleukin-6 (SMD -0.36, 95% CI -0.66 to -0.07; P=0.02), and hospital stay (MD -2.09, 95% CI -3.71 to -0.48; P=0.01). No significant difference was found in total complications, surgical site infection, or CD4⁺:CD8⁺ cell ratio.

CONCLUSION

Short-term omega-3 PUFA administration was associated with reduced postoperative infectious complications, inflammatory cytokines, and hospital stay after CRC surgery. Due to heterogeneity and relatively small sample size, the optimal timing and route of administration deserve further study.

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.

Conducting omega-3 clinical trials with cardiovascular outcomes: Proceedings of a workshop held at ISSFAL 2014

In contrast to earlier long-chain (LC) omega-3 (i.e. EPA and DHA) investigations, some recent studies have not demonstrated significant effects of EPA and DHA on cardiovascular disease (CVD) outcomes. The neutral findings may have been due to experimental design issues, such as: maintenance on aggressive cardiovascular drug treatment overshadowing the benefits of LC omega-3s, high background LC omega-3 intake, too few subjects in the study, treatment duration too short, insufficient LC omega-3 dosage, increase in omega-6 fatty acid intake during the study, failure to assess the LC omega-3 status of the subjects prior to and during treatment and lack of clarity concerning which mechanisms were expected to produce benefits. At the 11th ISSFAL Congress, a workshop was held on conducting LC omega-3 clinical trials with cardiovascular outcomes, with the goal of gaining a better understanding concerning aspects of experimental design that should be considered when planning clinical studies related to EPA and DHA and potential cardiovascular benefits.

Omega-3 polyunsaturated Fatty acids as potential chemopreventive agent for gastrointestinal cancer

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), particularly eicosapentanoic acid (EPA) and docosahexanoic acid (DHA), has been acknowledged as essential very long-chain fatty acids contributing to either achieving optimal health or protection against diseases, and even longevity. Recent high impact studies dealing with EPA and DHA have sparked a renewed interest in using n-3 PUFAs for cancer prevention and cancer treatment, for which n-3 PUFAs may exert their anticancer actions by influencing multiple targets implicated in various stages of cancer development, including cell proliferation, cell survival, angiogenesis, inflammation, and metastasis against various cancers. However, gastrointestinal cancers develop implicated with the close connection between inflammation and cancer and n-3 PUFAs especially imposed excellent actions of antiinflammation and antioxidation as well as their restorative actions. In detail, these beneficial lipids can restore or modify inflammation-associated lipid distorsion and alteration of lipid rafts. Although the chemopreventive effect of n-3 PUFAs has been studied in various experimental models, our understanding regarding the underlying mechanisms of n-3 PUFAs against GI cancer is still limited. In this review article, we described the in-detailed perspective and underlying mechanism of n-3 PUFAs application for GI cancers and added in vivo efficacy of n-3 PUFAs with Fat-1 transgenic mice experience. We suggest that future work should consider the n-6/n-3 FA ratio, combination treatment of other nutritions and alteration of lipid rafts to be a key element in experimental design and analysis.

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.