Gastrointestinal cancer: omega-3s reduce postoperative recovery

In patients with cancer of the gastrointestinal tract and undergoing surgery, omega-3 supplements stimulate immune function, reduce inflammation, and improve nutritional status, thereby facilitating recovery and reducing hospitalization time. Although further studies are needed to confirm these positive effects, the use of EPA and DHA supplements is recommended for the management of the postoperative period.

This is according to a recent study conducted by researchers at Capital Medical University in Beijing, China, and published in the journal BMC Cancer.

Gastrointestinal tract cancer: malnutrition among postoperative complications

Different types of cancers of the digestive system are the leading cause of cancer deaths, worldwide. Malignant cancers of the digestive system include cancer of the esophagus, stomach, intestines, liver and pancreas. Surgery is the main treatment for patients with cancer in the early stage. However, those who undergo surgery are at risk of developing some postoperative complications such as malnutrition, tumor-induced immune suppression, surgical stress, and inflammation. Postoperative complications affect clinical outcome in digestive tract cancer patients, and consequently hospital stay and related health care costs. 

Among various symptoms, malnutrition is the most important factor influencing clinical prognosis. In fact, recent studies indicate that nutritional support may reduce the incidence of adverse events after surgery in gastrointestinal tract cancer patients. In this context, polyunsaturated fatty acids may promote recovery after surgery due to their beneficial properties. In fact, omega-3s modulate the level of inflammation, reduce oxidative stress and complications of surgery; the results of some studies indicate that the anti-inflammatory effect of EPA and DHA promotes wound healing and enhances the adaptive immune response. However, the interpretation of these studies is problematic because of methodological limitations and small sample sizes examined. In addition, the results of some recent research are contradictory and need further investigation.

Less inflammation and more active immune system after omega-3 supplementation

In order to clarify the potential role of omega-3s in cancer patients after surgery, Chinese researchers conducted a meta-analysis study, which pooled and analyzed data from a number of scientific studies that had reported the effects of EPA and DHA on some key molecules of inflammation and the immune system. The results, overall, showed that patients who had followed omega-3 supplementation had lower levels of inflammatory substances than those who had not consumed supplements, as well as, they showed higher amounts of immune system molecules, suggesting that omega-3s had significantly reduced the level of inflammation and stimulated the body's defense functions. According to the researchers who conducted the study, modulation of immune responses and reduction of inflammation together are able to reduce postoperative hospitalization time in patients with cancers of the gastrointestinal tract. In addition, again according to the researchers, it is preferable to start nutritional support with omega-3s five to seven days before surgery and continue in the postoperative period.

The details of the study

The meta-analysis study was conducted by examining the results of nine clinical trials with a total of 623 patients. The conclusions obtained report that omega-3 supplements are beneficial for subjects with cancer of the gastrointestinal tract by reducing the level of inflammatory cytokines, including IL-2, IL-6 and TNF-α, and promoting the activity of anti-inflammatory molecules by stimulating healing. High consumption of EPA and DHA was found to be closely correlated with a reduction in the level of CRP (a protein produced by the liver during the inflammatory state), indicative of a better prognosis. The meta-analysis also showed that omega-3s effectively increased the level of T lymphocytes, indicating that the immune system response was improved after surgery. According to the researchers themselves, the study has numerous limitations. For example, omega-3 consumption varies widely between countries, which could explain the difference in results between one study and another. Estimates of the results were taken from published data, therefore, systematic limitations could not be minimized and the data, in some cases, were incomplete.

Omega-3s reduce hospitalization

Despite the above objections, the effects of omega-3s in the postoperative phase of gastrointestinal cancer patients are positive; in fact, the scientists who carried out the research concluded that supplementation with EPA and DHA can improve immune function and reduce the level of inflammation, accelerating recovery after surgery. 

Source: Jing Yu, et al. "Effects of omega-3 fatty acids on patients undergoing surgery for gastrointestinal malignancy: a systematic review and meta-analysis." BMC Cancer.