EPA preserves muscle mass post surgery

Clinical Update: Nutrition – The Annals of Surgery recently published a report on research involving patients undergoing surgery for oesophageal cancer, a procedure normally associated with significant weight-loss and quality-of-life issues

. The lead investigators of the study were Prof John V. Reynolds, Professor of Surgery at Trinity College Dublin and Dr Aoife Ryan, Assistant Professor of Nutrition at New York University.
Previous studies on inoperable cancers (for example, pancreatic or lung cancer) have found that eicosapentaenoic acid (EPA) reduced weight loss and improved physical activity and quality of life. Researchers hypothesised that a nutritional supplement rich in calories and a high dose of EPA would stem the debilitating weight loss seen in patients following oesophageal cancer surgery.
A study performed at St James’s Hospital was the first to investigate if giving EPA-supplemented early enteral nutrition (Prosure) would work in the context of a big surgical insult to the body.
Normally after an oeso-phagectomy, eating is not possible for up to ten days and subsequently, appetite can be poor for several weeks. Tube feeding into the small bowel is routine in many centres in the weeks that follow surgery. Once the tube is removed, intake can remain poor for many months and unintentional weight-loss can be significant, continuing for up to six months after surgery. Publications by Prof Reynolds at Dublin’s St James’s Hospital have previously shown that quality of life also dips significantly in the months following discharge.
In a double-blinded randomised control trial, the gold standard in medical research, patients awaiting oesophagectomy surgery for cancer were randomly assigned to treatment and control groups. While both groups received a 240ml nutritional supplement twice daily starting five days before surgery (which was identical in calories, protein, micronutrients and flavour), patients in the treatment group received an enriched formula with omega 3 (2.2 gram EPA/day).
Immediately following surgery, the supplement was given through a feeding tube into the small intestine for 14 days while patients recovered in hospital. Once patients could resume oral feeding, they continued drinking the supplement until 21 days post-surgery.
The researchers working at St James’s Hospital and Trinity College Dublin found that patients given the standard feed (without EPA) suffered clinically severe weight-loss post surgery which was all muscle mass, losing an average of five pounds of muscle from the arms, legs and chest within three weeks, while patients in the treatment group maintained all aspects of their body composition following surgery.
Gas chromatography was employed to look at immune cells in the lab – levels of EPA rose significantly in the cell membranes of neutrophil immune cells. They did not in the standard group. In the treatment group, the drop in natural killer cells that appears after surgery appeared to be prevented.
Some benefits were noted in terms of a shift towards the production of helper T cells – there was an increase in the ratio of these to cytotoxic T cells.
The pro-inflammatory cytokines IL-6, IL-8 and IL-10 were also dampened down. The treatment appeared to get patients back on the road to anabolism faster. “The results are intriguing; no previous study of nutritional support in the perioperative period has revealed such a benefit,” said Dr Ryan.
Under Prof Reynolds, recruitment will begin shortly for a follow-up trial, to examine the long-term outcomes of EPA-enriched nutrition on physical activity and quality of life scores.
The study, which has attracted sponsorship from Abbott Laboratories, will involve a greater number of patients. Sophisticated pedometers will be used to see how much time patients spend sitting, lying and walking once they are discharged from hospital.
“Future studies on the health benefits of EPA supplements in cancer patients should be conducted,” said Prof Reynolds.
“These would determine whether such approaches improve quality of life, reduce complications and improve patient outcomes, not only post-surgery but also through long and complex treatment programmes that may include chemotherapy and radiation therapy in addition to surgery.”