The effect of conjugated linoleic acid supplementation on the nutritional status of COPD patients

BACKGROUND COPD patients are susceptible to anorexia, reduction of caloric intake, weight loss, and malnutrition. One of the possible mechanisms is the increase of inflammatory markers such as interleukin 1β (IL1β), is highly correlated with anorexia. Considering the anti-inflammatory role of conjugated linoleic acid (CLA), this study aimed to investigate the effect of CLA supplementation on the nutritional status of COPD patients. PATIENTS AND METHODS In a double-blind clinical trial, 93 COPD patients who volunteered to participate in the study and who filled out a written consent form, were randomly assigned to control or supplementation groups. The patients in the supplementation group received 3.2 g of CLA on a daily basis for 6 weeks, while those in the control group received placebo on a daily basis for 6 weeks. For IL1β assessment, the patients' anthropometric indices and appetite score were checked and their blood samples were collected both before and after the treatment. Moreover, in order to investigate the changes in the caloric intake trend during the study, their dietary intake levels were assessed using 24-hour dietary recall, 3 days a week at the onset, in the 4th week, and at the end of the study. Eventually, 90 patients completed the study. RESULTS The results demonstrated a significant increase in appetite score (P=0.001), average caloric intake (P=0.01), and macronutrient intake (P<0.05), while a significant decrease was observed in the serum level of IL1β among the patients of the supplementation group (P=0.008). Meanwhile, although the supplementation group's body mass index was also higher on completion, compared to their own initial state as well as to that in the control group, the differences were not significant (P=0.13). CONCLUSION The findings of this research indicate that the consumption of CLA supplementation can be effective in regulating the appetite and improving the nutritional status of patients suffering from COPD through adjusting the serum level of IL1β.