The effect of n-3 polyunsaturated fatty acids on inflammation status in cancer patients: Updated systematic review and dose- and time-response meta-analysis

Background: Reducing inflammation levels can potentially reduce treatment-induced complications in cancer patients. This meta-analysis aimed to determine the effect of n-3 PUFAs on three main biomarkers of inflammation: tumor necrosis factor-alpha(TNF-alpha), C-reactive protein (CRP), and interleukin-6 (IL-6). Methods: A systematic search was conducted on PubMed, Scopus, and the Web of Science databases to find relevant studies. The difference between the intervention and control arms results was assessed by standardized mean differences (SMD) along with a 95% confidence interval. Result: The study found that the SMD for TNF-alpha, CRP, and IL-6 was -0.63(95%CI:-0.89,-0.37, P < 0.001), -0.27(95%CI:-0.64,0.10, P = 0.15), -0.59(95%CI:-0.89,-0.29, P < 0.001) respectively, comparing the effects of n-3 PUFAs on study subjects compared to control. Subgroup analyses revealed heterogeneity sources for TNF-alpha and IL-6 but not for CRP. The study did not detect any indication of publication bias in the cases of TNF-alpha and CRP but detected it for IL-6. Conclusion: N-3 PUFAs caused a significant reduction in levels of TNF-alpha IL-6 but not CRP in cancer patients. The findings support that n-3 PUFAs could be used as an add-on treatment for cancer patients, possibly because they reduce inflammation and do not have any known side effects in moderate doses.