This article is more than 5 years old. Information may no longer be current.
Fish oil supplementation does not lower levels of inflammation biomarkers
An investigation of n-3 polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid found that they did not reduce C-reactive protein or interleukin-6 levels in healthy adults, according to research published in the Journal of Internal Medicine.
Matthew F. Muldoon, MD, MPH, Heart and Vascular Institute, University of Pittsburgh School of Medicine, and colleagues conducted an exploratory single-site, randomized, double-blind, placebo-controlled trial to assess whether 261 healthy adults with diets low in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) would see a reduction in two markers of chronic inflammation: C-reactive protein (CRP) and interleukin-6 (IL-6). The researchers also collected blood samples from 116 participants to evaluate ex vivo pro-inflammatory cytokine production.
Participants were aged 30 to 54 years and were selected from the Adult Health and Behavior Project — Phase 2. Participants randomly assigned to the fish oil group received two 1,000-mg capsules per day, which provided them with 1,000 mg EPA and 400 mg DHA. Participants randomly assigned to the placebo group received 1,000-mg soybean oil capsules which contained 1% fish oil. Both capsules contained 10 IU vitamin E and mint flavoring.
Results showed that the mean concentration of EPA+DHA in red blood cells of participants who took the placebo were unchanged at 2.85 nmol mL-1 (P = .89) after 18 weeks of supplementation. The mean concentration of EPA+DHA in red blood cells of participants who took fish oil increased by 64% to 4.95 ± 1.59 nmol mL-1 (P < .001).
Muldoon and colleagues reported no changes in CRP levels (MD = 0.183 mg L-1; 95% CI, –0.098 to 0.464; P = .21) or IL-6 levels (MD = 0.037 pg mL-1; 95% CI, –0.268 to 0.194; P = .59) after supplementation.
Supplementation with fish oil did not affect ex vivo production of tumor necrosis factor-alpha (MD = 313 pg mL1; 95% CI, 1673 to 2298; P = 0.81), IL-1 (MD = 13.3 pg mL1; 95% CI, 70.9 to 97.4; P = 0.99), IL-8 (MD = 1.65 g mL1; 95% CI, 12.16 to 8.85; P = 0.2) or IL-6 (MD = 12.2 ng mL1; 95% CI, 89.8 to 65.4; P = 0.43).
"This finding corroborates previous reports," Muldoon and colleagues wrote. "On the other hand, a range of biological actions of the n-3 fatty acids within inflammatory cascades is well documented, and other measures of immune function, regulators of inflammation and biomediators of oxidative stress may reveal actions not detected by serum CRP and IL-6 levels.
Furthermore, daily doses of 2,000mg per day, in contrast to lower amounts, may have measureable physiological effects. If this is the case, however, the requirement of such a high dose would diminish the feasibility of widespread primary prevention through raised consumption of fish or n-3 polyunsaturated fatty acid supplements." – by Chelsea Frajerman Pardes
Disclosures: The authors report no relevant financial disclosures.