Effects of a palmitoleic acid concentrated oil on C-reactive protein levels in adults: A randomized, double-blind placebo-controlled clinical trial.

BACKGROUND

Palmitoleic acid (POA) is an n-7 monounsaturated fatty acid. Preclinical studies suggest cis-POA lowers inflammation and improves metabolism. However, the impact of POA supplementation on inflammatory/metabolic biomarkers in humans is not well understood.

OBJECTIVES

The primary aim was to investigate if cis-POA lowers circulating high-sensitivity C-reactive protein (hs-CRP) relative to placebo. Secondary endpoints were interleukin-6, tumor necrosis factor-α, fasting glucose, insulin, glycosylated hemoglobin, low-density lipoprotein cholesterol, red blood cell (RBC), and plasma fatty acid concentration. Exploratory endpoints were total cholesterol, high-density lipoprotein cholesterol, triglycerides, leptin, ghrelin, peptide YY, and adiponectin.

METHODS

The randomized double-blinded parallel arm trial enrolled 123 participants with hs-CRP concentrations of 2 mg/L or higher. Participants consumed 500 mg/d or 1000 mg/d of marine-source POA or placebo for 12 wk. Fasting blood draws were used to quantify plasma inflammatory/metabolic biomarkers at baseline and 12-wk by multiplex immunoassays. Plasma and RBC POA concentrations were quantified with gas chromatography. Dietary intake was assessed with the Nutrition Data System for Research. Analysis of covariance analysis was used to investigate if there is an effect of either baseline or dosage on inflammatory/metabolic biomarkers.

RESULTS

At baseline, all 3 groups had similar hs-CRP concentrations [geometric mean (standard deviation) = 0.57 (0.17), 0.54 (0.20), and 0.53 (0.23)] at 1000 mg/d, 500 mg/d, and placebo, respectively. There were no changes in hs-CRP concentration within and between the 3 groups in response to the supplementation. Analysis of covariance analysis showed there was no significant influence of baseline hs-CRP or POA dosage on changes in hs-CRP. There were also no changes in secondary or exploratory endpoints in response to placebo or POA. Significant changes were measured in select plasma and RBC fatty acids that were significantly related to POA dosage (P < 0.001) but not baseline.

CONCLUSIONS

Compared to placebo, supplementation for 12 wk with 500 mg/d or 1000 mg/d POA did not significantly lower hs-CRP or change other biomarkers.