Subgroup analysis revealed that increasing dietary ALA tends to elevate CRP concentration  in healthy subjects .
However , the null effect of ALA supplementation on other inflammatory markers was not changed in various subgroups , indicating that the results are stable .
Meta-regression results revealed a negative relationship between the effect size on CRP and its baseline concentration .
No significant publication bias was observed for all inflammatory markers as suggested by funnel plot and Begg ’s test .
Conclusion Our meta- analysis did not find any beneficial effect of ALA supplementation  on reducing inflammatory markers including TNF , IL-6 , CRP , sICAM-1 , and sVCAM-1 .
However , in healthy subjects  , ALA supplementation might increase CRP concentration
Purpose The aim of the current meta- analysis was to investigate the effect of increasing dietary ALA intake on the blood concentration of inflammatory markers including tumor necrosis factor ( TNF ) , interleukin 6 ( IL-6 ) , C-reactive protein ( CRP ) , soluble intercellular adhesion molecule-1 ( sICAM-1 ) , and soluble vascular cell adhesion molecule-1 ( sVCAM-1 )  in adults .
Influence of dietary supplementation with long-chain n−3 or n−6 polyunsaturated fatty acids on blood inflammatory cell populations and functions and on plasma soluble adhesion molecules in healthy adults
Greatly increasing the amounts of flaxseed oil [ rich in α-linolenic acid ( ALNA ) ] or fish oil ( FO ) ; [ rich in eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ) ] in the diet can decrease inflammatory cell functions and so might impair host defense . The objective of this study was to determine the effect of dietary supplementation with moderate levels of ALNA , γ-linolenic acid ( GLA ) , arachidonic acid ( ARA ) , DHA , or FO on inflammatory cell numbers and functions and on circulating levels of soluble adhesion molecules .  Healthy subjects aged 55 to 75 yr consumed nine capsules per day for 12 wk . The capsules contained placebo oil ( an 80∶20 mix of palm and sunflowerseed oils ) or blends of placebo oil with oils rich in ALNA , GLA , ARA , or DHA or FO . Subjects in these groups consumed 2 g ALNA ; approximately 700 mg GLA , ARA , or DHA ; or 1 g EPA plus DHA ( 720 mg EPA+280 mg DHA ) daily from the capsules . Total fat intake from the capsules was 4 g per day . None of the treatments affected inflammatory cell numbers in the bloodstream ; neutrophil and monocyte phagocytosis or respiratory burst in response to E. coli ; production of tumor necrosis factor-α , interleukin-1β , and interleukin-6 in response to bacterial lipopolysaccharide ; or plasma concentrations of soluble intercellular adhesion molecule-1 . In contrast , the ALNA and FO treatments decreased the plasma concentrations of soluble vascular cell adhesion molecule-1 ( 16 and 28 % decrease , respectively ) and soluble E-selectin ( 23 and 17 % decrease , respectively ) . It is concluded that , in contrast to previous reports using higher amounts of these fatty acids , a moderate increase in consumption of long-chain n−6 or n−3 polyunsaturated fatty acids does not significantly affect inflammatory cell numbers or neutrophil and monocyte responses in humans and so would not be expected to cause immune impairment . Furthermore , we conclude that moderate levels of ALNA and FO , which could be incorporated into the diet , can decrease some markers of endothelial activation and that this mechanism of action may contribute to the reported health benefits of n−3 fatty acids
Subgroup analysis revealed that increasing dietary ALA tends to elevate CRP concentration  in healthy subjects .
However , the null effect of ALA supplementation on other inflammatory markers was not changed in various subgroups , indicating that the results are stable .
Meta-regression results revealed a negative relationship between the effect size on CRP and its baseline concentration .
No significant publication bias was observed for all inflammatory markers as suggested by funnel plot and Begg ’s test .
Conclusion Our meta- analysis did not find any beneficial effect of ALA supplementation  on reducing inflammatory markers including TNF , IL-6 , CRP , sICAM-1 , and sVCAM-1 .
However , in healthy subjects  , ALA supplementation might increase CRP concentration
Purpose The aim of the current meta- analysis was to investigate the effect of increasing dietary ALA intake on the blood concentration of inflammatory markers including tumor necrosis factor ( TNF ) , interleukin 6 ( IL-6 ) , C-reactive protein ( CRP ) , soluble intercellular adhesion molecule-1 ( sICAM-1 ) , and soluble vascular cell adhesion molecule-1 ( sVCAM-1 )  in adults .