Moderate intensity exercise has been shown to prevent the development and progression of chronic inflammatory diseases, including type 2 diabetes. Likewise, physical fitness is associated with reduced inflammation, morbidity, and mortality. Nonetheless, factors that contribute to the anti-inflammatory effect of physical fitness remain largely undefined. Using data collected from 437 participants in the 2003-2004 National Health and Nutrition Examination Survey, we assessed how the omega-6/omega-3 fatty acid ratio (ω-6/ω-3) modifies the relationship between cardiorespiratory fitness (VO2max) and inflammation (C-reactive protein; CRP). Participants were 45% female with an average age of 32.9 years and with a BMI of 27.7 kg/m2. In adjusted models for CRP, we observed significant interactions between VO2max and ω-6/ω-3 quartiles. Participants with the highest quartile of ω-6/ω-3 showed a positive association between VO2max and CRP levels. Conversely, the lowest quartiles of ω-6/ω-3 were negatively associated with VO2max and CRP, ranging from -22.4% to -33.7% CRP per 10 ml/kg/min VO2max compared with the highest ω-6/ω-3 quartile (interaction p-value= 0.0149). This negative relationship was strengthened when alternatively modeling the interaction between total ω-3 levels and VO2max (interaction p-value=0.0002), wherein higher ω-3 levels resulted in a stronger negative association between VO2max and CRP. This was predominantly driven by alpha-linoleic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), but not docosapentaenoic acid (DPAn-3) levels. We also observed negative associations between circulating levels of monocytes and VO2max for participants with lower ω-6/ω-3 or higher ω-3 EPA levels. Collectively, these data suggest that the anti-inflammatory effect of physical fitness is enhanced with higher plasma levels of ω-3 fatty acids.
G. Farley: None. D.W. Riggs: None. A. Bhatnagar: None. J. Hellmann: None.
National Institutes of Health (GM127495, GM127607)