J Pain. 2022 Oct 20;S1526-5900(22)00434-5. doi: 10.1016/j.jpain.2022.10.008.Online ahead of print.

Anne E Sanders ¹, E Diane Weatherspoon ², Brandie M Ehrmann ², Paul S Soma ², Saame R Shaikh ³, John S Preisser ⁴, Richard Ohrbach ⁵, Roger B Fillingim ⁶, Gary D Slade ⁷

Author information

¹Division of Pediatric and Public Health, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Electronic address: anne_sanders@unc.edu.

²Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.

³Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.

⁴Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.

⁵Department of Oral Diagnostic Sciences, University at Buffalo, Buffalo, New York.

⁶Department of Community Dentistry and Behavioral Science, University of Florida, Gainesville, Florida; Pain Research and Intervention Center of Excellence, Department of Community Dentistry and Behavioral Science, College of Dentistry, University of Florida, Gainesville, Florida.

⁷Division of Pediatric and Public Health, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.

Abstract

Pain intensity is well-known to be influenced by a wide range of biobehavioral variables. Nutritional factors, however, have not been generally considered for their potential importance. This cross-sectional study examined associations between erythrocyte omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and pain intensity in 605 adults. Pain intensity was computed on a 0 to 100 numeric rating scale from questions about 5 chronic pain conditions: orofacial pain, headache, low back pain, irritable bowel syndrome, and bodily pain. For each pain condition, multiple linear regression tested the hypothesis that a higher ratio of n-6 arachidonic acid to the sum of n-3 eicosapentaenoic acid and docosahexaenoic acid (AA/(EPA+DHA) was associated with greater pain intensity. In covariate-adjusted analysis, orofacial pain intensity increased 5.7 points (95% CI: 1.4, 9.9) per unit increase in n-6/n-3 PUFA ratio. Likewise, a 1 unit increase in n-6/n-3 PUFA ratio was associated with significant increases in pain intensity (range 5-8 points) of headache pain, low back pain, and bodily pain, but not abdominal pain. Separate multiple linear regression models investigated the independent strength of association of individual PUFAs to the intensity of each pain condition. Overall, n-3 docosahexaenoic acid was most strongly, and inversely, associated with pain intensity. PERSPECTIVE: A higher ratio of n-6/n-3 long-chain polyunsaturated fatty acids was associated greater pain intensity for orofacial pain, headache, low back pain, and bodily pain, but not abdominal pain. The n-6/n-3 PUFA ratio was more consistently associated with pain intensity than any individual constituent of the long-chain PUFA ratio.