Secondhand Smoke Exposure Significantly Associated With Headache, Migraines

Heavy secondhand smoke (SHS) exposure could increase risk of severe headaches or migraines in people who have never smoked, according to a cross-sectional study published in the journal Headache. 

“These findings underscore the harmful impact of [secondhand smoke] exposure on the nervous system and serve as a reminder to avoid prolonged exposure to tobacco smoke,” researchers concluded.

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Authors pulled and examined data on 4560 never-smoking adults from the National Health and Nutrition Examination Survey (NHANES), 1999–2004. SHS exposure was measured using serum cotinine concentrations, a chemical that forms in the body after nicotine exposure. According to the Environmental Protection Agency (EPA), active smokers typically have serum cotinine levels over 10 nanograms per milliliter (ng/mL), “while non-smokers exposed to typical levels of secondhand smoke have serum concentrations less than 1 ng/mL.” Headache data was self-reported by participants.

Heavy SHS exposure, serum cotinine at 1 to 10 ng/mL, was associated with severe headaches or migraine (OR: 2.02, 95% CI [1.19, 3.43]). No significant association was found between low SHS exposure—serum cotinine at 0.05 to 0.99 ng/mL—and headaches or migraine (OR: 1.15, 95% CI [0.91, 1.47]). Restricted cubic spline analysis showed that the natural logarithm of serum cotinine had a linear relationship with severe headaches or migraine (p = 0.335 for nonlinearity).

However, authors noted that this study’s results could be preliminary and that “prospective studies are necessary to verify this relationship in the future.”
 

References
Wu J, Yang P, Wu X, et al. Association between secondhand smoke exposure and severe headaches or migraine in never-smoking adults. Headache. 2023;63(10):1341-1350. doi:10.1111/head.14640

Serum Cotinine. Environmental report. Environmental Protection Agency. Accessed January 24, 2024.