Parental Smoking Increases Risk of Allergic Diseases in Children, reveals research
According to a recent study published in Allergy Asthma & Clinical Immunology, smoking parents, especially a mother who smokes during her child's infancy, increase the chances of allergy development in her children. This study was conducted by Kenji S. and fellow researchers in Japan.
Allergic diseases are increasingly prevalent in Japan, and the trend has been for the diseases to present earlier in life in children. Although it is known that passive smoking is detrimental to children's health, the control of smoking inside homes continues to be a difficult task. This study had a sample from a Japanese national longitudinal survey containing 38,444 children whose births occurred during the period from May 10 to May 24, 2010.
Smoker status from the parents at 6 months old was measured with follow-up information on the progression of allergic diseases until the participants were 5.5 years old. Poisson regression with robust error variance estimates RRs with 95% CIs across various allergic conditions while adjusting for confounding.
Results
Allergic Rhinitis and Conjunctivitis (AR/AC):
• Maternal smoking increased the risk of AR/AC in children.
• ≤10 cigarettes/day: RR 1.15, 95% CI 1.02–1.30
• ≥11 cigarettes/day: RR 1.16, 95% CI 0.93–1.44
Bronchial Asthma:
• Maternal smoking in the presence of paternal smoking significantly increased the risk.
• ≤10 cigarettes/day: RR 1.33, 95% CI 1.17–1.52
• ≥11 cigarettes/day: RR 1.71, 95% CI 1.38–2.1
Food Allergy:
• Risk was also increased with maternal smoking in combination with paternal smoking.
• ≤10 cigarettes/day: RR 1.36, 95% CI 1.12–1.63
• ≥11 cigarettes/day: RR 1.25, 95% CI 0.84–1.86
Atopic Dermatitis:
• A higher risk was observed for children of mothers who smoked.
• ≤10 cigarettes/day: RR 1.42, 95% CI 1.22–1.66
• ≥11 cigarettes/day: RR 1.60, 95% CI 1.20–2.13
Combined Risk of AR/AC with Paternal Smoking:
• Maternal smoking further amplified the risk of AR/AC in the presence of paternal smoking.
• ≤10 cigarettes/day: RR 1.21, 95% CI 1.07–1.36
• ≥11 cigarettes/day: RR 1.35, 95% CI 1.09–1.67
Maternal smoking during infancy substantially increases the risk of allergic diseases in children, particularly if their father also smokes. Thus, it points to a need for smoke-free homes and further underscores efforts at minimizing parental smoking for better protection of the health and well-being of future generations.
Reference:
Shigehara K, Matsumoto N, Tsuge M, Uda K, Saito Y, Yashiro M, Yorifuji T, Ikeda M, Tsukahara H. Maternal smoking during infancy increases the risk of allergic diseases in children: a nationwide longitudinal survey in Japan. Allergy Asthma Clin Immunol. 2025 Jan 16;21(1):4. doi: 10.1186/s13223-025-00952-9. PMID: 39825417; PMCID: PMC11740415.
