TABLE 4

Associations between maternal dietary antioxidant intake and childhood outcomes stratified by maternal smoking during pregnancy

	Asthma		Atopy		FEV₁		FVC		FEF₂₅₋₇₅
	OR^# (95% CI)	p_trend	OR^# (95% CI)	p_trend	β^# (95% CI)	p_trend	β^# (95% CI)	p_trend	β^# (95% CI)	p_trend
Subjects n	7677		6117		6062		6157		6157
Total fruits intake
Non/passive smokers	0.99 (0.89–1.09)	0.81	1.02 (0.93–1.12)	0.61	0.02 (−0.02–0.05)	0.41	0.02 (−0.02–0.05)	0.35	0.01 (−0.02–0.05)	0.43
Active smokers	0.90 (0.78–1.04)	0.16	0.87 (0.76–1.01)	0.07	0.02 (−0.04–0.08)	0.49	0.02 (−0.04–0.08)	0.45	0.00 (−0.06–0.06)	1.00
p_interaction^¶	0.59		0.14		0.60		0.90		0.93
Total vegetables intake
Non/passive smokers	1.00 (0.92–1.08)	0.91	0.99 (0.93–1.06)	0.85	0.02 (−0.01–0.05)	0.15	0.02 (−0.01–0.05)	0.16	0.02 (−0.01–0.04)	0.23
Active smokers	0.88 (0.78–1.00)	0.05	0.94 (0.83–1.07)	0.34	0.02 (−0.03–0.07)	0.36	0.00 (−0.05–0.05)	0.96	0.04 (0.00–0.09)	0.07
p_interaction^¶	0.18		0.70		0.96		0.35		0.25
Vitamin C intake
Non/passive smokers	1.00 (0.92–1.09)	0.99	1.01 (0.94–1.09)	0.75	0.00 (−0.03–0.03)	0.81	0.01 (−0.02–0.04)	0.53	0.00 (−0.03–0.03)	0.86
Active smokers	0.92 (0.81–1.05)	0.23	0.93 (0.82–1.06)	0.30	0.02 (−0.03–0.07)	0.49	0.00 (−0.05–0.05)	0.95	0.02 (−0.03–0.07)	0.41
p_interaction^¶	0.54		0.57		0.55		0.65		0.30
Vitamin E intake
Non/passive smokers	1.06 (0.97–1.16)	0.19	0.97 (0.90–1.05)	0.44	0.00 (−0.03–0.03)	0.96	0.02 (−0.01–0.05)	0.25	−0.01 (−0.05–0.02)	0.38
Active smokers	0.96 (0.84–1.11)	0.60	1.12 (0.98–1.28)	0.11	0.00 (−0.06–0.05)	0.91	0.00 (−0.05–0.05)	0.95	0.00 (−0.05–0.06)	0.94
p_interaction^¶	0.39		0.09		0.83		0.51		0.53
Zinc intake
Non/passive smokers	1.06 (0.94–1.19)	0.36	0.96 (0.86–1.06)	0.39	0.04 (0.00–0.08)	0.05	0.05 (0.01–0.09)	0.02	0.01 (−0.03–0.05)	0.58
Active smokers	1.01 (0.85–1.21)	0.90	1.01 (0.85–1.21)	0.90	0.05 (−0.02–0.12)	0.15	0.05 (−0.02–0.12)	0.14	0.04 (−0.03–0.11)	0.30
p_interaction^¶	0.92		0.61		0.74		0.72		0.76
Selenium intake
Non/passive smokers	0.99 (0.90–1.10)	0.87	0.93 (0.86–1.02)	0.12	0.03 (−0.01–0.06)	0.13	0.03 (0.00–0.07)	0.07	0.01 (−0.03–0.04)	0.76
Active smokers	1.05 (0.90–1.22)	0.56	1.03 (0.89–1.19)	0.72	0.00 (−0.06–0.06)	0.93	0.03 (−0.03–0.08)	0.40	−0.01 (−0.07–0.04)	0.64
p_interaction^¶	0.50		0.31		0.32		0.52		0.67
Carotene intake
Non/passive smokers	0.98 (0.91–1.07)	0.70	0.98 (0.91–1.05)	0.53	0.02 (0.00–0.05)	0.10	0.02 (−0.01–0.05)	0.12	0.01 (−0.02–0.04)	0.52
Active smokers	0.97 (0.85–1.10)	0.59	1.02 (0.90–1.15)	0.78	0.04 (−0.01–0.09)	0.11	0.03 (−0.02–0.08)	0.25	0.04 (−0.01–0.08)	0.15
p_interaction^¶	0.83		0.47		0.75		0.85		0.32
Antioxidant score
Non/passive smokers	1.01 (0.91–1.13)	0.85	0.96 (0.87–1.05)	0.35	0.03 (−0.01–0.07)	0.18	0.04 (0.00–0.08)	0.03	0.00 (−0.04–0.04)	0.93
Active smokers	0.94 (0.80–1.11)	0.44	1.08 (0.92–1.27)	0.37	0.05 (−0.01–0.11)	0.13	0.04 (−0.03–0.10)	0.23	0.04 (−0.02–0.10)	0.22
p_interaction^¶	0.70		0.25		0.86		0.64		0.35

β: difference in age-, height- and sex-adjusted sd units; FEV₁: forced expiratory volume in 1 s; FVC: forced vital capacity; FEF_25–75: forced expiratory flow at 25–75% of FVC. ^#: per category/quartile of dietary intake, controlling for energy intake, infections, supplements, antibiotics and paracetamol use during pregnancy, and maternal educational level, housing tenure, financial difficulties, ethnicity, age, parity, history of atopic diseases, anxiety, sex of child, season of birth, multiple pregnancy and breastfeeding duration; ^¶: treating smoking as a binary variable and dietary exposures as continuous variables.