Asthma risk in children and adolescents may be reduced via dietary intake of n-3 polyunsaturated fatty acids (PUFAs), according to study findings published in Pediatric Allergy and Immunology.
Prior studies exploring the relationship between n-3 PUFA dietary intake and childhood asthma have reported inconsistent results, with some suggesting potential associations between higher intake and reduced asthma risk, and others failing to note significant associations. Investigators therefore sought to assess the association between intake of dietary n-3 PUFAs and asthma in children and adolescents in the US.
This cross-sectional analysis included data from 2013 and 2020 on 8543 children and adolescents who took part in the National Health and Nutrition Examination Survey (NHANES), a US survey aimed at evaluating nutritional status and health of noninstitutionalized individuals.
The researchers assessed covariates that included sex, age, race and ethnicity, body mass index (BMI), and familial asthma, as well as daily intake of protein, sugar, fat, and saturated fatty acids. Participants older than 20 years of age, children with missing asthma questionnaires, and children missing dietary n-3 PUFA intake data were excluded. Those in the asthma group were older and tended to be boys, with a greater proportion of non-Hispanic Black participants and a lower proportion of non-Hispanic White participants.
Overall, 1456/8543 participants (16.5%) self-reported that an asthma diagnosis had been given by a health care provider. Statistically significant differences in sex, age, race and ethnicity, BMI, familial asthma, as well as daily intake of protein, sugar, fat, and saturated fatty acids were noted between the asthma and non-asthma groups.
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Dietary intake of n-3 PUFAs exhibited an L-shaped relationship with asthma in children and adolescents in the United States, with a critical turning point observed at approximately 59.0 mg/kg/day.
The investigators adjusted for potential confounders, then compared participants in the lowest n-3 PUFA consumption group (tier 1, n-3 PUFA consumption <26.07 mg/kg/day) with participants in higher n-3 PUFA consumption groups. In the second group (tier 2, consumption 26.07-48.93 mg/kg/day), the adjusted odds ratio (aOR) for asthma was 0.71 (95% CI, 0.60-0.84). In the third group (tier 3, consumption >48.93 mg/kg/day) the aOR for asthma was 0.58 (95% CI, 0.47-0.73) (all P <.001).
The investigators found an L-shaped relationship between n-3 PUFA intake and asthma (P =.009) with the critical turning point about 59.0 mg/kg/day (aOR<59.0 mg/kg/day, 0.984; 95% CI, 0.977-0.991; P <.0010; and aOR≥59.0 mg/kg/day, 1.001; 95% CI, 0.993-1.009; P =.7479). This means that with daily intake of n-3 PUFAs below 59.0 mg/kg/day, each 1 mg/kg/day increase in n-3 intake associated with a 1.6% risk reduction for developing asthma, but no significant correlation was noted between dietary n-3 PUFA intake and risk for asthma when intake exceeded 59.0 mg/kg/day.
Study limitations include residual confounding and recall bias in self-reporting.
“Dietary intake of n-3 PUFAs exhibited an L-shaped relationship with asthma in children and adolescents in the United States, with a critical turning point observed at approximately 59.0 mg/kg/day,” the study authors noted. “When the daily intake of n-3
PUFAs was below 59.0 mg/kg, each 1 mg/kg/day increase in n-3 PUFA intake was associated with a 1.6% reduction in the risk of developing asthma… However, no significant correlation was found between dietary n-3 PUFA intake and asthma risk when n-3 PUFA intake exceeded 59.0 mg/kg/day.”
