Associação entre asma e consumo de ácidos graxos poli-insaturados ômega-3 e ômega-6 em adolescentes brasileiros

Abstract

Asthma prevalence among adolescents in Brazil is high, and has been increasing in the last few decades. Sociodemographic and environmental factors related to lifestyle changes that occurred in the same period may have contributed to this finding. Among these changes, diet stands out, with increased consumption of refined sugars, fats, meats, and ultra-processed foods, contrasted with less frequent intake of cereals, fruits, vegetables, and fish, leading to a higher proportion of omega-6 (N6) polyunsaturated fatty acids (PUFAs) compared to omega-3 (N3). These lipids are the primary PUFAs in the human diet and are involved in immune response regulation as substrates for the formation of bioactive substances that modulate the inflammatory response. N6 is a precursor of eicosanoids with well-known pro-inflammatory action, while N3 contributes to the formation of lipid mediators with immunoresolvent action. Thus, a diet richer in N3, in contrast to N6, may be protective against the development of chronic inflammatory diseases such as asthma. Therefore, the aim of this study was to investigate the association between asthma and, N3, and N6. This is a cross sectional study using data from the Cardiovascular Risk Study in Adolescents (ERICA), a national, school-based, multicenter survey with a representative sample of Brazilian adolescents (aged 12 to 17). The study aimed to evaluate the prevalence of diabetes mellitus, obesity, cardiovascular risk factors, as well as markers of inflammation and insulin resistance in adolescents. Participants completed questionnaires collecting sociodemographic data, physical activity, smoking habits, dietary recall, and medical history, and underwent anthropometric measurements and blood sample collection. The presence of asthma was defined as having experienced at least one wheezing episode in the past 12 months. The intake of alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) from the omega-3 (N3) series, and linoleic acid (LA) and arachidonic acid (ARA) from the omega-6 (N6) series, as well as the N6/N3 ratio (sum of LA and ARA over ALA, DHA, and EPA), were estimated as continuous variables. The odds ratio (OR) and respective 95% confidence intervals (95% CI) for the association between asthma and PUFA intake, as well as the other study variables, were calculated using logistic regression. The multivariate model included variables associated with both the outcome and exposure (p < 0.20). A total of 64,904 participants completed the questionnaire, the 24-hour dietary recall, anthropometric measurements, and answered the asthma-related question. After adjustment, asthma remained significantly associated with ALA (OR: 1.05; 95% CI: 1.02–1.09) and EPA (OR: 0.61; 95% CI: 0.39–0.95), with the former showing a positive association and the latter a negative one. In conclusion, ALA consumption was positively associated with asthma, while EPA appeared to have a protective effect against asthma among Brazilian adolescents.