Higher Omega-3 Index Is Associated with Better Asthma Control

by | Feb 17, 2020 | 2020, Asthma, Lung Health, Omega - 3

Written by Angeline A. De Leon, Staff Writer. This study demonstrates that a higher Omega 3 Index is associated with better asthma control and with lower inhaled corticosteroid medication dose, suggesting that a higher erythrocyte n-3 PUFA level may have a role in asthma management.

lung health - asthmaAsthma affects almost 350 million people worldwide  1. Chronic inflammation is a major hallmark of asthma, with asthma patients showing higher circulating levels of C-reactive protein (CRP, blood marker of inflammation), along with more severe airway inflammation 2,3. Adoption of healthier dietary patterns, such as the Mediterranean diet consisting of high fish, fruit, and vegetable intake, has shown protective effects against asthma, reducing severity of asthma symptoms and frequency of attacks 4. Some researchers hypothesize that the Mediterranean style diet’s efficacy in mitigating asthma symptoms may be related to its incorporation of omega-3 polyunsaturated fatty acids (n-3 PUFA), which are known for their anti-inflammatory effects 5. In research models of asthma, higher intake of docosahexaenoic acid (DHA, an n-3 PUFA) is linked to improved lung function and downregulation of interleukins (inflammatory cytokines) 6,7.  In human trials, findings remain mixed, with meta-analyses indicating that there are neither significant benefits nor risks associated with n-3 PUFA in asthma patients 8,9. Thus, in a 2020 study 10 published in Nutrients, investigators sought to determine the association between omega-3 index (O3I, representative of long-term n-3 PUFA status) and clinical asthma outcomes.

A total of 255 subjects with confirmed asthma (mean age = 57.1 years) and 137 without asthma (mean age = 53.5 years) were enrolled in a cross-sectional study in which they underwent a series of pulmonary function tests (forced expiratory volume in one second and forced vital capacity). Asthma patients completed the Juniper Asthma Control Questionnaire (ACQ6) and provided fasting venous blood samples, which were analyzed for plasma inflammatory markers (CRP; interleukin-6, IL-6; and tumor necrosis factor-α, TNF-α). Total fatty acids were also determined from erythrocyte (red blood cell) membranes using gas chromatography, and O3I was calculated as % eicosapentaenoic acid (EPA) + % DHA.

Although no significant differences in O3I were apparent between asthmatic and non-asthmatic subjects (p = 0.089), subjects with well controlled or partially controlled asthma showed a higher O31 score than subjects with uncontrolled asthma (6.0% vs. 5.6%, p = 0.033). No significant differences in lung function or asthma severity were found between subjects with higher vs. lower O3I score (≥ 8% vs. < 8%). However, subjects with higher O3I had a significantly lower maintenance dose of inhaled corticosteroids than those with a lower O3I (p = 0.019).

The first trial to look at O3I in relation to asthma control, the current study provides initial evidence to suggest that higher levels of n-3 PUFA may be linked to better asthma management in adults with persistent asthma. Participants with higher O3I scores used lower doses of inhaled corticosteroid medication and tended to have better controlled asthma. Additional exploratory analyses also revealed that higher O3I was also associated with lower medication doses and decreased levels of CRP in obese subjects. Findings are in line with previous evidence from cross-sectional research suggesting a positive relationship between DHA and EPA levels and asthma control 11. Researchers conclude that supplementation with n-3 PUFA may serve as a helpful adjunct treatment for asthma, however, intervention studies are needed to confirm findings. Key limitations of the current study involve the failure to match asthmatic and non-asthmatic subjects for sex and body mass index (BMI) and the enrollment of a relatively older cohort, which limits generalizability to younger populations. Dietary intake of fish and fish oil supplementation were also not recorded in the current trial.

Source: Stoodley I, Garg M, Scott H, et al. Higher omega-3 index is associated with better asthma control and lower medication dose: a cross-sectional study. Nutrients. 2020; 12: 74. DOI: 10.3390/nu12010074.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Click here to read the full text study.

Posted February 17, 2020.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.
 

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