Food for the Lungs: The Mediterranean Diet and Adult‐Onset Asthma

The global burden of asthma remains substantial, affecting up to 29% of the population in some regions and imposing significant healthcare and socioeconomic costs [1]. While much research has focused on pharmacological management and environmental triggers, the role of diet in asthma prevention, particularly in adults, has received comparatively less attention. Dietary research in asthma has long focused on individual nutrients, antioxidants or fatty acids, yielding inconsistent and often disappointing results. More recently, attention has shifted toward dietary patterns, which better reflect real-world exposures. The Mediterranean diet (MedDiet), characterised by high consumption of fruits, vegetables, whole grains, legumes, nuts, olive oil and fish, has long been promoted for its cardiovascular and metabolic benefits [2]. Its anti-inflammatory and antioxidant properties are well-documented, making it a plausible candidate for reducing the risk of chronic inflammatory diseases, including asthma [3]. Despite this biological plausibility, clinical evidence for its role in asthma, particularly adult-onset asthma, has been inconsistent. For example, a Lifelines Cohort study found no significant association between overall diet quality and adult-onset asthma [4], while meta-analyses suggest that greater adherence to the MedDiet or fruit- or vegetable-rich diets may reduce the risk of childhood asthma [5, 6]. Evidence for other dietary patterns is also mixed: the Western diet (of processed meats and refined grains, high-fat dairy products and sugary drinks and desserts) shows inconsistent associations with asthma prevalence or development [7]. Higher adherence to the Dietary Approaches to Stop Hypertension (DASH) diet was associated with lower asthma prevalence and wheezing burden in adolescents [8], and reduced inflammatory markers and improved asthma control in adults [9, 10]. Given these inconsistent findings, open questions remain regarding the role of diet and nutrition on asthma prevention and control. In a recent publication in Respirology, Javier Errasti Viader and colleagues [11] provide much needed prospective evidence from the SUN (Seguimiento Universidad de Navarra) cohort that adherence to the Mediterranean diet is associated with a substantially lower risk of adult-onset asthma in a Spanish cohort. Their findings raise an important and under-addressed question: can lifestyle patterns meaningfully contribute to the primary prevention of asthma in adults? Over a median follow-up of 12.8 years, participants with the highest adherence to the MedDiet (Mediterranean Diet Score [MDS] ≥ 7) exhibited a 42% lower risk of developing asthma compared to those with the lowest adherence (MDS ≤ 2). This inverse association persisted after adjustment for confounders such as body mass index (BMI), smoking and chronic diseases and was particularly pronounced in participants aged ≥ 35 years. Among individual dietary components, the protective effect appeared to be driven by higher consumption of fruit/nuts and fish, aligning with mechanistic evidence implicating oxidative stress, lipid mediators, and immune dysregulation in asthma pathogenesis. Omega-3 fatty acids may attenuate pro-inflammatory eicosanoid pathways, while fruit-derived antioxidants may counteract oxidative airway injury [12], mechanisms particularly relevant to adult-onset and obesity-associated asthma phenotypes [13]. While the STRENGTH trial reported negative findings regarding prevention of cardiovascular events through Omega-3 supplementation in statin-treated patients [14], the recent PISCES study shows that supplementation with antioxidants and omega-3 compounds can reduce cardiovascular events with surprisingly high efficacy in high-risk populations, such as individuals receiving maintenance haemodialysis [15]. While the mechanisms of these effects remain to be elucidated, the PISCES study findings support the biological plausibility of beneficial effects of diets rich in Omega-3 fatty acids on inflammation-dominant conditions. Adult-onset asthma differs biologically and clinically from childhood asthma, often presenting with less atopy and greater systemic inflammation [16]. Aging-related immune dysregulation, metabolic dysfunction, and cumulative environmental exposures may increase susceptibility. In this context, the anti-inflammatory and immunomodulatory properties of the MedDiet are biologically plausible modifiers of risk. Notably, the protective association observed in participants aged ≥ 35 years supports the hypothesis that diet may exert greater influence on asthma phenotypes emerging later in life, or that long-term dietary exposures are required before measurable respiratory effects become evident. To build on these findings, the MedDiet's interaction with asthma phenotypes and life-course timing needs to be evaluated further. Collectively, these results align with findings from other studies. Uddenfeldt et al. (2010) reported associations of lower incidence of asthma with a diet rich in fish and fruit in a Swedish cohort [17] while Mendelian analyses found a negative association between fruit consumption and asthma risk [18] These data support the inclusion of dietary counselling to complement, but not replace, pharmacological management and thereby shift asthma management from treatment alone toward prevention and risk reduction, a point further highlighted by the Global Initiative for Asthma (GINA). While GINA acknowledges the limited impact of pharmacological approaches on asthma incidence, current strategies highlight smoking avoidance, occupational exposure control, and obesity prevention; yet guidance on diet remains limited [19]. The SUN cohort findings help to address this gap, reinforcing the GINA-aligned principle that modifiable lifestyle factors matter. Although not sufficient to justify asthma-specific dietary recommendations, the MedDiet represents a low-risk, high-benefit pattern already recommended for cardiovascular and metabolic health, strengthening the argument for its inclusion in holistic respiratory health frameworks. Further studies are needed to build on their findings in diverse populations, including non-Mediterranean regions and lower socioeconomic groups. As asthma heterogeneity was not directly addressed, future research should examine how diet interacts with obesity, physical activity, environmental factors (e.g., air pollution, allergens), and socioeconomic factors to shape asthma risk across adulthood and identify subgroups (severity of asthma, eosinophilic asthma, atopic asthma, et cetera) that may benefit most from dietary interventions. Assessments of long-term adherence to the MedDiet and its impact on asthma severity, control, and quality of life are also critical. In summary, the study by Errasti Viader and colleagues adds to the growing body of evidence supporting the role of diet in respiratory health. Their findings challenge the traditional view that asthma prevention lies largely beyond lifestyle modification and suggest that dietary patterns contribute to reducing adult-onset asthma. As asthma prevalence continues to rise globally, especially in an era where chronic diseases are increasingly linked to modifiable lifestyle factors, integrating dietary and lifestyle strategies into prevention frameworks deserves serious consideration. After all, what we eat matters not just for our hearts and waistlines, but for our lungs as well. The author has nothing to report. The author declares no conflicts of interest.