The link between diet and respiratory disease has attracted interest in recent years, although available results are often heterogeneous and difficult to translate into clinical practice. In this context, a recent Spanish study published in Respirology offers a noteworthy finding: Greater adherence to the Mediterranean diet appears to be associated with a lower incidence of adult-onset asthma.

The study, conducted within the framework of the SUN project, included 17,127 Spanish adults who had no respiratory disease at enrollment and were followed up for an average of 12.8 years. During that period, 302 new cases of asthma were recorded, and in multivariable analysis, participants with the highest adherence to the Mediterranean diet had a 42% relative reduction in risk compared with those with the lowest adherence. Among elements of the dietary pattern, consumption of fruit, nuts, and fish showed the most consistent inverse associations.

Alicia Padilla-Galo, MD, coordinator of the asthma area of the Spanish Society of Pulmonology and Thoracic Surgery, summed up the main clinical takeaway from the study: “Greater adherence to a healthy dietary pattern, such as the Mediterranean diet, is associated with a lower incidence of adult-onset asthma.” She added an epidemiologically important caveat: “It’s especially relevant because this is a Spanish cohort with prolonged follow-up, in which participants with higher Mediterranean diet adherence showed a relative reduction in asthma risk.”

Although these findings are appealing, they should be interpreted cautiously, given the study design, since this was not a clinical trial. In Padilla’s words, “We should be prudent. This is an association, not proof of causation.” The expert also noted important study limitations: self-reported asthma diagnosis, lack of objective pulmonary function measures, possible residual confounding, and limited capacity to extrapolate the results to other populations. “We should not turn this single study into a specific and definitive primary prevention recommendation for asthma,” she emphasized.

Still, the study has biological plausibility. The Mediterranean diet combines antioxidants, healthy fats, and bioactive compounds with potential anti-inflammatory effects. As Padilla noted, these elements “could modulate inflammation and oxidative stress — two processes central to the biology of asthma.” In that sense, the observed association with fish and with fruit or nuts is consistent with prior mechanistic hypotheses.

The study also suggests the protective association may be stronger starting at age 35, although subgroup analyses of this kind always require caution. Perhaps the more interesting takeaway is the broader idea: Prevention of adult asthma likely does not depend on a single food or isolated intervention but on broader lifestyle patterns.

That is where this work is particularly useful — not so much to establish specific recommendations, but to open the way toward a more integral view of health. For Padilla, the study’s conclusions “reinforce interest in diet as part of a comprehensive respiratory prevention strategy,” although she reminds readers that “we still need more evidence.”

From a practical standpoint, the message is reasonable. “In the consultations, it is worthwhile to include nutrition in conversations about prevention and respiratory health,” the expert said. Not as a substitute for measures with stronger evidence but as part of a comprehensive approach that includes smoking cessation, exercise, healthy weight, and reduction of harmful exposures. In that framework, she concluded, “promoting a Mediterranean dietary pattern is reasonable and clinically sensible — not because we can promise it will prevent asthma but because it likely helps create a less inflammatory biological milieu that is favorable for respiratory and overall health. That is probably the real value of this work.”

This story was translated from Univadis Spain, part of the Medscape Professional Network.