In this issue of the European Respiratory Review, YOUNG and HOPKINS [1] elegantly discuss how beans (an important part of the Hispanic diet) could reduce systemic inflammation and, thereby, the risk of chronic obstructive pulmonary disease (COPD) and lung cancer, explaining the risk imbalance between Hispanics, African–Americans and non Hispanic whites. As appropriately acknowledged by the authors, what they propose is a hypothesis, warranting confirmation in specific observational and interventional studies. The purpose of this editorial is to discuss some important issues evoked in their reasoning, focusing on COPD only. Altogether, the main question is: is causal inference between bean intake and reduction in the risk of COPD occurrence possible from available data and, if not, what would be needed to progress,
considering possible confounders?