Has allergenic pollen an impact on non-allergic diseases?

Recent observations suggest that pollen do not only interacts with the human immune system to elicit an allergic response in susceptible individuals. It would have a much broader impact on human health. This applies more especially, yet not exclusively, to three groups of diseases: non-allergic respiratory conditions, cardio- and cerebrovascular accidents, and psychiatric disorders including suicide and suicide attempt. At present, the reasons for these unexpected connections are only hypothetical, and require further exploration in larger samples, but there is perhaps a multitude of them. One must therefore favour a holistic approach of pollen and its impact on human health.