First, we don't have asthma here. It's a serious condition. I don't know the ins and outs. As with everything on this site, but especially here, use your on best judgement!
Asthma involves an inflammation of the airways, making it hard to breathe. It often has specific triggering events, but if you can figure out and remove the underlying cause, those same events stop triggering attacks. The Food Intolerance Network has observed that food chemicals are a really common underlying cause. It seems to me that if you can process those food chemicals better, that's even better than avoiding the naturally occurring ones.
A couple of the most common food chemical triggers of asthma are sulfites, and salicylates. Molybdenum may help with both of these.
Sulfite builds up when sulfoxidation isn't working properly. It isn't being turned into sulfate like it's supposed to be, and so you can also end up with a deficiency of sulfate. Sulfate is used to detox salicylates, and people sensitive to salicylates tend to be low in sulfate (Waring did the research). Molybdenum deficiency appears to be the common cause of impaired sulfoxidation. It makes sense, then, that a molybdenum deficiency could create a sensitivity to both salicylates and sulfites, setting the perfect stage for asthma.