An Apple A Day or A Bad Apple?

I was recently listening to an episode of This American Life titled, "Ruining It For The Rest of Us" where they featured stories about how easily one person's behavior can have a contaminating effect on others. One particularly haunting story covered the research of Will Felps, a professor at Rotterdam School of Management in the Netherlands, who placed a confederate in a group and observed the impact that this "bad apple" had on the rest of the group. In nearly every case the influence of even one spoiler tarnished the productivity and the morale of the group.
One thing that the researchers in Phelp's study didn't look at, however, is that poor health can impact mood. Could an apple a day and a brief jaunt outdoors help the bad apple get his mood back on track? Or could workplace health and wellness be a protective means of coping for those who might otherwise be affected by a bad apple?

How do health and mood interact in your workplace? Have you seen an instance where a bad apple lowered the productivity of a work group and subsequently led to more sick days or a reluctance of team members to show up for work?