If you will create one doorway to all your related sites, and submit that ONLY, then ... you'll be much less likely to suffer the penalties from which spectregunner is trying to protect you.
And you'll have one place that is more useful simply because it is more informative, if only because it provides a more coherent picture of ALL the sites' authoritativeness.
And not only is THAT critical to people looking for information about their health, but it is an important part of an editor's responsibility to evaluate it with a view towards determining whether a site is listed at all (ESPECIALLY in the area of health.)
On the one hand -- a growing record as a maliciously deceptive spammer. On the other -- a complete picture of one's core competencies. It never ceases to amaze me how many people are deathly afraid of the latter possibility. Of course, that comes close to telling us all we need to know about whether to list any of the sites.
So: what are YOU most afraid of?