But in all seriousness, of course they can access the data. Otherwise who else would process it to give any health results back? I don't think encryption in transit is relevant to privacy concerns because the concerns are about such data being tied to you at all, in any way. At the same time, yes, this could product valuable health information.
Their better bet would be to allow full anonymity, so even if there is a leak (yeah, the puns write themselves), there is never a connection between this data and your person.