Output of help() in rmarkdown?

I’d like to include the output of the help() function in my rmarkdown result. Simple case doesn’t work and I’d appreciate any solutions.

# neither of these lead to output in the knitted result
help("c")
help("c", help_type = "text")

# just a little bit of exploration to show that I'm being stymied by the nature of R's help system.
# That's not a complaint, of course. But I hope I can get the result as plain text without resorting
# to direct fs access.
class(help("help"))

## [1] "help_files_with_topic"

as.character(help("help", help_type = "text"))

## [1] "/Library/Frameworks/R.framework/Versions/3.1/Resources/library/utils/help/help"