Logging downstream/upstream request/response body in Access Logs


I`m trying to find out if its possible to modify the Access Log format to log the downstream/upstream request and response bytes(body) as part of the access log which gets generated for each transaction.
I went through this documentation for the same:

I only see BYTES_SENT which does not give information about upstream/downstream.
Is it possible to modify the access log format to log the downstream/upstream request/response body and headers also if required?