The National Institute for Japanese Language has made a list of 33 Japanese terms as replacements for 33 katakana loanwords "mostly English" that are used in government documents and by the media, but that are difficult to understood by the public.
I guess the most interesting part of this discussion is the question, "What is Japanese and what isn't," or "What is English and what isn't"? All I can say about loan words in Japanese is that they are often difficult to understand, and it slows reading considerably. When I run into a word written in katakana, I have to sound it out and try to link it up with the word it is meant to represent in another language. It is also interesting that the article says that most of the loanwords are English, because they resemble English so little. For example, one word that comes up in the article is "dei saabisu". It is supposed to represent "day service." I don't think it resembles the English very closely in spelling or in pronunciation, and I don't think there is an equivilant concept in English. Day service is the care of elderly people during the day at their home or in a facility and then letting them be with their families at night.
Here's the article.