I lost most of my sense of smell twenty years ago at 16 due to falling down a mountain on a mountain bike. I guess I should be dead, but am still alive and run a 5k five days a week. I do, however, have to take caution around strong smells such as gasoline.
So, as living proof, I can refute their claims, hypotheses, etc. all day. If one is 75 or older, then it may be applicable.
Wrong link there DL but did see the article on the webpage.