:::Yeah, the misunderstanding was due to my ignorance, not any actual problem with the citation style. 
 :::I don't know if 1983 is too old for this subject, I just was a bit skeptical. The claim the 1976 citation backs up will always be true, whereas the statement the 1983 citation backs up has the potential to become out-of-date. What is once considered quackery or a fad could eventually become a more mainstream diet that is more accepted by the scientific community, like vegetarianism has. I'm not claiming fruitarianism has or ever will (it still seems to be a fringe, potentially dangerous diet), but it gives me pause at least. If the "quackery" conclusion the article puts forth is based on outdated views, it might not be ok to include it here. But this is just hypothetical; probably it's still completely correct. I've requested a copy of the article from my local library (I couldn't get the actual complete journal unfortunately), so hopefully I'll be able to verify it. I doubt I could verify the 1976 source, though, since we don't have the article name or the page numbers. -