Most scientists won’t admit it, but some of them are a lot like journalists. Some people in both groups seem to get their jollies and make their reputations by debunking the work of others.

Cinnamon is now important enough for glucose control that the debunkers have jumped on it. A group of five scientists in Maastricht, The Netherlands, carefully studied the effects of cinnamon and found that it doesn’t work.

They found that “Cinnamon supplementation does not improve glycemic control in...