Caffeine can trigger or exacerbate heart rhythm problems. For me mostly ectopic beats, which people feel as skipped beats. Annoying my whole life, until I finally flicked caffeine and the majority went away. Saved myself some pretty major surgery too. A shame the cardiologist didn't mention how much of an affect caffeine can have on one's heart rhythm.
Coffee and caffeine irritate the stomach lining and contribute to poor digestion.
Often the irritation will contribute to IBS and lead to a person's food passing through their digestive system too quickly and causing incomplete digestion.
The full of antioxidants idea is nice, but there is no research that proves antioxidants in the diet are any more than marketing. The antioxidant research was all in dishes and so none of it was actually researched as part of the activity of human cells.
I think it is a great idea to cycle your coffee intake. I went off the stuff completely and after a two week long headache, found I slept better. Less tummy troubles. Less anxiousness about the world, and felt generally calmer. I saved a heap of money by not spending $5 or more a day on coffee.
So I get that a lot of people just can't live without coffee, because I was one of them, and now that I've gone off the stuff I find that my life is actually better without it.
When I do have a coffee, I get all the buzz out of it and my brain speeds up. But I don't do more than a single coffee every two days.
Now, if I have more than a single coffee in a day I am guaranteed to see 3 am.
Good article, even though I don't agree with all of it. We have the World Brain, so we can all do our own research.