EDITOR—Wisborg et al's article raises more issues than it settles.1 Firstly, coffee contains not only caffeine but a mixture of different ingredients (milk, sugar, stabilisers, flavour, and other alkaloids from coffee beans). Attributing the result of drinking coffee to just one constituent seems illogical. If Wisborg et al want to prove what they contend, they should contrast the group taking eight cups of ordinary coffee to those taking eight cups …