cabbage

I have never much liked cabbage, but Cato, who by all accounts was a sensible guy, thought it was pretty good for you. Here's some of the health benefits he thought you could derive from cabbage:

et hoc amplius lotium conservato eius qui brassicam essitarit, id calfacito, eo hominem demittito, cito sanum facies hac cura (expertum hoc est). item pueros pusillos si laves eo lotio, numquam debiles fient. et quibus oculi parum clari sunt, eo lotio inunguito, plus videbunt. si caput aut cervices dolent, eo lotio caldo lavito, desinent dolere.
De Agri Cultura 157

Heat the urine of a person who eats cabbage habitually, bathe the patient in it. He will be healed quickly (this remedy has been tested). Likewise if you bathe babies in this same urine they will never be sickly, and those with bad eyesight will see better. It also relieves pain in the head or neck.

Personally, I'd rather wear glasses. See here for more of the wonders of cabbage.