When we say pickles, we often mean pickled cucumbers. But any number of vegetables (or meat, or eggs) can be preserved in a solution of vinegar or salt brine. While the process of pickling foods goes back into antiquity, it became very handy for sailors during the Age of Exploration.
Scottish doctor James Lind discussed how pickles could fight scurvy, noting how the “Dutch sailors are much less liable to the scurvy than the English, owing to this pickled vegetable carried out to sea.” The pickled vegetable in question was cabbage. And Captain James Cook was such a proponent of what he called Sour Krout that he gave his officers as much as they wanted, knowing that the crew would eat it as soon as they saw the officers liked it.
But not everyone was a fan. John Harvey Kellogg, who as we’ve previously discussed was deeply concerned about eating food with any known flavor, felt pickles were one of the "stimulating foods" that needed to be avoided.
The history of pickles is full of anecdotes like this, which you can see, or watch in a video, at Mental Floss.