Grapefruit Is One of the Weirdest Fruits on the Planet
From its name, to its hazy origins, to its drug interactions, there’s a lot going on beneath that thick rind.
In 1989, David Bailey, a researcher in the field of clinical pharmacology (the study of how drugs affect humans), accidentally stumbled on perhaps the biggest discovery of his career, in his lab in London, Ontario. Follow-up testing confirmed his findings, and today there is not really any doubt that he was correct. “The hard part about it was that most people didn’t believe our data, because it was so unexpected,” he says. “A food had never been shown to produce a drug interaction like this, as large as this, ever.”
That food was grapefruit, a seemingly ordinary fruit that is, in truth, anything but ordinary. Right from the moment of its discovery, the grapefruit has been a true oddball. Its journey started in a place where it didn’t belong, and ended up in a lab in a place where it doesn’t grow. Hell, even the name doesn’t make any sense.
The citrus family of fruits is native to the warmer and more humid parts of Asia. The current theory is that somewhere around five or six million years ago, one parent of all citrus varieties splintered into separate species, probably due to some change in climate.
Three citrus fruits spread widely: the citron, the pomelo, and the mandarin. Several others scattered around Asia and the South Pacific, including the caviar-like Australian finger lime, but those three citrus species are by far the most important to our story.
With the exception of those weirdos like the finger lime, all other citrus fruits are derived from natural and, before long, artificial crossbreeding, and then crossbreeding the crossbreeds, and so on, of those three fruits. Mix certain pomelos and certain mandarins and you get a sour orange. Cross that sour orange with a citron and you get a lemon. It’s a little bit like blending and reblending primary colors. Grapefruit is a mix between the pomelo—a base fruit—and a sweet orange, which itself is a hybrid of pomelo and mandarin.
Because those base fruits are all native to Asia, the vast majority of hybrid citrus fruits are also from Asia. Grapefruit, however, is not. In fact, the grapefruit was first found a world away, in Barbados, probably in the mid-1600s. The early days of the grapefruit are plagued by mystery. Citrus trees had been planted casually by Europeans all over the West Indies, with hybrids springing up all over the place, and very little documentation of who planted what, and which mixed with which.
Citrus, see, naturally hybridizes when two varieties are planted near each other. Careful growers, even back in the 1600s, used tactics like spacing and grafting (in which part of one tree is attached to the rootstock of another) to avoid hybridizing. In the West Indies, at the time, nobody bothered. They just planted stuff.
Sometimes it didn’t work very well. Many citrus varieties, due to being excessively inbred, don’t even create a fruiting tree when grown from seed. But other times, random chance could result in something special. The grapefruit is, probably, one of these. The word “probably” is warranted there, because none of the history of the grapefruit is especially clear. Part of the problem is that the word “grapefruit” wasn’t even recorded, at least not in any surviving documents, until the 1830s.