On a cold December day in Norwich, England, Cathie Martin met me at a laboratory inside the John Innes Centre, where she works. A plant biologist, Martin has spent almost two decades studying tomatoes, and I had traveled to see her because of a particular one she created: a lustrous, dark purple variety that is unusually high in antioxidants, with twice the amount found in blueberries.
At 66, Martin has silver-white hair, a strong chin and sharp eyes that give her a slightly elfin look. Her office, a tiny cubby just off the lab, is so packed with binders and piles of paper that Martin has to stand when typing on her computer keyboard, which sits surrounded by a heap of papers like a rock that has sunk to the bottom of a snowdrift. “It’s an absolute disaster,” Martin said, looking around fondly. “I’m told that the security guards bring people round on the tour.” On the desk, there’s a drinks coaster with a picture of an attractive 1950s housewife that reads, “You say tomato, I say [expletive] you.”
Martin has long been interested in how plants produce beneficial nutrients. The purple tomato is the first she designed to have more anthocyanin, a naturally occurring anti-inflammatory compound. “All higher plants have a mechanism for making anthocyanins,” Martin explained when we met. “A tomato plant makes them as well, in the leaves. We just put in a switch that turns on anthocyanin production in the fruit.” Martin noted that while there are other tomato varieties that look purple, they have anthocyanins only in the skin, so the health benefits are slight. “People say, Oh, there are purple tomatoes already,” Martin said. “But they don’t have these kind of levels.”