You say "tomato" and I say "tomahto." Either way, we're still going to argue about whether it's a fruit or a vegetable -- especially when the issue gets in the craw of my tween daughter.
A couple of days ago, my middle schooler's Phys. Ed. class began a new unit on nutrition. As has been done in the U.S. for generations, her teacher introduced the federally-defined food groups, currently delimited as Vegetables, Fruits, Grains, Dairy and Protein Foods. Her teacher then went on to list tomatoes among the vegetables... which is when the biology professor's kid piped up to argue that this placement of one of the world's beloved fruit crops shows an ignorance of technical definitions.
As if this sort of comment in a seventh-grade gym class wouldn't be enough to put a target on her, my daughter offered one last comment to a growing chorus of dissenting opinion:
"I should know what a fruit is. My dad is a botanist."
Kid, you're only making it harder for yourself.
Upon hearing this story at the dinner table, I found my own self wondering how best to support my daughter's courageous defense of science (Should I email the teacher?) while also encouraging a healthy appreciation for colloquial language, the efficiency of generalization and the art of knowing which battles are worth fighting.
I started by re-examining the food groups, something I hadn't spent much time doing since they were last revised. Designed decades ago to encourage us all to eat a balanced diet consisting of whole foods, the current version of these recommendations went on line in 2010.
Like many Americans alive today, I grew up during a time when foods came from four groups: 1) Fruits/Vegetables, 2) Meats, 3) Milk/Dairy and 4) Cereals/Breads, a scheme that was locked in from 1956-1992.
In 1992, the U.S. Department of Agriculture (USDA) introduced the food guide pyramid, a new system consisting of six groups: 1) Breads/Grains, 2) Vegetables, 3) Fruits, 4) Meat, 5) Dairy and 6) Fats/Oils. In the diagrammatic representation of the pyramid these groups inhabited sections of varying sizes used to reflect how much of each group should be consumed daily, with the grains at the widened base and the fats on the sharpened tip.
The food guide pyramid became MyPyramid in 2005 with a graphic redesign (and new name) fit for modern times. The groups remained the same, but only until 2010 when the ancient image of the pyramid was jettisoned for something even more modern: MyPlate. In a total remake of the brand, the pyramid was replaced with a graphic of a place setting. The main food groups now inhabited new space, with Fruits, Vegetables, Grains and Proteins occupying the plate and Dairy poured into a nearby glass. This was the ideal version of the American diet introduced to my daughter and her classmates on the day she challenged The Man.
So, what about those tomatoes? Where do they find themselves in these new nutritional guidelines? As my daughter found out, the USDA considers them to be vegetables, so this is the food group where they are currently placed. The trouble with this, of course, is that tomatoes are really fruits.
Technically, a fruit is a thing that began as an ovary in a flower. Plant ovaries act like human ones in that they produce egg cells, but they encase their fertilized egg cells inside of seeds that develop as the ovary ripens to maturity. When a plant ovary becomes mature it gets a new name: Fruit.
That means anything with seeds (or just one seed) on the inside of it is, by botanical definition, a fruit. Tomatoes? Fruits. Peppers? Fruits. Avocados? Fruits!
Logically, then, any other plant part we eat that is not a fruit might be considered a vegetable. (Unless the thing you eat is a seed, like a bean; then it's just a seed freed from its fruit.) By this definition, lettuce (leaves), broccoli (flower buds), celery (leaf stalks), carrots (roots), and potatoes (underground stems) would all qualify as vegetables.
So, what gives? Why does the USDA put some fruits -- like tomatoes -- in with the vegetables and let others retain their natural identity?
The first is that "vegetable" has a legal meaning that supersedes, for the purposes of federal nutritional guidelines, the scientific meaning. In 1893, the U.S. Supreme Court ruled (in Nix v. Hedden) that tomatoes would forever be known as vegetables in the eyes of the US government. The justification for this ruling was that the US is able to place tariffs on imported vegetable crops, something that is not true for fruit crops. Pretending that tomatoes are not fruits means we can collect entry fees on them.
The second reason is less Orwellian, perhaps. In the commonly used sense of the word, a fruit is something that tastes sweet. So a watermelon is clearly a fruit, but its close relative, the cucumber, wouldn't be considered as such by most people. The sweet fruits make the USDA list for the fruit group, while the not-so-sweet ones are over in the vegetable camp, wondering where they went wrong.
But there is another twist worth mentioning. According to the Oxford English Dictionary, a vegetable is "a plant or part of a plant used as food." So, really, anything that comes from a plant and is eaten by humans is a vegetable. In other words, all fruits that we eat are both fruits and vegetables if we run with the OED definition.
I am left to wonder if this has just been a decades-long ploy by the USDA to get kids to eat more vegetables by giving a bunch of them a more appealing designation! I wouldn't put this past them. I mean, the grain category is just another bunch of vegetables masked as bagels and corn flakes. And changing the meat group to "Protein Foods" was clearly a coup by Big Vegetable meant to sell more nuts and beans. It's a gosh darn vegetable conspiracy, folks. They want plants all over your plate!
Joking aside, all this is to say that it's probably not worth spending much time arguing about what to call a tomato. There is a scientific definition of fruits, there is a legal definition applied to some crops and there is a colloquial sense for what fruits are. But when I think about the two days of discussion that this whole thing led to with my daughter -- with real-life lessons in biology, economics and politics -- I am just glad that she thought to question things that she was being taught.
And while my inclination as her father is to advise her to consider that she watch how often she does such things in class, I know better than to do this. The last thing any 12-year-old girl needs is to be told to stop asking questions.
So here's to the tomato, the Martine family's favorite fruit.
Follow Dr. Chris Martine on Twitter: www.twitter.com/MartineBotany