The Tomato Looks Like A Heart. That's Not Why It Helps.

You've seen the picture. A tomato cut across, set next to a drawing of a heart. Both red, both round, both split into chambers.

It gets passed around as proof that nature labels its food. Eat the thing that looks like the organ, and that organ gets stronger.

Here's the honest version. A tomato does nothing for your heart because of its shape. But there are real reasons to eat more of them, and one of them depends on how you cook them...

The shape idea has a name. It's called the Doctrine of Signatures, and it is very old.

The Swiss doctor Paracelsus pushed it in the 1500s. A German writer named Jakob Böhme gave it a whole book in 1621, called Signatura Rerum. An English writer, William Coles, wrote that walnuts "have the perfect signatures of the head."

So where does the tomato fit? Not where you'd think.

When the tomato reached Italy from the Americas, a doctor named Pietro Andrea Mattioli wrote it up in 1544. He said the ripe fruit was golden. By 1554 he was calling it pomi d'oro, the golden apple. Italians still call it that today.

And the oldest tomato "signature" I could find points the other way. In April 1909, a London medical weekly called The Hospital ran a piece on the doctrine. It noted that a cut tomato looks like a slice of a tumor, "and so the one was rumoured to be the cause of the other."

Two verdicts, one fruit, and the same shaky logic behind both.

The Chambers Don't Even Match

Your heart has four chambers. A tomato's chambers are where the seeds sit, and the count changes from one kind to the next.

Cherry tomatoes usually have two. Most big slicing tomatoes have four or five. Some have ten or more.

So the match is luck, not design. Drop the shape story. Keep the tomato, though, because the reasons to eat it are real...

What The Red Actually Does

The red in a ripe tomato comes from a pigment called lycopene. Call it the red pigment from here on.

In 2017, a team at Northumbria, in England, led by Ho Ming Cheng, pooled 21 trials. Some fed people tomato foods. Others gave red pigment pills.

People eating more tomato saw their bad cholesterol drop a little. Their arteries also opened wider on cue, a sign of healthy blood vessels.

The pills did something too. They trimmed the top blood pressure number by about 5.7 points. But most of those trials were small and short, so hold that loosely.

The Part Nobody Puts In The Picture

Tomatoes also carry potassium. One hundred grams of fresh tomato has about 237 milligrams, by the U.S. Department of Agriculture's count. The same weight of tomato paste has over 1,000.

Why does that matter? Potassium helps your body push out salt, and salt drives blood pressure up.

A 2013 review in the BMJ pooled 22 trials. More potassium lowered the top number by about 3.5 points. That effect showed up in people who already had high blood pressure, not in people who didn't.

Then there's the bigger picture. A Barcelona team tracked 7,056 older Spaniards in the PREDIMED study and reported in 2024. People eating the most tomato, over 110 grams a day, had a 36% lower risk of developing high blood pressure.

That is a look at diets, not a test. It shows a link, not proof. And the Women's Health Study, published by Howard Sesso's team in 2003, found something telling. Among 39,876 women, those eating 7 to 10 servings of tomato foods a week had less heart disease. But the amount of red pigment on its own showed no clear link.

The food beat the compound. That fits everything else this newsletter keeps finding.

Is Cooked Really Better?

You've heard that cooked tomatoes are better for you. For the red pigment, the evidence says yes.

In 2002, Rui Hai Liu's lab at Cornell heated tomatoes to 190 degrees. After 30 minutes, the red pigment they could measure had jumped by about 165%. Vitamin C fell by 29%.

Processed beats fresh, too. In 1997, Helmut Sies and his team in Düsseldorf gave five people the same dose of red pigment two ways. One meal was 400 grams of fresh tomato. The other was 40 grams of tomato paste. Both came with oil.

The paste gave about 3.8 times more red pigment in the blood over the hours that followed. Five people is tiny. But it matches their earlier 1992 test, where boiled tomato juice raised blood levels and raw juice did not.

Fat is the other half. At Ohio State in 2005, Nuray Unlu's team added avocado to salsa. Eleven people absorbed 4.4 times more red pigment than from salsa with no avocado.

Here's what I'd want you to know, though. Higher blood levels are not the same as a healthier heart. I couldn't find a single trial pitting cooked tomatoes against raw ones for heart attacks. And raw keeps more vitamin C. So eat both...

The Ten-Minute Pan

This is the simplest way to put the cooking science on your plate.

You need: 2 tablespoons olive oil, 2 cloves garlic, 1 tablespoon tomato paste with no salt added, one 14.5-ounce can of diced tomatoes with no salt added, a pinch of salt, and a few basil leaves.

Do this: Warm the oil over medium heat. Add the sliced garlic for a minute. Stir in the paste and let it darken for a minute more. Add the tomatoes and simmer for 15 minutes. Tear in the basil at the end.

Spoon it over beans, eggs, fish or pasta. It keeps four days in the fridge.

Three Things Worth Knowing At The Store

The picture of the tomato and the heart will keep going around. It's a nice picture. It just isn't evidence.

What does hold up is plainer. Tomatoes bring potassium, a red pigment your body takes in best when cooked with fat, and a food link to lower blood pressure that keeps showing up in long studies.

Open a can of tomatoes this week. Cook them in olive oil, and eat them twice.

Stay well,
The Healing Plate