Lectins in Tomatoes: How to Enjoy Tomatoes on a Lectin-Free Diet

Tomatoes may contain lectins, but following a lectin-free or low-lectin diet doesn’t necessarily mean you have to give them up. In this guide, we’ll look at lectins in tomatoes, why some people choose to reduce them, and how preparation methods such as peeling, deseeding, and pressure cooking can help. I’ll also share the tomato products I use and some of my favorite ways to enjoy tomatoes on a lectin-free diet.

Do tomatoes have lectins?

Yes, tomatoes contain lectins. Lectins are carbohydrate-binding proteins found throughout the plant kingdom, including in legumes, beans, whole grains, seeds, fruits, and vegetables. Tomatoes belong to the nightshade family (Solanaceae), along with potatoes, peppers, and eggplants.

Lectins perform important functions in plants, including roles related to growth and defense against predators. Because they bind to carbohydrates—and some to sialic acid—they are sometimes referred to as “sticky proteins.”

Certain dietary lectins have received attention because they can resist digestion and interact with cells lining the gastrointestinal tract. One area of interest is their potential effect on the intestinal barrier and increased intestinal permeability, commonly referred to as “leaky gut.”

The relationship between dietary lectins and human health has been discussed in the scientific literature for decades. A frequently cited article, “Do dietary lectins cause disease?” published in The British Medical Journal, explored possible connections between dietary lectins and conditions including coeliac disease, peptic ulcers, and rheumatoid arthritis.

Dr. Steven Gundry, former heart surgeon and author of The Plant Paradox, later brought the conversation about dietary lectins to a much wider audience. His approach focuses on how certain lectins may contribute to increased intestinal permeability and other health problems in susceptible individuals. Importantly, The Plant Paradox isn’t simply about permanently eliminating every food that contains lectins. Gundry also recommends traditional and modern preparation methods—including peeling and deseeding, soaking, fermenting, and pressure cooking—to reduce lectins in certain foods.

Different lectins behave differently, and the food source, quantity, preparation method, and individual susceptibility all matter. This is why a lectin-free or low-lectin approach doesn’t always mean permanently eliminating every lectin-containing food.

Tomatoes are a good example. For those following a lectin-free diet, removing the skin and seeds and using appropriate cooking methods can make it possible to enjoy tomatoes without treating them as an all-or-nothing food.

For a broader look at this topic, see my guide on how to reduce lectins in your favorite foods.

You can’t conceive of your diet without tomatoes? I hear you!

Several years ago, if you had asked me which food I could eat for the rest of my life without getting bored, I would have said tomatoes and cheese. I used to hear about people who didn’t like tomatoes and thought they were weirdos (sorry if you are one of them!).

I ate tomatoes in various forms at almost every meal: a fresh tomato for breakfast, cherry tomatoes in my lunch salad, and often a tomato-based sauce for dinner.

Growing up on a farm, with vine-ripened tomatoes throughout the summer, I knew that the out-of-season tomatoes I bought from supermarkets were nothing like the tomatoes I grew up with. I would still eat them, even though they were rubbery and tasteless.

Even as a child, I remember hearing people say that removing the seeds from certain vegetables and fruits made them easier to digest.

About ten years ago, while eating my usual lunch salad in the office kitchen, I complained to a colleague that my heartburn was getting worse. She looked at my plate and suggested the tomatoes might be contributing to it. She even mentioned that removing the seeds could make a difference.

Well, guess what? I didn’t do anything.

Eventually, my heartburn became so uncomfortable that I couldn’t sleep without taking an antacid. Around that time, I came across the concept of dietary lectins, and something clicked. I was ready to give up anything if it meant getting rid of that nasty acid reflux.

Removing tomatoes from my diet, at least temporarily, wasn’t the complete answer, but it became part of a much bigger story for me about lectins, food preparation, and digestive health.

How to reduce lectins in tomatoes

Here is the good news: if you love tomatoes, you don’t necessarily have to give them up for good.

The initial stages of some lectin-free protocols are more restrictive, allowing the gut time to heal before certain foods are gradually reintroduced in properly prepared forms. How much you eventually tolerate is individual.

Here are the methods I use to reduce lectins in tomatoes.

1. Remove the skin and seeds

Peeling and deseeding tomatoes is one of the simplest ways to reduce the lectins we are trying to avoid when following a lectin-free diet.

You can easily peel tomatoes by blanching them: make a small X-shaped incision on the bottom, immerse them in boiling water for about a minute, then transfer them to cold water. The skin should slip right off. After that, cut the tomatoes open and scoop out the seeds.

When I use tomatoes for salads, cold platters, or sandwiches, I prefer not to blanch them. Instead, I remove the skin with a vegetable peeler. With some varieties of ripe tomatoes, the skin comes off easily with a small paring knife.

If you’re a kitchen geek like me, you might want to check out this tomato knife, which is perfect for slicing delicate tomatoes or berries as well as thick-skinned fruits such as citrus or avocados. I bought mine years ago because I loved tomatoes so much.

2. Pressure-cook tomatoes

Cooking can reduce the activity of many lectins, and pressure cooking is one of the methods used in The Plant Paradox approach for reducing lectins in foods such as legumes, tomatoes, and other nightshades.

When preparing soups, sauces, or stews with tomatoes, consider using a pressure cooker. You can use whole tomatoes when pressure-cooking them, although I personally prefer to remove the seeds anyway.

3. Use tomato passata for tomato-based sauces

When making a lectin-free homemade pizza, pasta sauce, or ketchup, I use store-bought tomato passata, imported from Italy, and with a clean ingredient list—ideally just tomatoes, or tomatoes and salt.

Tomato passata is a smooth tomato purée strained of skins and seeds, making it a convenient option for tomato-based sauces when following a lectin-free diet.

4. Use good-quality tomato paste

Tomato paste is another convenient way to add concentrated tomato flavor to sauces, soups, and stews. I always choose a good-quality tomato paste made without the skins and seeds and with no questionable added ingredients.

Ways to enjoy tomatoes on a lectin-free diet

If you follow a low-lectin or lectin-free diet, there are still plenty of ways to enjoy tomatoes:

• Make a pizza sauce using tomato passata
• Make ketchup using tomato passata
• Add peeled and deseeded tomatoes to salads and platters
• If you eat dairy products, try a Caprese salad with buffalo mozzarella or burrata, basil, extra virgin olive oil, flake salt, and peeled and deseeded heirloom tomatoes.
• Try our Tomato Feta Salad with Microgreens
• Make a tomato salsa with peeled and deseeded tomatoes
• Make bruschettas using peeled and deseeded tomatoes
• Add peeled and deseeded tomatoes to stews and sauces
• Add tomatoes, tomato paste, or tomato passata to pressure-cooked sauces, stews, and soups

Beyond lectins: quantity, seasonality, and individual tolerance

Over the years, I’ve become more mindful not only of how I prepare tomatoes, but also of how much and how often I eat them. Today, tomatoes are available year-round and can easily find their way into every meal. Growing up on a farm, that wasn’t the case. Fresh tomatoes were a seasonal food, enjoyed ripe from the garden during summer.

I’ve also learned that quantity matters for me. I can enjoy a little peeled and deseeded tomato sauce on pizza or some tomato in a stew, but tomato-heavy sauces and raw tomatoes don’t make my stomach particularly happy.

Interestingly, traditional food systems also have their own perspectives on tomatoes and digestion. Modern Ayurvedic dietary practice generally considers tomatoes sour and heating and often recommends moderation in certain Pitta-related digestive patterns. Traditional Chinese Medicine takes an almost opposite energetic view, generally classifying tomatoes as cooling and sweet-sour, and may recommend limiting them when digestion is considered weak or “cold.”

These traditions explain tomatoes very differently and aren’t explanations of lectins. But I find the broader principle interesting: food isn’t always black and white. Season, preparation, quantity, and individual tolerance all matter.

How to pick the best tomatoes

Not all tomatoes are created equal. For me, the only fresh tomatoes worth eating are organic, vine-ripened, and locally sourced from a farmers’ market or my own garden. That also means eating fresh tomatoes mainly when they’re in season. In the Northern Hemisphere, that’s generally during summer and early fall, depending on where you live.

For packaged tomato products, I choose high-quality organic products, usually made in Italy or by trusted local producers. I always choose products made without the skins and seeds and with a simple, clean ingredient list.

Those perfectly round, red, shiny tomatoes found in supermarkets are often rubbery and tasteless. Commercial tomatoes may be harvested while still green and firm so they can withstand transportation, then exposed to ethylene—a natural plant hormone involved in ripening—to trigger the ripening process.

They may turn red, but color alone doesn’t create the flavor of a tomato allowed to ripen naturally on the vine. And if I’m going to eat tomatoes, I want them to actually taste like tomatoes.

Conclusion on lectins in tomatoes

There is nothing like a beautiful, juicy, sweet tomato ripened on the vine. It may not look perfect and might come in yellow, orange, pink, striped, or any shade of red.

If you’re concerned about lectins in tomatoes, you don’t necessarily have to choose between eating tomatoes freely and avoiding them forever. Removing the skins and seeds, pressure-cooking tomatoes, and choosing products such as passata and good-quality tomato paste are practical ways to enjoy tomatoes on a lectin-free diet.

For me, quality, seasonality, quantity, and individual tolerance matter too. I’d much rather enjoy a truly delicious tomato, prepared in a way that works for me, than eat tasteless tomatoes at every meal, all year round.

Printable Lectin-Free Food List

If you’d like a practical reference while shopping, I created a printable Plant Paradox Shopping List organized according to Dr. Gundry’s food pyramid, with lectin-free foods clearly grouped by category. You can download the shopping list for free here.

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