Nutrition Diet: What vegetable is not a real vegetable?

October 9, 2025 •

4 min read

A 19th-century US Supreme Court case legally defined the tomato as a vegetable for taxation purposes, but botanically, it is a fruit. This historical confusion highlights a key question in nutrition: what vegetable is not a real vegetable? It turns out, many foods we consider veggies are, in fact, fruits in a scientific sense.

Quick Summary

Many foods treated as vegetables in cooking, such as tomatoes, cucumbers, and squash, are technically fruits from a botanical perspective, as they develop from a flower and contain seeds. The distinction hinges on culinary versus scientific classification.

Key Points

The Difference is Scientific, not Culinary: The classification of a food as a fruit or vegetable depends on botanical definitions, not how it's used in cooking.
Botanical Fruit Definition: Any seed-bearing structure that develops from the flower's ovary is a fruit.
Culinary Vegetable Definition: Any savory, non-sweet edible part of a plant (roots, stems, leaves) is considered a vegetable.
Common Fruit-Vegetables: Foods like tomatoes, cucumbers, peppers, eggplants, and squash are all botanically fruits despite their common culinary use.
Nutritional Value Remains Unchanged: The classification doesn't alter a food's nutritional profile, so both botanical fruits and vegetables are vital for a healthy diet.
True Vegetables: Carrots, spinach, broccoli, and onions are examples of foods that are true botanical vegetables.

The Great Culinary-Botanical Divide

For most people, the difference between a fruit and a vegetable seems simple: fruits are sweet, while vegetables are savory. This everyday distinction, however, is purely a culinary one. From a scientific or botanical perspective, the classification is based on the plant's reproductive parts, which leads to some surprising truths about the foods on our plates.

The Scientific Classification

Botanists define a fruit as the mature, seed-bearing ovary of a flowering plant. This seed-bearing structure develops from the flower's ovary. Conversely, a vegetable is a catch-all term for any other edible part of a plant, such as the leaves, roots, stems, bulbs, or flowers. This is the fundamental difference that puts many "vegetables" into a new category.

The Kitchen's Role in Labeling

In the kitchen, usage and taste dictate classification. Ingredients that are typically sweet and used in desserts or as snacks, like apples and strawberries, are called fruits. Ingredients that are savory and commonly cooked into main dishes, like potatoes and onions, are called vegetables. This practical distinction is what leads to the common confusion, exemplified famously by the tomato, which is a botanical fruit but a culinary vegetable.

Common Botanical Fruits Masquerading as Vegetables

A wide variety of common foods are botanically fruits, challenging our everyday perception. Understanding these can add an interesting layer to your knowledge of diet and nutrition.

Tomatoes and Cucumbers

Tomatoes: Perhaps the most famous example, tomatoes contain seeds and develop from a flower, making them a fruit. Their legal status as a vegetable in the US since 1893 was for tariff reasons, not botanical ones.
Cucumbers: These popular salad ingredients are also fruits. They grow from the flower of the cucumber plant and are filled with seeds, placing them squarely in the botanical fruit category.

The Squash Family

All types of squash, including zucchini, pumpkins, and butternut squash, are botanically fruits. Like tomatoes, they develop from the plant's flower and contain seeds, and belong to the Cucurbitaceae family, along with other gourds.

Peppers and Eggplants

Both sweet and hot peppers, along with eggplants, are botanical berries—a specific type of fruit. They are members of the nightshade family, and you can see their seeds when you cut them open. Culinarily, however, they are almost always used in savory dishes.

Beans and Peas

While the individual peas and beans are seeds, the pods they grow in are the mature ovaries of the plant, meaning the entire pod is a fruit. Green beans, for example, are seed-bearing pods and therefore botanically fruits, despite their name.

What Constitutes a True Vegetable?

So, if many "vegetables" are fruits, what are true vegetables? True botanical vegetables come from other parts of the plant. Examples include:

Roots: Carrots, radishes, sweet potatoes, and turnips.
Stems: Asparagus and celery.
Leaves: Spinach, lettuce, kale, and cabbage.
Bulbs: Onions and garlic.
Flowers: Broccoli and cauliflower.

Understanding Botanical vs. Culinary Classification


Feature	Botanical Classification	Culinary Classification
Definition	A seed-bearing part of a flowering plant that develops from the ovary.	Any edible part of a plant that is typically savory and used in main courses.
Basis	Scientific structure and reproductive function.	Taste profile and common usage in meal preparation.
Examples	Tomatoes, cucumbers, zucchini, pumpkins, peppers, avocados.	Carrots, potatoes, spinach, lettuce, celery, broccoli.

Nutritional Implications and Dietary Benefits

The botanical classification of a food does not change its nutritional value. Regardless of whether a tomato is a fruit or a vegetable, it remains a fantastic source of vitamin C and antioxidants like lycopene. Similarly, avocados, botanically large berries, are rich in healthy fats. A balanced nutrition diet should include a wide variety of plant-based foods, regardless of how they are categorized.

Eating a diet rich in fruits (botanical and culinary) and vegetables offers numerous health benefits, including weight management, reduced inflammation, and a lower risk of chronic diseases. The high fiber content in plant-based foods supports digestive health and can help regulate blood sugar. A diverse intake ensures you get a wide spectrum of vitamins, minerals, and phytonutrients.

Conclusion: Does the Label Matter?

Ultimately, the distinction between a fruit and a vegetable is more a matter of intellectual curiosity than nutritional significance. For a well-rounded diet, both categories are essential. The next time you add tomatoes to a savory dish or debate whether a cucumber belongs in a fruit salad, remember that the true value of these foods lies in their nutritional contribution, not their botanical name. A diverse, plant-rich diet is the healthiest approach, no matter how you categorize your ingredients.

For more information on the history of this debate, a helpful resource can be found at the University of Maine Cooperative Extension.

Frequently Asked Questions

The simplest way to tell if a food is a botanical fruit is to check if it contains seeds and developed from the flower of the plant.

From a botanical perspective, a tomato is a fruit because it grows from a flower and contains seeds. Culinarily, it is considered a vegetable due to its savory flavor and use in main dishes.

Yes, both peppers and cucumbers are botanically fruits. They are seed-bearing structures that develop from the flowers of their respective plants.

True botanical vegetables include roots (carrots), stems (asparagus), leaves (spinach), and flowers (broccoli).

No, the classification does not change a food's nutritional value. A balanced diet should include a variety of plant-based foods, regardless of how they are categorized.

We call some botanical fruits 'vegetables' because of culinary traditions. They are typically used in savory dishes and not as desserts, leading to their common classification as vegetables.

The botanical classification is based on the plant's reproductive parts (fruit = seed-bearing ovary), while the culinary classification is based on taste and usage (fruit = sweet, vegetable = savory).