Are canned tomatoes a good source of vitamin C, and how do they compare to fresh?

October 28, 2025 •

4 min read

While some vitamin C is lost during the initial canning process, studies show that canned tomatoes retain a significant amount of the vitamin, and their sealed environment helps preserve it longer than in fresh produce stored over time. Thus, the answer to the question "Are canned tomatoes a good source of vitamin C?" is a nuanced but positive one, especially when considering year-round availability.

Quick Summary

Despite an initial loss during processing, canned tomatoes remain a viable source of vitamin C, which is preserved by the airtight seal. They also offer higher levels of the antioxidant lycopene than their fresh counterparts, providing a convenient and nutritious option for many recipes.

Key Points

Initial vs. Long-Term Vitamin C: Canned tomatoes lose some vitamin C during initial heat processing, but the remaining amount is better preserved over time than in stored fresh tomatoes due to the absence of oxygen.
Lycopene Bioavailability: The canning process significantly increases the bioavailability of lycopene, a powerful antioxidant that is more easily absorbed by the body from cooked and canned tomatoes than from fresh ones.
Balanced Nutritional Profile: While fresh tomatoes may start with more vitamin C, canned tomatoes can have higher levels of minerals like calcium and iron. Combining both provides the most comprehensive nutrient intake.
Mindful Selection: To avoid excess sodium and BPA concerns, opt for "low sodium" or "no salt added" varieties and check for BPA-free can linings.
Convenience and Affordability: Canned tomatoes offer a convenient, affordable, and shelf-stable way to include nutrient-rich tomatoes in your diet year-round, regardless of season.
Maximize Absorption: To enhance lycopene absorption, pair cooked tomato products with a source of healthy fat, such as olive oil.

The Canning Process and Vitamin C

When considering the nutritional content of canned tomatoes, it's essential to understand the canning process and how it affects different nutrients. The heat treatment used to sterilize canned goods, known as blanching, is the primary reason for initial vitamin C loss. Vitamin C, a water-soluble vitamin, is sensitive to heat and can leach into the water used during this step. One study cited by Bastyr University noted that canned tomatoes experienced a 29-33% vitamin C loss compared to fresh tomatoes. This initial reduction might make it seem like canned tomatoes are a poor source, but that's only part of the story.

After the initial processing, the remaining vitamin C is preserved remarkably well. The airtight seal of the can prevents oxidation, which is a significant factor in the degradation of vitamin C in fresh produce. Fresh tomatoes, when stored for a period, will naturally lose vitamin C over time due to exposure to air. In contrast, research has shown that canned goods can retain over 85% of their vitamin C content for up to one year when stored at room temperature. This means that out-of-season, fresh tomatoes that have been shipped and stored for a while may contain less vitamin C than their canned counterparts.

Comparing Canned vs. Fresh Tomatoes

While fresh tomatoes might start with a higher vitamin C concentration, the long-term nutritional profile of canned tomatoes offers several distinct advantages. The heat from cooking and canning not only preserves vitamin C against oxidation but also significantly increases the bioavailability of other key nutrients. The cell walls of tomatoes break down during the heating process, making the antioxidant lycopene much easier for the body to absorb. Lycopene is responsible for the red color in tomatoes and is linked to numerous health benefits, including a reduced risk of heart disease and certain types of cancer. In fact, canned tomatoes and other cooked tomato products can have two to three times more bioavailable lycopene than raw tomatoes.

Beyond lycopene, canned tomatoes are also often a better source of certain minerals. For example, research has indicated that canned tomatoes can have higher levels of calcium and iron compared to their fresh counterparts. This difference can be attributed to the concentration effect of the canning process and potential mineral interactions. However, it is also important to note that fresh tomatoes tend to have higher levels of vitamins A and K, as well as folate. A balanced diet that incorporates both fresh and canned tomatoes offers the most comprehensive nutritional benefits.

Potential Concerns and Solutions

Some people express concerns about canned foods due to potential issues with added sodium or chemicals like bisphenol A (BPA) found in can linings. High sodium intake is linked to elevated blood pressure, so it's wise to choose "low sodium" or "no salt added" canned tomato products to mitigate this risk.

For those concerned about BPA, many brands now offer BPA-free linings, and looking for these products or opting for jarred tomato products can address this issue. Many health experts now state that the benefits of consuming canned tomatoes generally outweigh the potential risks, especially when making mindful choices at the grocery store.

How to Maximize Vitamin C from Tomatoes

To get the best of both worlds—the high initial vitamin C of fresh tomatoes and the long-term benefits of cooked ones—incorporating both into your diet is the optimal strategy. Here are some simple ways to ensure you maximize your intake:

Use fresh tomatoes raw: Add raw, seasonal tomatoes to salads, sandwiches, or salsas. Eating them raw preserves their peak vitamin C content. Consider buying fresh tomatoes during the peak summer growing season.
Embrace cooked tomato products: Use canned tomatoes or homemade cooked tomato sauces for soups, stews, and pastas. Cooking increases lycopene bioavailability while still providing a source of preserved vitamin C.
Consider low-sodium options: When using canned tomatoes, always check the label for "low sodium" or "no salt added" varieties to control your sodium intake.
Pair with healthy fats: Add a source of healthy fat, like olive oil, to cooked tomato dishes. Lycopene is a fat-soluble nutrient, so consuming it with fat enhances absorption.

Comparison Table: Fresh vs. Canned Tomatoes


Feature	Fresh Tomatoes	Canned Tomatoes
Vitamin C Content	Higher initially, but degrades over time with storage.	Lower initially due to heat, but remains stable for long periods due to sealed packaging.
Lycopene Content	Present, but less bioavailable to the body.	Significantly higher bioavailable lycopene due to the cooking process.
Convenience & Shelf Life	Perishable, with a short shelf life.	Shelf-stable for a long time, offering convenience.
Availability	Seasonal, and can be bland/expensive out of season.	Readily available and affordable year-round.
Sodium Content	Very low to none, depending on the variety.	Can be high; choose low-sodium options to control intake.
Consistency	Varies widely, depending on ripeness.	Consistently uniform texture, ideal for sauces and stews.

Conclusion

Ultimately, are canned tomatoes a good source of vitamin C? The answer is yes, though they do experience some initial loss during processing. The crucial factor is their impressive ability to retain the remaining vitamin C over a long shelf life, often making them a more reliable source than aging fresh tomatoes, especially out of season. Furthermore, canned tomatoes provide a superior source of bioavailable lycopene, a potent antioxidant that supports heart health and may reduce cancer risk. For a balanced diet, both fresh and canned tomatoes have their place, offering different nutritional strengths. By selecting low-sodium and BPA-free canned products, consumers can enjoy a convenient, affordable, and nutritious ingredient year-round. The key is understanding how each form delivers its unique nutritional benefits and incorporating them appropriately into your diet.

For more information on the nutritional comparison of fresh, frozen, and canned fruits and vegetables, see the comprehensive study in the Journal of the Science of Food and Agriculture.

Frequently Asked Questions

No, cooking tomatoes does not destroy all the vitamin C. While heat is known to break down water-soluble vitamins like C, a significant portion remains, especially since the canning process seals the product, preventing further oxidation.

Lycopene is significantly more bioavailable and generally higher in canned and other cooked tomato products than in fresh tomatoes. The heat from cooking breaks down the cell walls, making the lycopene easier for your body to absorb.

Some canned tomatoes can be high in sodium, which is added for flavor and preservation. However, you can easily avoid this by choosing "low sodium" or "no salt added" varieties.

For cooked dishes like sauces, stews, and soups, canned tomatoes are often an excellent substitute, offering a consistent flavor and a boost in bioavailable lycopene. For recipes where the raw flavor and texture are key, fresh is still the best choice.

Canned tomatoes have a long shelf life, typically lasting for at least one year. The canning process and sealed container help preserve nutrients, though minor degradation of certain vitamins, like C, can occur over very long storage periods.

Some canned goods traditionally used can linings containing BPA. However, many brands now offer BPA-free options. If this is a concern, look for labels indicating BPA-free packaging or choose glass jars.

Canned tomatoes can be more environmentally friendly in some circumstances, as they reduce food waste by utilizing peak-ripeness tomatoes and providing a shelf-stable option. Fresh tomatoes have a shorter shelf life and are more prone to spoilage.