Does Cooking Tomatoes Destroy Vitamin C? The Surprising Truth

November 14, 2025 •

3 min read

According to a study by Cornell University researchers, heat processing can reduce vitamin C in tomatoes, but it significantly enhances other beneficial nutrients like lycopene. This reveals the complex answer to the question: does cooking tomatoes destroy vitamin C?

Quick Summary

Cooking tomatoes causes vitamin C loss, but simultaneously boosts the bioavailability of the powerful antioxidant lycopene, offering a different set of health advantages.

Key Points

Vitamin C is Reduced: Cooking, especially with high heat and water, degrades the heat-sensitive vitamin C in tomatoes due to leaching and temperature.
Lycopene is Enhanced: Heat breaks down the thick cell walls of tomatoes, significantly increasing the bioavailability and absorption of the antioxidant lycopene.
Nutritional Trade-off: The cooking process involves a nutritional trade-off, where a loss of vitamin C is compensated by a notable gain in absorbable lycopene.
Cooking Method Matters: Quick cooking methods like steaming or microwaving retain more vitamin C than boiling, which causes significant loss.
Eat Both Raw and Cooked: For a full spectrum of benefits, consume both raw tomatoes for maximum vitamin C and cooked tomatoes for maximum lycopene.
Add Fat to Cooked Tomatoes: Combining cooked tomatoes with a healthy fat like olive oil boosts the body's absorption of fat-soluble lycopene.

Understanding Vitamin C and Heat

Vitamin C, also known as ascorbic acid, is water-soluble and heat-sensitive. When exposed to high temperatures, particularly for extended periods, it begins to degrade. Because it is also water-soluble, it can leach out of food and into the cooking water. The degree of vitamin C loss depends on the cooking method, temperature, and duration.

The Impact of Cooking on Tomato Nutrients

When it comes to tomatoes, cooking doesn't simply destroy nutrients. While vitamin C content decreases, another vital nutrient becomes more available. Tomatoes contain lycopene, a potent antioxidant and carotenoid responsible for the fruit's red color. Lycopene is located within the thick cell walls of the tomato. The heat from cooking breaks down these cell walls, allowing for better release and absorption of lycopene by the human body. Cooking can increase lycopene content by more than 50%. This creates a nutritional trade-off: a reduction in vitamin C for a significant boost in lycopene.

Lycopene: The Powerful Antioxidant in Cooked Tomatoes

Lycopene's benefits are numerous, and its enhanced bioavailability in cooked tomatoes is a key reason why many chefs and nutritionists advocate for including both raw and cooked tomato products in a diet. Research has linked lycopene consumption to a lower risk of several chronic diseases, including heart disease and various types of cancer. Studies have suggested a link between higher lycopene intake and a reduced risk of prostate cancer. The antioxidant properties of lycopene protect cells from damage caused by free radicals. To maximize absorption, especially of lycopene, cooking tomatoes with a small amount of healthy fat, like olive oil, is beneficial, as carotenoids are fat-soluble.

Comparison of Nutrients in Raw vs. Cooked Tomatoes


Feature	Raw Tomatoes	Cooked Tomatoes
Vitamin C Level	Highest	Reduced (due to heat sensitivity)
Lycopene Bioavailability	Lower	Significantly Higher (heat breaks down cell walls)
Best for Antioxidant Lycopene?	No	Yes
Cooking Time Impact	Not applicable	Longer cooking = more vitamin C loss, more lycopene release
Best for Overall Vitamin C?	Yes	No

Which Cooking Methods Preserve the Most Nutrients?

The method used to cook tomatoes can significantly affect how many nutrients are retained.

Steaming and Microwaving: These methods are generally the best for preserving water-soluble vitamins like vitamin C because they use less water and have shorter cooking times. When microwaving, using a minimal amount of water can be very effective.
Boiling: This method leads to significant nutrient loss. Water-soluble vitamins leach out into the cooking water, which is often discarded. Prolonged boiling also accelerates the degradation of vitamin C. To mitigate this, consider using the cooking water in soups or sauces.
Roasting and Stir-frying: These methods use dry heat, which can degrade vitamin C, but if done quickly, they can be a moderate option. Adding tomatoes to a stir-fry towards the end can help. Roasting tomatoes can also concentrate flavors and release lycopene, especially when a healthy fat like olive oil is added.

How to Maximize the Nutritional Benefits

For a balanced intake of nutrients, it's wise to enjoy tomatoes in various forms. This ensures one benefits from both the high vitamin C levels of raw tomatoes and the superior lycopene absorption from cooked preparations. Here are some tips:

Mix it up: Incorporate raw tomatoes into salads and sandwiches while also enjoying cooked tomato sauces on pasta or in stews.
Add healthy fats: When cooking tomatoes, including a bit of olive oil can significantly increase the absorption of lycopene.
Cook quickly: Opt for shorter cooking times and lower temperatures whenever possible to preserve more vitamin C.
Don't discard the liquid: If you boil tomatoes, save the cooking liquid to use in a broth or soup, as it will contain some of the leached vitamins and minerals.

The Final Verdict

In conclusion, the answer to "does cooking tomatoes destroy vitamin C?" is a qualified 'yes.' However, this doesn't tell the whole story. While some vitamin C is lost, the cooking process makes another powerful antioxidant, lycopene, much more available for your body to absorb. A balanced approach that includes both raw and cooked tomatoes in a diet is the best way to reap the full spectrum of nutritional benefits this versatile fruit offers.

Authoritative Link: Harvard T.H. Chan School of Public Health: Vitamin C

Frequently Asked Questions

It's best to eat both. Raw tomatoes provide higher levels of vitamin C, while cooked tomatoes offer more bioavailable lycopene. A balanced diet incorporating both forms ensures one gets the maximum nutritional benefits.

Both frying and boiling cause a significant loss of vitamin C due to high heat, but boiling can be more detrimental if the cooking water, into which the vitamin leaches, is discarded.

The amount of vitamin C lost varies by cooking time and method, but studies show it can range significantly. Prolonged cooking, such as boiling for 30 minutes, can result in substantial losses, sometimes exceeding 50%.

While not all nutrients can be recovered, if you boil tomatoes, you can use the cooking liquid in sauces, soups, or stews to retain some of the water-soluble vitamins and minerals that have leached out.

Lycopene is bound within the thick cell walls of the tomato. The heat from cooking breaks down these walls, releasing the lycopene and making it more readily available for the body to absorb.

Yes, canned tomatoes and other processed tomato products like paste and sauce often have higher levels of bioavailable lycopene compared to fresh tomatoes, due to the heat processing involved.

Yes, adding a healthy fat like olive oil when cooking tomatoes can significantly increase the absorption of fat-soluble carotenoids like lycopene.