Decoding Labels: What to avoid in canned tomatoes?

October 18, 2025 •

5 min read

Canned tomatoes are a kitchen staple, valued for convenience and consistent flavour year-round. Yet, while some brands offer pure, wholesome tomatoes, others contain a range of hidden additives that can compromise their nutritional value and your health. Knowing what to avoid in canned tomatoes can make a significant difference in your diet.

Quick Summary

Making healthier choices with canned tomatoes requires careful label reading to avoid excess sodium, unnecessary added sugars, and potential BPA exposure. Opt for minimally processed versions in safer packaging like glass jars or cartons for a purer, more nutritious pantry staple.

Key Points

Check for Hidden Sodium: Look for 'no salt added' or 'low sodium' on the label to avoid excessive salt, which can affect blood pressure.
Avoid Unnecessary Sugars: Scrutinize ingredient lists, especially on tomato sauces and pastes, to ensure no sugar has been added to balance acidity.
Choose BPA-Free Packaging: Opt for brands labeled 'BPA-free,' or choose alternatives like glass jars or aseptic cartons to minimize chemical exposure.
Prioritize Minimal Additives: The healthiest options contain just tomatoes, and perhaps salt or basil, with minimal preservatives like calcium chloride.
Inspect Can Integrity: Always avoid cans that are dented, bulging, or leaking, as this can indicate potential bacterial contamination, including botulism.
Consider Heavy Metal Risks: Be mindful that some studies have detected heavy metals in canned products; choosing alternative packaging can reduce this risk.

The Hidden Ingredients in Canned Tomatoes

When you pick up a can of tomatoes, you might assume the contents are simply tomatoes. However, many products on the market contain a variety of additives that can impact both flavour and nutritional content. A simple review of the ingredient list can reveal a lot about the quality of the product inside.

The Sodium Problem: More Than You Think

Salt is often added to canned foods as a preservative and flavour enhancer. While this isn't an issue for everyone, many people on a low-sodium diet are surprised by how much is in a single serving. Standard canned tomatoes can contain anywhere from 100 to 300 milligrams of sodium per serving, representing a notable portion of the daily recommended intake. For those with high blood pressure, excessive sodium intake from multiple sources can be a significant concern. To make a healthier choice, look for labels that explicitly state "no salt added" or "low sodium". For standard cans, draining and rinsing the contents can help reduce some of the sodium content.

The Sweet Deception: Unnecessary Added Sugars

Added sugars, including high fructose corn syrup, are sometimes included in canned tomato products to balance the natural acidity of the tomatoes. This is most common in prepared sauces and pastes. While natural sugars are present in all tomatoes, deliberately added sweeteners contribute to overall sugar intake, which is a key concern for managing weight and diabetes risk. For a more wholesome option, choose products with an ingredient list that only includes tomatoes (and possibly salt or citric acid). Always check the nutrition facts panel for the "Added Sugars" line to make an informed decision.

The Preservative Question: Calcium Chloride and Citric Acid

Calcium chloride is a firming agent commonly added to canned diced tomatoes to help them hold their shape during processing. While not harmful, this can be problematic if you're making a sauce where you want the tomatoes to break down completely, such as in a smooth pasta sauce. Citric acid is another additive used to maintain acidity and preserve colour. These are generally considered safe, but the most versatile and minimally processed options (like whole peeled tomatoes) often contain fewer additives.

The Packaging Perils: BPA and Heavy Metals

The container holding your canned tomatoes can be just as important as the ingredients inside. Can linings can be a source of chemical exposure, while the product itself can pick up trace elements from its environment.

Understanding BPA in Can Linings

Bisphenol A (BPA) is an industrial chemical used in the lining of some metal food cans to prevent corrosion. As tomatoes are acidic, they can cause BPA to leach into the food. BPA has been linked to potential endocrine disruption and may be associated with heart disease and diabetes. Many manufacturers have moved to BPA-free liners, often advertising this on the packaging. However, some alternatives, such as Bisphenol S (BPS), may also have health concerns. For those wishing to completely avoid can-lining chemicals, alternatives like glass jars or aseptic cardboard cartons (e.g., Pomi, Mutti) are excellent choices.

The Risk of Heavy Metal Contamination

Some studies have indicated that canned tomato products may contain trace levels of heavy metals like lead and cadmium, though typically within regulatory limits. This can occur from environmental pollution picked up by the plants, or from contamination during processing and packaging. Choosing certified organic products and alternative packaging materials like glass can help minimize exposure to heavy metals. Continued monitoring is recommended by health authorities to ensure food safety.

Your Healthy Canned Tomato Checklist

To ensure you're picking the best and healthiest canned tomatoes, keep this checklist in mind while shopping:

Read the ingredient list first. Choose products with the shortest, simplest list, ideally just tomatoes, water, and perhaps salt or basil.
Search for "no salt added" versions. Control the sodium content yourself by seasoning to taste.
Opt for "BPA-free" packaging. If you're particularly concerned, choose glass jars or cartons.
Avoid certain additives. If you want a sauce that breaks down smoothly, avoid products with added calcium chloride.
Inspect the container for damage. Reject cans that are dented, bulging, or leaking, which can indicate contamination.
Consider the variety. Whole peeled tomatoes are often the least processed and most versatile option.

Canned vs. Alternatives: What’s the Better Choice?

Choosing between canned, fresh, and other packaged tomato products depends on your priorities for flavour, nutritional profile, and safety. Here's a quick comparison:


Feature	Canned Tomatoes	Fresh Tomatoes	Alternative Packaging (Jars/Cartons)
Convenience	Excellent; long shelf life and pre-processed.	Requires washing, chopping; seasonal.	Excellent; long shelf life, pre-processed.
Nutritional Profile	Cooked process increases bioavailability of lycopene.	Higher in water-soluble vitamins (C) but lower lycopene.	Similar to canned; depends on processing.
Flavour	Consistent year-round; flavour often more concentrated.	Varies by season and ripeness; can be watery.	Often described as having a fresher, less metallic taste.
Additives	Can contain high sodium, added sugar, preservatives.	None, unless you add them yourself.	Typically minimal additives; always check the label.
Packaging Concerns	Risk of BPA in can linings and heavy metals leaching.	No packaging concerns.	Generally safer, often BPA-free linings or no linings.
Price	Affordable; often cheaper than fresh out of season.	Can be expensive depending on the season.	Often higher priced than standard cans.

Conclusion: Making Informed Choices

Canned tomatoes can certainly be a convenient and nutritious pantry staple, but not all are created equal. By becoming a discerning label reader, you can easily avoid unnecessary additives like high sodium and added sugar. For those with heightened concerns about packaging materials, opting for BPA-free cans, glass jars, or cartons provides a solid alternative to traditional cans. The key is to look beyond the marketing and focus on the ingredient list and packaging integrity. Whether you are creating a quick weeknight sauce or stocking your pantry, a few extra seconds spent scrutinizing the options will result in healthier, more wholesome meals for you and your family. For more guidance on healthy eating, visit resources like the American Heart Association's website.

Frequently Asked Questions

The primary red flags are high sodium content, added sugars, and a long list of ingredients. For packaging, look for 'BPA-free' labels.

While 'BPA-free' is a step in the right direction, some manufacturers use alternative chemicals like BPS, which may also have health concerns. Glass jars or cartons are often considered the safest alternative.

For products like beans, rinsing can significantly reduce sodium. However, for canned tomatoes, where the salt is absorbed into the fruit itself, the effect may be less dramatic. Choosing 'no salt added' is the best option.

Some diced canned tomatoes have calcium chloride added to help them maintain their shape during processing. This additive can prevent them from breaking down properly during cooking, resulting in a firmer texture.

Check for visual signs of damage. Any can that is dented (especially on seams), bulging, leaking, or rusted should be discarded immediately.

Organic certification ensures the tomatoes were grown without synthetic pesticides, but it doesn't guarantee the safety of the can lining or prevent high sodium content. You must still read the label for additives and check for BPA-free packaging.

Fresh is often best for some nutrients like Vitamin C. However, canning preserves lycopene, an antioxidant that is actually more bioavailable when cooked. The healthiest option depends on the preparation and the specific nutrients you are prioritizing, along with avoiding unhealthy additives in canned versions.