What is processed food, anyway?
To understand whether canned food is processed, one must first grasp the broad definition of 'processed food.' The term is often used with negative connotations, but in reality, nearly all food we consume undergoes some form of processing. Processing simply means any deliberate change to a food's natural state. This includes: peeling, cutting, cooking, drying, freezing, and, of course, canning.
The Academy of Nutrition and Dietetics outlines a spectrum of processing levels, from minimally processed to ultra-processed. Canned foods, particularly those with simple ingredients like beans or tomatoes, generally fall into the minimally to moderately processed categories. In contrast, ultra-processed foods are those made with many ingredients not typically used in home cooking, such as preservatives, high-fructose corn syrup, and artificial flavors. Examples of ultra-processed items include sugary cereals, hot dogs, and packaged snacks.
The process of canning: A closer look
The canning process is designed to preserve food for long-term storage, and it typically involves three key steps: processing, sealing, and heating.
- Processing: Foods are prepared by being washed, peeled, chopped, and sometimes cooked. This initial alteration is a form of processing.
- Sealing: The food is then sealed in an airtight container, usually a can. This prevents microorganisms from contaminating the food.
- Heating: Finally, the sealed cans are heated to a high temperature, killing any remaining bacteria and creating a vacuum seal. This step ensures the food is commercially sterile and safe to eat for an extended period.
This method of preservation is effective because it removes air and heat-treats the food, eliminating the need for many of the preservatives found in more heavily processed items. Therefore, many canned goods, such as fruits in their own juice or no-salt-added vegetables, can be considered minimally processed.
Canned vs. Fresh vs. Frozen: A nutritional comparison
While some fear that the canning process destroys all the nutritional value, research shows this is largely a myth. While some water-soluble vitamins like Vitamin C and B vitamins can be sensitive to the high heat used in canning, other nutrients, including fat-soluble vitamins, minerals, and fiber, are well-retained. In fact, some antioxidants, like lycopene in tomatoes, may become more bioavailable after heating.
Comparison of processing and nutrition
| Feature | Fresh Food | Canned Food | Frozen Food |
|---|---|---|---|
| Processing Level | Minimal (washing, trimming) | Minimal to moderate (heated, sealed) | Minimal (washed, blanched, frozen) |
| Nutrient Retention | Highest at peak ripeness; declines over time. | High; heat may reduce some water-soluble vitamins. | High; flash-freezing locks in nutrients at peak. |
| Cost | Can be higher, especially when out of season. | Often the most affordable option. | Moderately priced; consistent availability. |
| Shelf Life | Shortest | Longest (1-5+ years). | Long (8-10 months, typically). |
| Prep Time | Requires cleaning, peeling, chopping. | Minimal; often ready to heat. | Minimal; may require thawing. |
| Additives Concern | Low | Potential for added salt or sugar; requires label reading. | Generally low; depends on product. |
How to make healthy canned food choices
Reading the product label is key to making healthy choices when buying canned goods. Look for items marked “low sodium,” “no salt added,” or fruits canned in 100% juice or water, not heavy syrup. Rinsing canned vegetables and beans can also help reduce their sodium content significantly. The perception that canned foods are inherently unhealthy is a misconception rooted in lumping all processed items together. A can of no-salt-added beans is a far cry from a can of ravioli packed with high-sodium sauce.
Potential risks and considerations
While the risk is low, it is crucial to be aware of the extremely rare but serious risk of botulism from improperly canned foods. Commercially canned goods are very safe, but home canners must follow strict safety guidelines. Never consume food from a can that is bulging, dented, or leaking, as this could indicate contamination.
Another consideration is BPA (bisphenol-A), a chemical historically used in the lining of some food cans. While many manufacturers have moved to BPA-free linings, some still use it. If this is a concern, check for BPA-free labels. For further reading on food processing classifications, the Food Standards Australia New Zealand offers a detailed overview of different processing methods and their implications.
Conclusion: Canned food is processed, but not always unhealthy
Ultimately, the answer to the question "Is canned food considered processed?" is yes. However, this is not the full story. The term 'processed' exists on a wide spectrum, and canning is a preservation method that falls closer to the minimal end of the scale for many products. Canned goods offer an affordable and convenient way to include nutrient-dense foods in your diet, often retaining nutrients comparable to fresh or frozen options. By reading labels and choosing wisely, you can easily incorporate canned foods into a balanced and healthy lifestyle.
