Understanding the NOVA Classification System
To understand why canned tuna is not a UPF, it is essential to first grasp the NOVA system, developed by Brazilian public health researchers to categorize foods based on their degree of processing. The system features four distinct groups:
- Group 1: Unprocessed or Minimally Processed Foods. These are whole foods in their natural state or with minimal alterations like drying, crushing, or boiling. Examples include fresh fish, vegetables, and fruit.
- Group 2: Processed Culinary Ingredients. These are substances derived from Group 1 foods through simple processes and are used in cooking, such as oils, salt, and sugar.
- Group 3: Processed Foods. These are relatively simple products made by combining foods from Group 1 and ingredients from Group 2. Canned fish, canned vegetables, and cheese fall into this category. The processing aims for preservation and convenience.
- Group 4: Ultra-Processed Foods (UPFs). This category includes formulations made mostly from industrially derived ingredients that are not typically used in home cooking. They often contain additives like emulsifiers, stabilizers, and artificial flavors to create hyper-palatable products. Examples include soft drinks, chips, and packaged cakes.
The Processing of Canned Tuna: More Simple Than You Think
The journey of canned tuna from the ocean to your pantry involves several steps, but they are generally simple and serve the primary purpose of preservation and safety.
- Preparation: The tuna is received, thawed (if frozen), and then cleaned, gutted, and cut.
- Pre-Cooking: The fish is cooked, often by steam or brine, which helps preserve texture and flavor.
- Filleting and Packing: After cooling, the fish is deboned and packed into cans by hand or machine.
- Adding Liquid and Sealing: Water, oil, or brine, along with salt, is added before the can is hermetically sealed.
- Sterilization: The sealed cans are heat-sterilized under pressure to kill bacteria and ensure a long, shelf-stable product.
This process is straightforward and does not involve the complex, industrial modification of ingredients characteristic of UPFs. The final product is a mix of Group 1 (tuna) and Group 2 (salt, oil) ingredients, placing it firmly in the "processed foods" category.
Canned Tuna vs. Common UPFs: A Comparative Look
| Feature | Standard Canned Tuna (Processed) | Typical Ultra-Processed Food (e.g., a frozen meal) |
|---|---|---|
| Core Ingredients | Tuna, water or oil, salt | Reconstituted meat, fats, sugars, starches, flavorings, emulsifiers, stabilizers |
| Manufacturing Aim | Preservation, safety, convenience | Hyper-palatability, long shelf-life, and cost efficiency |
| Processing Level | Minimal, involving cooking, canning, and sterilizing | Extensive, including extrusion, molding, flavoring, and refining |
| Nutritional Density | High in protein, omega-3s, and micronutrients | Often low in nutrients; vitamins and minerals are frequently added back in ('fortified') |
| Shelf-Life Factors | Preservation through heat sterilization and sealing | Extensive use of chemical preservatives and additives |
When Can Canned Tuna Become More Processed?
While plain canned tuna is not a UPF, some variations require closer inspection. Products with long ingredient lists, such as those that are pre-flavored or come in pouches with sauces, may contain more industrial additives like hydrolyzed protein or flavor enhancers. For example, a tuna salad kit with included mayonnaise and seasonings is more processed than a can of plain tuna, as many store-bought mayonnaises and flavorings are UPFs themselves. To stay on the minimally processed side, check the label and choose products with the shortest, most recognizable ingredient list. A good rule of thumb is to stick to tuna packed in water or olive oil with only salt added.
Conclusion
Based on the widely accepted NOVA classification, canned tuna is best described as a processed food, a category distinct from ultra-processed foods. The simple and minimal processing involved in canning—primarily cooking and preserving—does not meet the criteria for a UPF, which is characterized by extensive industrial techniques and the use of numerous manufactured ingredients. While different preparations exist, opting for plain canned tuna packed in water or olive oil ensures you are consuming a nutritious, high-protein food without the heavy industrial additives associated with UPFs. Ultimately, a balanced diet can include processed foods like canned tuna, while focusing on limiting intake of true ultra-processed items. Learn more about different food processing levels at Harvard Health.
