You have probably wondered at some point whether tuna in oil or tuna in brine is healthier. It's not just about taste or calories – there is much more to it. It mainly comes down to omega-3 fatty acids, which are a key reason why tuna is so highly regarded.

Omega-3 – a treasure for your heart and brain

Omega-3 fatty acids are a special type of fats that your body critically needs but cannot produce on its own. This means that you must ingest them through food. When consumed enough, they can contribute to lower cholesterol, better blood circulation, anti-inflammatory effects, improved brain function, and can even alleviate symptoms of depression.

The Harvard School of Public Health states that regular consumption of omega-3 reduces the risk of heart diseases by as much as 36%. Similarly, a study conducted by the American Heart Association confirmed that people who eat fish (especially fatty fish like tuna) at least twice a week live longer and have fewer issues with blood pressure.

Now, let's return to the question – is there more of these beneficial fats in tuna canned in oil or in brine?

A Short Story of Two Cans

Tuna in a can is available in two basic forms: in brine and in oil. The packaging often states vegetable oil, but what does that exactly mean?

The vegetable oil in the can is usually sunflower oil, sometimes mixed with soybean or even rapeseed oil. Brine, on the other hand, is a simple solution of salt in water, which preserves the food but adds a negligible amount of fats.

So – oily tuna has more calories, which you may have already known. But how much more?

Data from the USDA (United States Department of Agriculture) clearly show:

• 1 can (approximately 165 g) of tuna in oil contains around 317 calories,
  
  
• the same amount of tuna in brine only has 150 calories.

Now, let's get to the essence. How much omega-3 does each actually contain?

More Fats Doesn't Mean More Omega-3

A study published in 2011 in the renowned journal Public Health Nutrition surprised many. It showed that tuna in brine retains more omega-3 fatty acids than tuna in oil.

Why?

When tuna is stored in oil, some of these beneficial fats dissolve in the oil – and if you then drain the oil (which most people do), a considerable amount of omega-3 also goes away. On the other hand, fats do not dissolve in brine, so they remain in the fish meat. Therefore – if you drain tuna from oil, you lose more of the benefits than if you drain tuna from brine.

What Do the Numbers Say?

According to a study by the British portal Food Standards Agency, 100 g of tuna contains:

• on average 0.31 g of omega-3 fats in brine,
  
  
• in the oily version, if you remove the oil, only 0.2 g of omega-3.

So, if you are solely looking at omega-3 and want to make the most of it, the answer is clear – choose tuna in brine.

However, this does not mean that tuna in oil is not good. On the contrary – it contains more energy value, which is important for people with higher energy or fat needs. This is especially true for growing children, athletes, pregnant women, and individuals with certain diseases.

Special Cases – When Does Tuna in Oil Have an Advantage?

People with cystic fibrosis (a chronic inherited disease that affects the lungs and digestion) have difficulties absorbing fats. For them, tuna in oil can be a better choice as it helps them obtain what their bodies cannot on their own.

Tuna in oil also contains slightly more vitamin D and selenium, two extremely important substances for bone health, the immune system, and thyroid function.

Selenium is a potent antioxidant – it ensures that free radicals do not cause harm in the body. One can of tuna contains between 40–60 micrograms of selenium, which is 70–90% of an adult's daily requirement.

Folk Wisdom About Fish on the Plate

In folk medicine, every fish is a goldfish as long as it is fresh. Although canned tuna is not fresh, it has a long shelf life due to the method of preservation and retains most of its nutrients well. Many old masters, who learned about healthy eating in their youth the traditional way, knew that fish nourishes the brain, strengthens the blood, and helps "soften the veins."

Even in ancient times, pregnant mothers enjoyed fish soup and dried sardines. Today, tuna, due to its accessibility, has taken on the main role – and for a reason, has kept it.

Other Aspects to Consider When Buying Tuna

Besides the difference between oil and brine, it is also wise to look at:

• the type of tuna (e.g. albacore, skipjack – the former are fattier and larger, the latter more petite),
  
  
• the amount of salt (brine can contain considerable salt, which is not recommended for people with high blood pressure),
  
  
• the quality of packaging (the can should not be swollen or damaged).

Some also fear the mercury content, as tuna, being a larger fish in the food chain, accumulates more heavy metals. However, according to the European Food Safety Authority (EFSA), an adult can consume up to 3 servings of tuna per week without it posing a health risk.

A Conclusion Worth Remembering

If you are concerned about consuming as much omega-3 fats and as few calories as possible, then tuna in brine is your best choice. If you need more energy, vitamin D, and other beneficial fats, then feel free to choose the one in oil – just do not drain it too much.

Regardless of your choice, tuna is a valuable source of proteins and nutrients that offers a myriad of possibilities in the kitchen. Enjoy it with toasted bread, in a salad with beans, with eggs, or as a spread for a snack – every bite counts.

Sometimes it's said: health cannot be made out of a can. But in the case of tuna, it might be quite the opposite – a small can can bring many benefits. Of course, if you know how to choose it correctly.