How much tuna is safe to eat in a week? As sales of the tinned fish soar, we ask the experts

Whether mixed with mayonnaise and served on a sandwich, stirred into baked pasta, or poured over a baked potato, tuna is a simple but versatile store cupboard staple.

It’s no surprise that it’s the second most eaten fish in the UK, with salmon taking the top spot.

Despite many fears about overfishing and high mercury levels, tuna sales have skyrocketed in the past two years.

Figures published by Tesco have revealed how demand for canned fish has increased over the last two years. Sales increased nearly 18 percent; This is equivalent to more than two million kilograms.

This increase is largely due to a new health-conscious audience on social media, according to Tesco canned fish buyer Lee Bannerman.

Fiona Harrold, nutritionist at restaurants in Leon, says: ‘One of the reasons why tuna remains such a popular food is that it is nutrient-dense yet convenient, affordable and versatile.

‘For many people, it offers an easy way to increase protein intake without relying on heavily processed foods.’

So how healthy is tuna and should we worry about eating too much of it?

What makes tuna so special?

Twilight actor Robert Pattinson once admitted to eating tuna straight from the can; such was his love for canned fish.

Although its salty smell and association with cat food may bother some people, tuna is rich in Vitamin D, which is vital for healthy bones and muscles, and selenium, a natural antioxidant that strengthens the immune system.

It also contains iron, which is essential for healthy blood, potassium for heart health, and omega‑3 fatty acids, which help regulate inflammation and support brain function. It helps cells function properly.

100 grams of canned tuna in brine or spring water provides between 25 grams and 30 grams of protein, less than 1 gram of fat and approximately 110 calories. If tinned in oil, it has the same amount of protein, but about 6 grams of fat and 160 calories.

Nutritionists generally recommend low-calorie protein sources for a healthy diet. What’s more, one box is unlikely to set you back more than half a kilo.

Is canned tuna less healthy than fresh?

Jumpfish, often labeled as ‘tuna chunks’ in the UK, makes up around 90 per cent of canned tuna, usually sold in brine, oil or spring water.

Albacore or white tuna — often labeled as tuna steak — contains more omega-3s than skipjack but also accumulates slightly more mercury. It is known for its firm, meaty texture and mild, buttery taste.

While canned tuna is generally more popular than fresh tuna due to its affordability and long shelf life, fresh tuna also has some extra health benefits.

In the UK, the main tuna brands are John West and Princes, and most supermarkets also offer their own tuna.

‘The canning process squeezes out natural oils rich in DHA and EPA, fats linked to brain and heart health, and often adds less healthy vegetable oils or brine,’ says Dr Carrie Ruxton, dietitian and co-founder of gym SALT St Andrews.

Fresh tuna, such as yellowfin, bigeye and bluefin, are prized for their meaty texture and high concentration of heart-healthy omega-3s, as well as Vitamin D and B vitamins.

Larger predatory species, such as bluefin and bigeye, are rich in healthy fats but also have higher levels of mercury and other pollutants; We will touch on this issue later.

The canning process involves first heating the tuna twice to separate the meat from the bones, and then sterilizing it a second time before the can is sealed.

This process can damage heat-sensitive B vitamins, but there is still enough vitamin left and Vitamin D and mineral levels remain essentially unchanged.

‘Tinned tuna can sometimes be a more practical and accessible option, helping people consume more protein and less ultra-processed foods overall,’ Ms Harrold adds.

Can you eat tuna every day?

The question of how often you can eat tuna continues to be a matter of debate among nutritionists and health experts.

The main concern is mercury. Tuna contains relatively high levels of mercury due to its position in the food chain, accumulating mercury from smaller fish and crustaceans.

Eating too much can lead to methylmercury poisoning, which affects the brain and nervous system. In adults, this condition can cause tingling, tremors, and memory problems. It is especially risky during pregnancy and early childhood, when it can affect neurological development.

Dr Ruxton says: ‘As some types of fish, including tuna, can pick up contaminants, it is not recommended to eat them every day. But if you eat less than four 140g cans a week you don’t need to worry.’

The NHS recommends eating at least two portions of fish a week, one of which should be oily fish. Fresh and frozen tuna count as oily fish, but canned tuna does not because most of the oil is removed during processing.

Pregnant women or those trying to become pregnant should eat no more than four cans or two tuna steaks per week.

There is no definitive limit for healthy adults, but experts recommend variety. Nutritionist Ms. Harrold says two to three servings of low-mercury tuna a week, along with other fish such as sardines, salmon and anchovies, is a reasonable guideline.

For vegetarians, Dr Ruxton recommends marine omega-3 supplements derived from fish or algae.

Oil, salt water or spring water?

Canned tuna usually comes packed in brine, spring water, or oil; The main difference comes down to taste preference and nutritional value.

Tuna in spring water is the lightest option. Draining eliminates some water-soluble omega-3s, but remains the best option for calorie-sensitive diets.

This option is best for recipes where you still plan to add a creamy dressing, like tuna salad with traditional mayonnaise, tuna melts, or pasta casserole.

Tuna preserved in salt brine is similar to spring water in terms of calories, but is higher in sodium, which can raise blood pressure; Tuna in sunflower or olive oil is the highest in calories and fat.

Since good fats are insoluble in water, draining oil-packed tuna helps retain its natural omega-3s better than draining water-packed tuna.

Bette Midler is known for her seven-ingredient tuna salad. ‘For starters, you should use tuna in oil. Soak this tuna in water,” he said in an interview in 2000.

This is best for dishes where fat may be a feature, such as Mediterranean pasta, Nicoise salad, or eating it on its own with crusty bread. Tuna packed in olive oil is widely considered the most delicious fish.

Is tuna good for cholesterol?

Tuna is generally considered a very heart-healthy choice and can be included in a cholesterol-conscious diet.

It contains moderate levels of dietary cholesterol, typically around 30-50 mg per 100 g, depending on the type and preparation, but the medical consensus is that dietary cholesterol has a much smaller effect on blood cholesterol levels than saturated fats.

To keep your tuna dishes cholesterol-friendly, it’s best to choose tuna packed in spring water or brine instead of oil, and be careful with high-fat condiments like standard mayonnaise.

What should you pair tuna with?

To make the most of tuna’s health benefits, experts recommend pairing tuna with avocados, leafy greens, and whole grains to add fiber, carbohydrates, and healthy monounsaturated fats.

Because tuna is a lean, protein-rich fish, these combinations create a perfectly balanced, satisfying meal that boosts your daily nutrition.

Mrs. Harrold saysOne of the healthiest ways to eat tuna is as part of a Mediterranean-style meal, rather than highly processed sandwiches or pasta dishes made with refined ingredients.