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Telegraph
30-05-2025
- Health
- Telegraph
Is tinned or fresh tuna healthier? The answer may surprise you
Tuna fish is a much-loved British staple. Whether it's smashed with a dollop of mayo or added to a Niçoise salad, one in five of us eats it at least once a week. Even non-fish lovers will venture into tuna territory. Like all fish it has a glowing health halo. It's full of protein, is leaner than chicken, beef and pork and then there's all the omega-3 fatty acids in the oily varieties that are excellent for our heart and brain. It's often highly revered in weight loss groups, too, for its helpful role in shifting the scales, reflected by the phrase 'if it swims, it slims'. Classed as an oily fish until 2018, the UK then changed its tune on tuna and recategorised it as 'other white fish, shellfish or fish dishes' after finding that its concentration of omega-3s wasn't as high as the likes of salmon, sardines and trout. But first comes first – which is healthier the stuff that comes in a tin or straight out of the sea? Which is better for you – fresh or tinned? Fresh – is higher in fat but also higher in minerals 'Fresh tuna tends to be higher in fat, thus higher in calories,' says Baukje de Roos, a professor of human nutrition at The Rowett Institute. Per 100g portion, fresh tuna contains around 130 calories and 1.5g of fat, compared to around 110 calories and 1g of fat in tinned. However, as a result of its higher fat content, fresh tuna also contains more omega-3 fatty acids and vitamin D, she notes. Yellowfin and albacore are the most commonly available types of fresh tuna available in supermarkets and are generally sold as steaks or diced but there are four other options that are fished for us to eat, including bluefin, which is often the type served in restaurants, and bigeye, though this option is more commonly eaten in Japan and the US. Larger varieties of tuna, such as bluefin, are higher in mercury than smaller types like skipjack, which usually come in tinned form, Prof de Roos adds. Tinned – has less mercury but hold the brine Most types of tinned tuna are skipjack, which is the smallest and most abundant type of tuna. This type should contain smaller amounts of mercury in comparison to larger varieties, which tend to be reserved for serving fresh. While fresh is generally higher in omega-3s, tinned tuna in oil can retain similar levels of these healthy fats, though they will be depleted in spring water and even more so in brine, notes Gunter Kuhnle, a professor of nutrition and food science at the University of Reading. Additionally, it's worth bearing in mind that tinned tuna in olive oil contains an extra 100 calories and 11g of fat, while tinned tuna in brine contains slightly more salt (0.1g). But, overall, tinned tuna is the more healthy and convenient cupboard staple, says Alison Clark, a registered dietitian and spokesperson for the British Dietetic Association. ' Tinned is brilliant for a handy store cupboard, high protein, lean source of protein to grab as part of a quick, balanced meal,' she says. This table shows the nutritional breakdown per 100g of fresh versus tinned tuna: The health benefits of tuna 1. It's a high-quality protein and low in fat Protein is a type of macronutrient (along with fats and carbohydrates) that our bodies need in large amounts. It is responsible for maintaining, growing and repairing bones, muscle and skin, while also supporting our immune system to function normally. Tuna is a particularly dense source of protein, containing a hefty 25g per 100g per can, or around 30g per 100g when eaten fresh – more than found in the same sized serving of chicken (22g) or beef (21g). Further boosting its credentials is that it also contains significantly less fat than those options (around 1g, compared to 3g in chicken and 10g in beef), supporting heart health. 'All fish are a lean source of high quality protein [and] relatively low in saturated fat,' confirms Professor de Roos. 2. It's full of vitamins and minerals 'Tuna is also a good source of vitamin D (found predominantly in the fattier species [of fish]), vitamin B12, B3 and selenium,' Prof de Roos notes. Vitamin D is vital for healthy bones, teeth and muscles but notoriously difficult to get enough of through our diet – and sunlight is our main source in the UK from April to September. However, a 100g portion of tuna contains up to 70 per cent of what we need per day. Tuna is also rich in B vitamins and provides all the vitamin B12 that you need in a day, which is essential for a healthy brain, nervous system and red blood cell formation. Being deficient in B12 can lead to anaemia, which causes the body to produce abnormal red blood cells that can't function properly, says Clark. 'It leaves you just feeling absolutely rotten – it can lead to real tiredness and brain fog.' The fish itself is also a rich source of the mineral selenium, with each 100g portion containing more than the recommended daily intake. 'You don't need it in large quantities but the quantities that you should have are actually vital in the body,' Clark explains. 'It goes on to make glutathione peroxidase, which is really important for immunity and mood.' 3. It's low in calories and can help with weight loss Tuna has just 110 calories per 100g, which is less than found in the same amount of chicken (115 calories) or beef (174 calories). 'We know that protein is really good for satiety, so it helps to make you feel full without containing a lot of calories,' Clark says. This means it can help ward off hunger pangs that lead to overindulging in snacks or serving up a second portion at dinner. 'That's really important because obviously we know that obesity is a major problem, not only in the UK, but worldwide,' Clark adds. What are the health risks of tuna? 1. It contains mercury Mercury is a naturally-occurring heavy metal that makes its way into the ocean through coal burning and industrial waste, as well as natural events like volcanic eruptions. It then accumulates in fish as it moves through the food chain – being consumed by plankton, small fish, bigger fish and ultimately predatory fish like sharks, marlin, swordfish and tuna. This can pose a risk to our health if we eat too much. 'Mercury can bind to proteins in the body and stop them from working,' Prof Kuhnle explains. 'Methylmercury – one form of mercury – is neurotoxic and can inhibit development in children.' For this reason, the NHS advises that women who are pregnant or trying for a baby have no more than four tins of tuna, or two portions of fresh tuna, per week. There is no official maximum limit for other groups but Professor Kuhnle urges caution. Studies have also linked mercury with cardiovascular disease, as well as problems for the brain and nervous system. 'The mercury in tuna will affect everyone, so it's not just pregnant women (or those trying for a baby) who should watch the amount they eat and not eat excessive amounts,' he says. 2. It can be high in salt 'Other issues could be high sodium in some tinned tuna, if preserved in brine,' Professor Kuhnle says. Tinned tuna in brine contains a decent amount of salt, with 1g per 100g serving – saltier than a packet of ready salted crisps or McDonald's fries, both of which contain 0.6g. Tuna in water or oil contains slightly less, at 0.9g per 100g. The NHS recommends having no more than 6g of salt per day, which is around one teaspoon, because too much can lead to high blood pressure and increase the risk of heart attacks and strokes. 3. It's not an oily fish Up until 2018, tuna was categorised as an oily fish, which are high in omega-3 fatty acids that help to lower blood pressure and prevent heart disease. We're told to eat at least one 140g portion of oily fish per week to harness this heart-supporting effect. However, following in-depth nutritional analysis, health officials reclassified the fish after realising its fatty acid composition was more comparable to a white fish, Prof de Roos explains. This may be problematic for people who assume tuna is an oily fish because 'it doesn't have the same benefits of the oily fish like mackerel, herring, kippers, trout, sardines,' Clark says. 'It's really important to get those oily fish in and the recommendations in the UK are to have two portions of fish per week, one of which should be oily,' she notes. 'We don't eat enough oily fish, and it's so beneficial in so many different ways, such as the omega-3 levels and vitamin D.' Rather being in similar to white fish such as cod, plaice or haddock, tuna actually more closely resembles other predatory fish like shark, marlin and swordfish, as these are also high in mercury, Clark adds. How to ramp up the health benefits of tuna in your diet For a healthy, balanced and filling meal, you ideally want to pair a source of protein, in this case tuna, with a carbohydrate and fibre, Clark says. The carbohydrate could be bread, pita bread, a jacket potato, crackers, quinoa or bulgur wheat, while vegetables like peppers, celery and cucumber, and pulses such as chickpeas, are a great source of fibre, she says. 'If you squeeze in some herbs, seeds and nuts, just to make sure that fibre content is as high as it can be, that's even better,' Clark adds. Tuna is often the fish that's served in sushi, which has become a popular grab-and-go lunch option, but the portion size is small and comes with sushi rice and little fibre, so Clark wouldn't recommend this as a regular lunch. Tuna mayo and sweetcorn is a common combination but to enhance the nutrients, she recommends swapping the mayonnaise for yogurt and adding chickpeas, which will increase the protein, B vitamins and fibre content. Verdict: Is tuna healthy? Tuna is a convenient, delicious and healthy source fish that we can enjoy as part of a balanced diet, says Clark. It's an excellent source of lean protein, as well as vitamins and minerals that keep our bodies functioning optimally. However, the key is how often we eat it. 'I think 'as often as you like' is still not a good idea,' says Prof Kuhnle. He advises that people have no more than twice the recommended limit for women who are pregnant or trying for a baby, which would be no more than eight tins of tuna, or four portions of fresh tuna per week. 'You'd really have to be eating tuna most days to hit maximum intake,' Clark notes. 'Really, we wouldn't want you to be doing that anyway because it would be at the expense of other sources of protein, such as eggs, pulses, oily fish.' So enjoy it, but perhaps not too much.
Press and Journal
24-05-2025
- Health
- Press and Journal
Free meals for three months: Aberdeen University can make it happen - as long as you're willing to eat LOTS OF FISH
Would you like to have free fish-based meals for three months? With the help of Aberdeen University, you can. The university is hoping to underline the benefit of eating more of our local catch as part of a new project. Lucky participants will have a 14-week menu selected for them by the Rowett Institute's dieticians with regular monitoring of the relative changes to their health. The £750,000 project, which is being called the FAMOUS study, is funded by the UK Biotechnology and Biological Sciences Research Council. They say it is codenamed FAM-OUS because it compares fish and meat-based diets. The latest project comes shortly after the Rowett published Scottish Government-funded research showing many vital nutrients are 'lost' because the UK exports so much of the fish caught by our fleets. That report concluded fresh efforts are urgently needed to increase the quantity of fish we eat as a country, which falls significantly short of the recommended intake. The project is specifically aimed at providing strong scientific backing for the heart health benefits of eating fish. The team is looking for healthy, overweight (BMI 25-29.9) 30–65-year-old meat eaters. These people should have elevated blood lipids, sugar, or blood pressure but not be on medication or have any history of heart disease or other inflammatory diseases. They should also not be on medication for cholesterol or lipaemia or taking any dietary supplements. Taking part will involve following different diet plans over set periods and having heart health and gut microbiome changes monitored and assessed. Participants will get a free health check and dietary advice as well as having all their food provided for 14 weeks and expenses covered. It is a menu designed by expert dietitians and nutritionists at the renowned Rowett Institute. Rowett Institute director and one of the FAMOUS study lead researchers, Jules Griffin, said he was 'delighted' with some of the dishes set to be served up to volunteers. They include curries and fish cakes. 'This region produces some of the best fish and seafood in the world and yet many of us eat a rather limited range, perhaps just fish and chips on a Friday,' he said. 'We missing out on some great tasting food. 'But fish is also an important source of vitamin D and polyunsaturated fats. 'They protect us from serious diseases, including cardiovascular disease.' To apply to take part, or find out more, please contact Frank Thies ( or Morven Cruikshank ( Alternatively, visit the Rowett website.
Press and Journal
09-05-2025
- Health
- Press and Journal
Why is cutting back on meat so hard? I helped Aberdeen scientists find out
The first time I tried to go vegetarian, it didn't end well. It was some time ago, and I was dating a woman who was vegetarian herself. As per the rules of love, that meant I was vegetarian too – by proxy, perhaps, but just as committed. Unfortunately, the relationship lasted only slightly longer than the vegetarianism – and indeed may have been cut short by my inability to say no to a bacon buttie. So when Aberdeen's The Rowett Institute – one of the world's leading food research centres – asked if I'd like to take part in a study looking at why people can't stick to vegetarian diets, I jumped at the chance. After my failed flirtation with vegetarianism, this felt like an opportunity to redeem myself – not just in the name of love, but for something bigger – science. The planet, too. As someone who knows that eating meat is bad for the environment but can conveniently forget when cheeseburgers are on the menu, the study felt like a chance to change my habits for the better. The Rowett study, called LESS: Meat (Lived Experience of Sustainability in Scotland), is part of a Scottish Government-backed effort to understand why people don't always stick with sustainable choices, even when they believe in them. With Scotland aiming for a 20% cut in meat consumption by 2030, researchers wanted to explore what gets in the way and what might help us change. 'You might get to the end of the trial and think, 'I never want to do that again,'' Dr David McBey, one of the lead researchers, told me before I started. 'Or you might find that some of the habits stick. We're interested in both.' This wasn't a public health lecture disguised as research. It was, in his words, about the 'lived experience of trying to do the right thing' – of navigating meat reduction in the real world, where cultural habits, convenience, cravings and the occasional bacon buttie all still exist. And crucially, unlike some other trials run by the Rowett Institute, this one didn't provide food. There were no meat-free meal kits, no delivery boxes of pre-approved lentil lasagne. Instead, I had to make all the swaps myself – three days a week, for eight weeks. The idea was to see what that feels like in everyday life. Each week, I logged into an online portal to tick off which days I'd gone meat-free, answer questions about why I'd chosen them and record what I'd eaten. I also completed weekly food recalls and longer surveys at the start and end of the trial. It was all straightforward, and as Dave pointed out, designed to be 'light touch' – just enough to gather insight without overwhelming participants. The tone, too, was supportive. 'We're not judging,' Dave reminded me when explaining the daily compliance tracker. 'We're just interested.' As Dave explained, meat still holds a 'special place' in many people's lives. 'It's not just about taste or nutrition. There's culture and emotion tied up in it – and that's what makes this topic so complex.' His own background – with a PhD in sociology and years working in environmental modelling – helped shape the study's focus on real-world behaviour. 'I eat meat myself,' he said. 'So I know how hard it can be.' Starting the study, I immediately ran into trouble. My first week coincided with a holiday I'd booked to Germany – the land of meat! Fortunately, the friends I stayed with were long-time veggies so were able to expertly guide me. Breakfast was fresh bread with hummus, cheeses and a lot of fake meat slices that were not as bad I expected them to be. For dinner one night, we went to a doner kebab place called Mr Lecker, which translates as Mr Delicious. Here, we had Mr Lecker's locally famous Big Makali hummus wrap. I was delighted to discover that it was, indeed, delicious. I was off to a great start, and things got even easier when I returned to Aberdeen and took control of my shopping list and kitchen again. I dusted off a few old vegetarian recipes. This might say something about me, but a lot of the recipes were tailored to appeal to meat eaters – full of chunky vegetables and savoury sauces. Over the eight-week study I learned a few more that dampened the meat thirsts. Some swaps were easy. Chickpea curry. Macaroni cheese. Mushroom stroganoff. Some swaps I thought would work didn't. Back in the day, I would use Quorn mince, but now found I liked it less than I remembered. Instead, I opted for pulses – black-eyed and butter beans made for a hearty stew when cooked with coriander, chopped tomatoes and a bit of chili pesto. It wasn't all plain sailing. I normally cook an evening meal and leave enough left over for lunch in the office the next day. But because the study called for three meat-free days a week, I couldn't do this if I allocated no-meat days on, for example, Monday, Wednesday and Friday. It was something I would grumble about to Dave during our catch-ups, and in the food questionnaires I diligently filled in. In fact, this was the hardest thing about doing the study – the hassle of switching between codes. It did dawn on me that I could sidestep the trouble by going totally vegetarian, but I wasn't ready to do that. By the end of the eight weeks, I hadn't become a vegetarian. But I was eating less meat – and, crucially, doing it without much resistance. I'd found a few go-to meals I genuinely enjoyed and had conversations with friends about food choices I wouldn't have brought up before. I'd started to see meat as a treat rather than the default. The trick is to keep that going. And this time to do it for myself, rather than someone else. Check out The Rowett Institute's volunteer page to find out how you can take part in ne of its food studies.
