John West tinned tuna: 13 UK brands to avoid and which ones are actually safe?

From shrinking tins to cheap seed oils filling up your tuna, the UK tinned fish aisle has quietly turned into a consumer trap. In this investigation, we reveal the thirteen popular supermarket products from brands like John West, Princes, and Aldi that you should leave on the shelf, alongside five honest alternatives like Waitrose MSC Tuna Steak and Sainsbury's spring water tuna that are actually worth your money. Which household brand shocked you the most today, and what supermarket product should we put under our investigative microscope next? tinned fish UK, supermarket investigation, John West tuna, Princes mackerel, Aldi fishmonger, best tinned tuna, food shrinkflation UK, saving money on groceries, sustainable seafood UK