How healthy are tinned foods?

Because of our hectic lifestyles, the British are eating more processed food than ever. But can we rely on convenience meals for a balanced and healthy diet? Heinz, the tinnedfood giant, believes we can. It claims that products such as baked beans and tinned soup contribute towards the Government's five-a-day campaign, aimed at getting us to eat more fruit and vegetables.

It is often assumed that tinned foods are a poor source of vitamins and minerals, yet, in many cases, they provide similar amounts of these essential nutrients as their fresh equivalents, and are often a good source of protein and fibre.

As Dr Hannah Theobald of the British Nutrition Foundation says: "Canned foods are often overlooked as an economical source of nutrients, but the very process of canning preserves nutrients and in some cases actually makes them more available."

Most products are tinned immediately or very soon after harvest, when nutrient concentrations and eating quality are at their highest. This ensures that many of the vitamins and minerals are retained, whereas concentrations of some vitamins can decrease by 50 per cent within seven days of harvest when stored at room temperature before packaging.

The problem is that most tinned vegetables and meals contain more salt than fresh or home-cooked equivalents. However, it is possible to find foods from each of the main groups needed for a balanced diet, especially if you choose products with low salt, no added salt or sugar, or foods tinned in fruit juice or water rather than syrup or brine.

Many tins carry panels detailing Guideline Daily Amounts (GDAs) for calories, fat and salt. Take these into consideration. Men should aim for 2,500 calories a day and no more than 95g of fat or 7g of salt; women should have 2,000 calories and no more than 70g of fat and 5g of salt. Here are the best buys ...

Fish: Canned fish such as kippers contain omega-3 fatty acids and higher amounts of calcium than fresh fish. All tinned fish is a good source of vitamin B12 and D, but is higher in salt than fresh. Tinned salmon is lower in fat and saturated fat than fresh, steamed salmon and has 50 per cent more vitamin D, 90 per cent more iodine, 75 per cent more calcium and 50 per cent more vitamin A.

Meat: Corned beef is a rich source of vitamin B12 and protein, and provides 50 per cent more vitamin D, zinc, vitamin E and iron than the deli-bought variety. However, it contains more fat and saturated fat.

Fruit: Tinned prunes are a good source of iron and folic acid. Grapefruit and orange are rich sources of vitamin C. Strawberries and blackcurrants are rich in antioxidants, fibre and vitamin C. Two to three tablespoons of tinned berries count as one portion towards the recommended five a day.

Apricots are similar nutritionally to the fresh fruit when whole with juice. They contain twice as much vitamin C weight for weight as fresh apricots and nearly twice as much calcium. However, they don't contain as much fibre.

Vegetables: Tomatoes are a good source of vitamin C and rich in lycopene, which is more readily available to the body from tinned foods than fresh. They also contain over a third more calcium and magnesium than fresh ones. Sweetcorn and chickpeas provide minerals and fibre and are low in fat.

Carrots do not contain as much beta-carotene or folic acid as fresh ones boiled in unsalted water. Peas provide twice as much beta-carotene, a third more calcium and 20 per cent more iron than when fresh and boiled, and are good source of fibre (more than 3g/100g).

Buy baked beans with reduced salt and sugar, which count as one of the five-a-day target.

More details are available from: www.nutrition.org.uk or Canned Food UK (0800 243 364); www.cannedfood.co.uk.