According to experts, people who regularly eat foods, such as processed soup, that are high in salt have a greater risk of developing stomach cancer.
Dr Rachel Thompson, science programme manager for the World Cancer Research Fund (WCRF), said some leading brands contain half the recommended daily maximum intake of salt in a single serving.
Increased blood pressure and the risk of stroke and heart disease are all linked to salt; however, scientists now believe it is a cause of stomach cancer.
Other salt-preserved foods include some hams and sausages, as well as pizza, some ready meals and breakfast cereals, said Dr Thompson.
The recommended daily amount of salt for adults is no more than 6 g, although people consume an average of 8.6 g.
Dr Thompson said: "Fresh vegetable-based soups tend to have less salt than tinned cream-based soups that include bacon or ham, but even some of the healthier brands of vegetable soups still contain over a third of our recommended daily intake. This is why it's so important for people to always check the labels of products.
"Our daily intake should be no more than 6 g but we actually need far less than this."