An estimated 14% of stomach cancers in the UK - one in seven cases - could be avoided by reducing salt intake to recommended levels, it has been claimed.
People in the UK consume an average of 8.6g each a day, much of it hidden in processed food.
This is 43% higher than the maximum recommended amount of six grams, equivalent to one level teaspoonful.
Better "traffic light" food labelling is needed to reduce the number of stomach cancers linked to salt, experts have said.
A standardised form of colour-coded food labelling would help consumers monitor their consumption of salt, sugar and fat, according to the World Cancer Research Fund (WCRF).
Kate Mendoza, head of information at the charity, said: "Stomach cancer is difficult to treat successfully because most cases are not caught until the disease is well-established.
"This places even greater emphasis on making lifestyle choices to prevent the disease occurring in the first place - such as cutting down on salt intake and eating more fruit and vegetables."
She added: "Because around three-quarters of the salt we consume is already in processed food when we buy it, WCRF would like to see traffic light labelling on the front of food and drink packaging to give clear guidance on the levels of salt as well as sugar, fat and saturated fat."
Each year in the UK around 7,500 new cases of stomach cancer are diagnosed and almost 5,000 people die from the disease.
Cutting salt intake to 6g a day could prevent 1,050 of these cases, according to the WCRF.
Excess salt is also linked to high blood pressure, the main cause of strokes and a significant cause of heart disease, as well as osteoporosis and kidney disease.