Salt raises 'stomach cancer risk'

BBC News - 7 January, 2004

Scientists from Japan's National Cancer Centre Research Institute caried out an 11-year study of 40,000 middle-aged Japanese.

The risk of stomach cancer was one in 500 per year for those men with the highest salt intake - twice the rate for those who ate the least salt.

The research is published in the British Journal of Cancer.

For women, the risk was one in 1,300 per year for those who ate the highest amount of salt, compared to one in 2,000 for those with a relatively salt-free diet.

Common cause of death

The study underlines the importance of limiting salt intake in our daily diet.

Dr Tim Key
Gastric or stomach cancer is the second most frequent cause of cancer deaths worldwide - with an estimated 776,000 deaths in 1996.

Scientists know that high salt intake can induce atrophic gastritis - a precursor to stomach cancer.

Salting, pickling and smoking are traditionally popular ways of preparing food in Japan. Pickled vegetable and noodles are rich in sodium and low in vitamin C.

As the Japanese diet has become increasingly westernised there has been a noticeable drop in the rates of stomach cancer but an increase in the rates of breast and bowel cancers, emphasising the role of diet in the disease.

Lead researcher Dr Shoichiro Tsugane said: "Although there is a steady decline in its incidence, gastric cancer is still the most common form of cancer in Japan.

"In addition to salt intake our study also shows that smoking and low consumption of fruit and vegetables increases the risk of stomach cancer particularly in men."

Dr Tim Key, an epidemiologist for Cancer Research UK, said: "This study shows strong associations of stomach cancer with the intake of highly salted Japanese foods including salted fish and pickled vegetables.

"What we don't know is whether it is specifically the salt in these foods that can cause cancer or a combination of salt and other chemicals.

"In Britain stomach cancer rates are much lower than in Japan and these types of highly salted foods are not widely consumed.

"But limiting salt intake is also important for reducing the risk for high blood pressure and cardiovascular disease.

"The study underlines the importance of limiting salt intake in our daily diet not only to reduce the risk of stomach cancer but also to protect against heart disease."