Hot topic - Salt and stomach cancer risk
9 January 2004 - written by Bupa's Health Information Team
A paper published in the British Journal of Cancer has suggested that people who eat high levels of salt on a daily basis raise their risk of developing stomach cancer. This research was based upon studying 39,065 people in Japan - a country well known for its highly salted diet.
How much does salt raise the risk of stomach cancer?
To investigate whether a high salt intake is linked to a raised risk of stomach cancer, researchers in Japan studied 18,684 men and 20,381 women aged 40-59 years. They measured the amount of salt the people ate per day and followed them for an 11-year period.
The researchers found that men who ate less than 6g of salt a day had a risk of one in 1,000 of developing stomach cancer. Men who ate between 12-15g a day had a risk of one in 500.
While women who ate less than 6g of salt a day the risk of one in 2,000, with the risk rising to one in 1,300 for those who ate 12-15g a day.
What role does salt play in the development of stomach cancer?
Eating high levels of salt may cause the stomach lining to waste away. This condition, known as atrophic gastritis, can lead to stomach cancer.
Because of this, a diet that is high in salt has been thought to increase the risk of developing stomach cancer. In Japan, very salty pickled foods are popular and stomach cancer rates are high. In the UK stomach cancer rates are much lower because these types of foods don't feature regularly in our diets.
How common is stomach cancer in Britain?
The good news is that the rate of stomach cancer in Britain has been falling since the 1930s. One reason for this fall may be that Britons have been eating less salted, smoked and pickled foods as refrigeration has become the main way of preserving food. At the moment approximately 9,700 people are diagnosed with stomach cancer each year in the UK. This is about 4% of all cases of cancer and makes it the 6th most common cancer in the UK.
Cancer of the stomach is more common in men than in women. Stomach cancers make up about 5% of all cases of cancer in men (roughly 6500 men) and 3% of all cases of cancer in women. It is also more likely to occur in later life: 9 out of 10 people diagnosed with stomach cancer are over 55.
What are the other effects of salt?
A diet high in salt is known to raise blood pressure and increases the risk of heart attack and stroke.
For more on high blood pressure, please see Bupa's High blood pressure factsheet:
http://hcd2.bupa.co.uk/fact_sheets/html/hypertension.html
How much salt does the average UK person eat?
On average a person in the UK will eat 9g salt (about 3.5g sodium) a day. While this is better than the high-risk group who ate 12-15g of salt a day, it is recommended that we should be eating no more than 6g salt (2.5g sodium) a day.
How can we work out how much salt we are getting in our foods?
All food labels give the amount of sodium the food contains and this will tell you how much salt there is.
Salt is made up of two components: sodium and chloride. Every gram of salt contains roughly 0.42 grams of sodium. So, to get a good estimate of the amount of salt in the product, we need to double the listed sodium content.
The recommended daily limit of salt is 6g, which means that we should only be eating 2.5g or less of sodium a day.
For more on food labels, please see Bupa's article "How to read a food label":
http://www.bupa.co.uk/health_information/html/healthy_living/lifestyle/diet/guide/label.html
How can we reduce the amount of salt we eat?
Dr Virginia Warren, Bupa's assistant medical director, suggests a few simple things that can be done to reduce salt intake:
- not adding extra salt to meals
- using less salt when cooking. Gradually adding less will help with the adjustment to enjoying just the natural taste of the food
- using a squeeze of lemon or small quantities of herbs and spices as an alternative to salt
- choosing fresh foods where possible, rather than the pre-prepared/pre-packed kind
- avoiding foods like crisps, bacon, soy sauce, pizza and peanuts which are all very high in salt
For more on salt, please see Bupa's article "Shake the salt habit":
http://www.bupa.co.uk/health_information/asp/healthy_living/lifestyle/diet/salt/
For more information on salt and stomach cancer, please use the links below.
Links for more information
- Bupa Shake the salt habit article
- Bupa Stomach cancer factsheet
- Cancer Research UK's stomach cancer information
- CancerBACUP's stomach cancer information
- Digestive Disorders Foundation's stomach cancer information
- CancerHelp UK's stomach cancer information
- Food Standards Agency advice on salt
- FSA - eat less salt
- FSA - salt facts
