High Salt Intake Linked to Increased Gastric Cancer Risk

Gastric Cancer, which is also known as stomach cancer, is the fifth most common cancer worldwide. While not as common in the United States, it still makes up about 1.5% of new cancer cases diagnosed annually. Physicians today want to identify the risks associated with this cancer type so that they can increase the survival rates. 

A recent study published in Gastric Cancer examined data from over 470,000 individuals to see how the frequency of adding salt to food related to cases of gastric cancer. It was found that participants who always consumed extra salt to their food were at a higher risk for gastric cancer compared to participants who rarely added the substance. This study adds to data about the risk salt poses for gastric cancer in non-asian populations, as most research in this area has been in Asian populations. 

As research moves forward, doctors may be able to ask people about their frequency of adding salt to foods as a simple indicator to monitor salt intake and related gastric cancer risk, aiding public health messaging. 

Data of 471,144 participants were used in this study where people who did not submit data on their body mass index, salt intake and urinary sodium levels were excluded from the study. Participants with borderline cancer were also excluded. Urinary sodium intake, creatinine and potassium levels of the participants who were included in the study were checked. Participants filled out baseline questionnaires to indicate how often they added salt to food, excluding the salt they used while cooking. Participants could respond with never/rarely, sometimes, usually, or always. Researchers further measured participants’ urinary sodium, creatinine, and potassium levels. They were also able to estimate 24-hour urinary sodium excretion. 

This study took into account physical activity levels, age, education levels, ethnicity, sex and alcohol consumption. Red meat along with fruit and vegetable intake daily were also checked. The average follow-up period with participants was 10.9 years. 

During the follow-up time, 640 cases of gastric cancer among participants were documented. In general, participants who reported always adding salt to food at the table were more likely to be past or current smokers, have a high level of alcohol intake, and have a lower education level. Researchers found that participants who always added salt at the table were at 41% higher risk for gastric cancer compared to participants who never or rarely added salt to food at the table. 

While they found that adding salt to food more often was associated with increased 24-hour urinary sodium levels, they did not find a significant association between 24-hour urinary sodium levels and gastric cancer. 

They also found that in a subset of 198,900 participants, responses to the frequency of adding salt to the table positively correlated with daily sodium intake levels. After careful analysis, it was found that participants who always added salt during meal consumption were at a 41% higher risk for gastric cancer. Gastric cancer is very serious especially if it is present at an advanced stage. Also, the pattern of presentation is different with patients from Western countries presenting more often with cancer in the upper part of the stomach, a more challenging location to manage than in Asian countries where cancers are more often found in the lower part of the stomach. This may be related to a higher incidence of obesity and gastroesophageal reflux disease in Western countries — risk factors for upper gastric cancer.