It’s well known that adding salt regularly to your food raises the risk of hypertension and the resultant risks of heart attacks and strokes. But now, researchers in New Orleans have found that it also significantly increases the danger of triggering chronic kidney disease.
People can get excess salt also from preserved and other foods like pickles and luncheon and cured meats including processed turkey or chicken, bologna, salami, corned beef, pastrami, liverwurst, frankfurters, sausages, dried meat and dried fish.
Dr. Lu Qi of Tulane University in Louisiana and colleagues studied the records of 465,000 people who were asked how often then added sodium to foods – usually at the table. The self-reported frequency of adding salt to foods was found to be linked to a higher risk of lifelong kidney disease that could be minimized by keeping the salt shaker out of reach.
“To our knowledge, this is the first study indicating that higher self-reported frequency of adding salt to foods is associated with a higher chronic kidney disease risk in the general population,” they wrote. It was published in the journal JAMA Network under the title “Self-Reported Frequency of Adding Salt to Food and Risk of Incident Chronic Kidney Disease.”
“The self-reported frequency of adding salt to foods could reflect a person’s long-term salt taste preference, and salt intake has been associated with increased risk of cardiovascular diseases. Whether self-reported adding of salt to foods is associated with increased risk of chronic kidney disease remained unknown.”
Who was part of the study's overall sample?
The team studied people aged 37 to 73 included in the UK Biobank of health data. Participants were enrolled from 2006 to 2010 and prospectively followed up for disease diagnosis. Participants were asked if they added salt to their food never or rarely, sometimes, usually, or always.
They were checked for a number of potential confounders including age, sex, race and ethnicity, estimated glomerular filtration rate (eGFR) by the kidneys, body mass index (BMI), smoking status, alcohol drinking status, regular physical activity, high cholesterol, diabetes, cardiovascular disease, infectious disease, immune disease, and drugs that could interfere with kidney function.
Those with higher self-reported frequency of adding salt to foods were more likely to have a higher BMI and a lower eGFR – a measure of how well your kidneys are working. Those who added salt to their foods were also more likely than those who did not add salt to their foods to be current smokers and have diabetes or cardiovascular disease. In addition, having a lower BMI and regular physical activity significantly lowered the risk of chronic kidney failure.
The team concluded that “reducing the frequency of adding salt to foods at the table might be a valuable strategy to lower lifelong kidney disease risk in the general population.”