Less Salt for a Healthier Heart

High salt intake linked to increased blood pressure and heart problems

Most Americans eat more salt than government dietary guidelines recommend. Research suggests it may be unwise to eat so much salt, as it might be harmful to your health.

A recent report reviewed existing studies on salt intake to see if an excess of dietary salt caused health problems. The report also examined the effects of potassium intake.

The report revealed that high salt consumption was not only strongly linked to high blood pressure, but to heart and kidney problems as well. However, it also showed that increasing potassium intake may help fight back against the negative effects of salt.

The authors of this report concluded that doctors and federal health agencies should continue to emphasize the importance of limiting salt intake.

"Limit the amount of salt that you eat."

Kristal Aaron, BS, MSPH, and Paul Sanders, MD, both of the Department of Medicine/Nephrology at the University of Alabama at Birmingham, put this report together in order to provide a more thorough resource on dietary salt and potassium.

Many previous studies have shown an association between table salt (sodium chloride) intake and hypertension, or high blood pressure. High blood pressure can cause a number of health problems, including heart attack and stroke.

The US Department of Health and Human Services and the US Department of Agriculture have said that individuals should eat no more than 2,300 milligrams of sodium per day. For some populations, they have advised 1,500 milligrams per day. However, between 2003 and 2008, the average daily sodium intake per person age 20 and up in America was about 3,371 milligrams.

Yet other evidence has shown that increased salt intake may not be as harmful as previously thought. Some have even recommended less strict salt guidelines.

To help resolve the debate, the authors of this report looked at clinical trials that evaluated dietary salt and potassium and their effect on blood pressure, heart disease rates and death rates. Each of the studies was published between 1990 and 2013.

Altogether, the authors looked at 52 studies. Twenty-eight of the studies involved changing the amount of dietary salt eaten, 12 changed the amount of dietary potassium and 12 involved changing both.

In the studies on dietary salt intake, a total of 4,019 people changed their salt intake (received intervention) and 3,714 people served as comparisons (control group). In the potassium studies, 2,713 participants received an intervention and 2,430 served as comparisons.

The clinical trials recorded data on the participants' blood pressure over time and various signs of heart and kidney disease. 

The studies showed that high salt intake elevated blood pressure and also did damage to organs like the kidney and heart.

However, potassium intake tended to lessen the unhealthy effects of salt intake. In the clinical trials testing potassium intake, people who consumed more potassium had decreased stroke and heart disease rates.

The authors found that certain populations, like those who were overweight or aging, may benefit the most from reducing their salt intake, as these groups were particularly sensitive to lessening their salt consumption.

The authors concluded that most people could benefit from a modest restriction of the salt they consume and from increasing potassium consumption. They also said that some populations with existing health conditions should consult with their healthcare professionals in case they need a specialized dietary plan.

This study was published in Mayo Clinic Proceedings in September.

The researchers disclosed no conflicts of interest. Dr. Sanders was supported by grants from the Nephrology Research and Training Center at the University of Alabama at Birmingham and other research organizations.

Review Date: 
September 13, 2013