April 2, 2024 – Eating foods high in salt has long been linked to a greater risk of high blood pressure and heart disease. But much of the research into the effects of salt has been done among middle and upper income groups.
A study shows that a large proportion of low-income African Americans and white Americans exceed the current recommended sodium intake. Why then does this population get too much salt?
“In this marginalized group, it’s almost always consistent with access to food,” says Lena Beal, a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics. Lower access to healthier food means few options outside of convenience foods, a lack of education about healthier food choices and difficulty affording quality food, she said.
Salt is a necessary nutrient, but a diet with too much of this goodness has been linked to death from heart disease.
A large proportion of low-income African Americans and white Americans in the new study exceeded current recommended sodium intake, “which may have contributed to their high mortality rate from cardiovascular disease,” says senior author Xiao-Ou Shu, MD , PhD, an investigator in the Department of Medicine, Division of Epidemiology at Vanderbilt University Medical Center in Nashville. Cardiovascular disease is a term for problems with your heart and blood vessels.
About 80% of the 65,000 people in the study consumed more than the daily recommended amount of salt (or sodium) in their diet. The federal government recommends 2,300 milligrams or less per day. In contrast, black Americans consumed an average of 4,512 milligrams of sodium per day in their diet, while low-income white Americans consumed an average of 4,041 milligrams per day.
Overall, having too much sodium in their diet was linked to about 10% to 30% of cardiovascular disease deaths in the study, which was published online in the magazine on March 26 JAMA network opened.
Barriers to healthier food
“It is a solid study. We see this often in our daily practice, so it’s good to have a study that supports this,” said Beal, who was not involved in the study.
“We have our urban food deserts in Atlanta, where there is no grocery store within walking distance or a store easily accessible by public transportation, so people end up shopping at the proverbial corner store,” said Beal, a cardiac dietitian at Piedmont Atlanta Hospital .
“The barriers for this population are very real and palpable when you deal with them every day,” she said.
According to the city of Atlanta in 2015, only 52% of city residents lived within half a kilometer of fresh food, a figure that rose to 75% by 2020. The city has set a goal of increasing this to 85% by 2025.
Going forward, Beal would like to see more action. “We need to put some muscle time, energy, research dollars and resources into these communities to increase their access to wholesome, healthy choices at affordable prices.”
Excess salt, excess risk of death
Shu and colleagues examined patients an average of 14 years after entering the Southern Community Cohort Study. Between 2002 and 2009, people aged 40 to 79 participated in the study, primarily from health centers serving underserved Americans in one of the twelve southern states. They were 72% black and 28% white, and about 83% lived in households with annual incomes of less than $25,000.
After controlling for other things that can increase the risk of cardiovascular disease, the researchers found that every increase of 1,000 milligrams of salt above the recommended 2,300 milligrams per day was associated with a greater risk of death.
For example, among black patients, this added a 3% higher risk of dying from any cause, a 7% higher risk of overall cardiovascular disease, and an 8% higher risk of dying from congestive heart disease. Among white patients, the risks were even greater: an additional 8% chance of dying from total cardiovascular disease and a 13% higher risk of death from congestive heart disease. This group was also 55% more likely to die from heart failure.
And the problem isn’t just among Americans of lower socio-economic status. Americans generally consume high levels of dietary salt – an average of 3,400 milligrams per day.
Myths and possible solutions
People have several misconceptions about excess salt, Beal said. On the medical side, they tend to “misunderstand the strong correlation with heart disease, and on the nutritional side, people don’t understand how easy it is to address this.”
Avoiding excess salt doesn’t mean eating food without flavor. Instead of sprinkling the salt on top, you can add herbs and spices, Beal suggested. For example, instead of eating rice that comes in a box with a seasoning packet that you cook and serve, opt for rice in a bag that you cook and season yourself.
Shu said that “a special program aimed at educating the health risk of high sodium intake and promoting healthy diets among these vulnerable populations should be a public health priority.”
Beal encourages people to change their lifestyle in two ways, even if they are financially reluctant. “It’s about how much or how often you do something – the amount or the frequency.”
The ‘how much’ means portion control. ‘How often’ means the number of times you eat pre-packaged products, convenience foods or processed foods. Restaurant foods can also contain unknown amounts of salt, especially fast food.
Choose to buy 100% fruit drinks instead of dark sodas, Beal suggested. Opt for smaller bottles – buy an 8 ounce drink instead of 20 ounces. Buy ramen noodles and drain the liquid before eating. Additionally, limit condiments and sauces such as barbecue sauce, ketchup, and mayonnaise, which “all contain excess sodium and sugar.”
Study limitations and strengths
Shu and colleagues calculated salt in the diet based on what people once reported when they participated in the Southern Community Cohort Study. Therefore, any changes over time could not be taken into account. Also, self-reporting of dietary salt may be less accurate than testing blood or urine samples.
In terms of strengths, Beal mentioned the large sample size and focus on underserved communities.
Asked about next steps, Shu said their plans include exploring how genes influence the way sodium affects health.