Health experts and industry groups are clashing over national sodium standards ahead of a fall congressional debate over first lady Michelle Obama’s signature school lunch regulations.
Groups including the Salt Institute contend that the federal government is years behind in its research on sodium consumption and that some studies have shown getting too little could be more dangerous than getting too much.
{mosads}“There is absolutely no scientific basis for any population-wide sodium reduction strategy,” said the group’s president, Lori Roman. “Studies show, left to ourselves, we will naturally seek out the safe range. What I worry about is the captive people — the kids in schools, who are getting more than one meal a day or maybe one of their only meals of the day, and elderly people in nursing homes, who are put on low-sodium diets for no reason.”
Under the Healthy Hunger-Free Kids Act, which is up for reauthorization this month, schools are required to reduce sodium levels in the coming years.
The rules would reduce per-lunch maximum sodium levels from 1,230 milligrams in elementary school, 1,360 mg in middle school and 1,420 in high school to 935, 1,035 and 1,080, respectively, by 2017. They would be lowered again to 640, 710 and 740 by 2022.
With these standards, Roman said, kids eating both their breakfast and lunch at school are less likely to perform as well as they should.
“Low-sodium diets are very dangerous, especially for athletes, because sodium is the most important electrolyte we have,” she said. “There’s a reason why athletes many years ago took sodium tablets and now tend to drink Gatorade.”
The U.S. Department of Agriculture (USDA) said sodium levels for lunch are designed to be a third of what students should be consuming daily.
The 2010 Dietary Guidelines for Americans recommends that everyone age 2 and up consume less than 2,300 mg of sodium a day, a standard the federally appointed panel of nutritionists decided to keep in making its recommendations for the new 2015 guidelines the USDA and the Department Health and Human Services are due to finalize this fall.
Recent studies, however, have raised questions about whether people should actually be getting more than the recommended 2,300 mg a day.
In two global studies published in “The New England Journal of Medicine” last year, professors at McMaster University in Ontario, Canada, took urine samples from of 100,0000 people across 18 countries and found there is “sweet spot” for sodium consumption between 3,000 and 6,000 mg a day.
Andrew Mente, who served as lead author on the first study, found diminishing returns in health benefits for people who lower sodium intake to improve their blood pressure. Mente also looked at how feasible it would be to get people around the world to eat only 2,300 mg of sodium a day.
“When we adjust for error, we found that no one consumed less than 2,300 mg,” he said.
The second study, led by Martin O’Donnell, showed an increased risk for cardiovascular problems among people who ate more than 6,000 to 7,000 mg a day and also an increased risk among people who ate less than 2,000 to 3,000 mg a day.
“We’re eating what we’re supposed to be eating as far as sodium is concerned,” Mente said. “In nutrition, we never learn from history. We make recommendations without having the proper science to justify those recommendations.”
Dr. Lawrence Appel, a professor of medicine at Johns Hopkins University and the director of the Welch Center for Prevention, Epidemiology and Clinical Research, however, dismissed the Canadian studies.
“There are a lot of fairly technical issues that make it hard to study sodium and subsequent disease,” he said. “That’s why we do randomized feeding studies. Studies relating to spot urine are really problematic.”
Despite what people may think, Appel said, problems with hypertension begin early in life.
“The perception is that blood pressure is a problem we wait and manage when we’re in our 50s and 60s,” he said. “Elevated blood pressure leads to a sickening of the heart and change in blood vessels. Seeing it in early adolescents points to a consistent belief among hypertension researchers that keeping blood pressure as low as we can for as long as possible is how we are going top prevent cardiovascular disease in our country.”
According to the Centers for Disease Control and Prevention, 9 in 10 U.S. children eat more sodium than is recommended, and 1 in 6 children between the ages of 8 and 17 have high blood pressure.
The School Nutrition Association (SNA), which represents school districts around the country, said the final sodium reductions set by the Obama administration, however, are virtually impossible to meet.
“Schools are committed to reducing the sodium in school meals and snacks, but the later sodium reduction mandates are unrealistic for schools, let alone families, and will force healthy choices off the menu,” SNA President Jean Ronnei said in a statement to The Hill.
The group has called on Congress to leave sodium levels where they are until there’s scientific evidence to prove further reductions would benefit children’s health.
There appears to be some interest among GOP members to relax the rules for sodium, along with other provisions of the law such as what percentage of grains served should be whole grain rich. Sen. John Hoeven (R-N.D.) has introduced a bill that would prevent the USDA from requiring sodium reductions in school meals below the current level, which took effect in July 2014. Senate Agriculture, Nutrition and Forestry Committee Chairman Pat Roberts (R-Kan.) is working to finish a reauthorization package in time for a committee markup on Thursday.
But Agriculture Secretary Tom Vilsack said the research linking excessive sodium to heart disease has already been affirmed and will likely be reaffirmed in the future.
“The reality is over time we can get to a place where those sodium levels are less than they are today,” he said during an event at the National Press Club last week. “We obviously will abide by the congressional direction, but I think what we will see over time is there is not going to be a step back in sodium reduction in terms of appropriate health outcomes.”