The world has an increasingly high taste for salty foods — a taste that new research suggests leads to to 1.65 million excess deaths annually.
The massive study, overseen by 10 researchers working in Boston and London, brought together two important data points. First, they looked at what we know from prior studies of how much salt increases the risk of death from heart disease. Then they looked at how much salt each country is consuming.
Pulling those two data sets together, they found that too much salt consumption kills more than a million people each year, with death rates the highest in low- and middle income countries.
Another way to put it: too much salt intake now accounts for one of every ten deaths from cardiovascular causes.
We're consuming nearly twice as much sodium as recommended
The World Health Organization recommends consuming no more than 2 grams of sodium daily. (That works out to about 5 grams of salt, which is a compound of sodium and chloride.) The WHO set this level using research about how much sodium consumption can lead to risk of heart disease or death.
Using urine samples taken from 1.38 million people across the globe, the researchers in this study found that the average person now consumes 3.95 grams of sodium daily, nearly twice the recommended amount. High consumption is pretty much an international norm: 181 of the 189 countries studies exceeded the recommended intake.
More sodium intake means more deaths
There is a lengthy body of research tying higher sodium intake to higher blood pressure — and then, in turn, tying that to higher rates of death from cardiovascular events, like heart attacks and strokes.
The researchers here used those estimates to extrapolate out how many deaths the world's increased taste for salt causes. Their study was published in the New England Journal of Medicine.
"On the basis of the correlations between sodium intake and blood pressure and between blood pressure and cardiovascular mortality," they wrote, "we found that 1.65 million deaths from cardiovascular causes worldwide in 2010 were attributable to sodium consumption."
Those deaths span the globe, as you can see in the map below.
The rate of deaths due to excessive sodium consumption is especially high in Central Asia and Eastern and Central Europe (the areas that are red in the map above). The country with the highest rate of death from too much sodium is Georgia, where the researchers estimate that, for every 1 million residents, excess salt kills 1,967 annually.
Many of these deaths occur in non-elderly populations: the paper estimates that, of deaths caused by excess sodium intake, 40 percent happen to people younger than 70. And the vast majority of deaths — four out of every five — happen in low to middle income countries.
No fast fix in sight
Over the past 40 years, the percent of Americans who consume more sodium than recommended has gone up.
There is some evidence though that our taste for salt may be plateauing: survey data from 2003 through 2010 showed no change in the number of Americans who consume too much salt.
It's fair to think of that as less-bad news: there doesn't seem to be an increase in the percent of Americans consuming too much salt, but most people already have higher than recommended intake.
Correction: an initial version of this story misstated the average sodium intake as salt intake. The average sodium intake found in this study was 3.95 grams per day.