Hypertension boosts your risk of dying of a heart attack or stroke more than smoking, high cholesterol, obesity, or any other risk factor does. And excess salt is a major cause of high blood pressure.
What’s more, salt may damage the heart, kidneys, and other organs above and beyond its effect on blood pressure. “Salt is costing us too many lives and too many dollars,” says physician Stephen Havas.
Here are five reasons why reducing salt intake is important for you—and, more importantly, the food industry.
1. Reducing salt intake means lower blood pressure
It’s no surprise that reducing salt intake lowers blood pressure. That has been shown in studies that compare higher- versus lower-salt diets in both adults and children.
One meta-analysis of 13 studies found not just lower blood pressures, but a lower risk of heart attacks, strokes, and other cardiovascular events among people who cut their salt intake.
“A decrease in sodium in the diet, even among those with only modestly elevated blood pressure, lowers risk of cardiovascular disease later in life,” says investigator Nancy Cook, an associate professor of medicine at Harvard Medical School.
2. You will probably get high blood pressure if you don’t have it now
Why worry about reducing salt intake if you haven’t been diagnosed with high blood pressure? Odds are, you will be.
“Over time, 90 percent of people in this country develop hypertension,” says Havas, a former Vice President of Science, Quality, and Public Health at the American Medical Association.
That’s because—unless you live in a society where people eat very little salt—blood pressure rises as you age. In the Atherosclerosis Risk in Communities study, which followed more than 15,000 Americans aged 45 to 64, average systolic blood pressure (the upper number) jumped five points in five years.
“Blood pressures drift upward as people get older and they’re exposed to long-term excess sodium,” explains Havas. “That’s why almost all adults are going to get blood pressures that put them at higher risk for heart disease and stroke.”
3. Risk rises before your blood pressure is high
Doctors consider prescribing drugs when your blood pressure is high—that is, it’s at least 140 over 90. But it’s a threat to your blood vessels before it crosses that line.
“People don’t realize that blood pressure higher than 120 over 80 is associated with increased risk,” says Havas.
“Between ‘normal’ and ‘hypertension’ you have a huge number of heart disease and stroke deaths attributable to excess blood pressure,” he explains.
The National Heart, Lung, and Blood Institute (NHLBI) calls those in-between blood pressures “pre-hypertension.” Roughly one out of three American adults has it. Another one out of three has hypertension.
Researchers aren’t sure how elevated blood pressure raises the risk of heart attacks and strokes. One possibility: it may accelerate the clogging of arteries.
4. Hypertension harms the heart, brain, and kidneys
High blood pressure doesn’t just raise the risk of heart attacks and strokes. It also boosts the risk of heart failure, which affects 5.8 million Americans.
“It can mean that the heart’s pump has deteriorated and can’t push the blood out,” says Norman Kaplan of the University of Texas Southwestern Medical Center in Dallas.
And high blood pressure is a leading cause of chronic kidney disease, which strikes one out of nine Americans. Also troubling is the growing evidence that hypertension raises the risk of dementia.
For example, in the Women’s Health Initiative Memory Study, which took MRI brain scans of 1,400 women over age 65, those with high blood pressure had more abnormal brain lesions eight years later.
“Even moderately elevated blood pressure is associated with silent vascular disease in the brain that contributes to risk of dementia,” conclude the study’s authors.
5. Drugs haven’t solved the problem
So what if you get high blood pressure? Can’t you just take a drug to lower it?
“You don’t want to wait until your blood pressure crosses that magic threshold of 140 over 90 because by that point you’ve already done a fair amount of damage to your heart, vascular system, kidneys, and brain,” says Havas.
What’s more, 42 million Americans have uncontrolled hypertension. That’s because 28 percent of those who have hypertension don’t know it, 11 percent know they have it but aren’t being treated, and 26 percent are being treated but not enough to get their blood pressure below 140 over 90. That means 65 percent of Americans with hypertension don’t have their blood pressure under control.
Why? “Hypertension is a chronic condition that doesn’t make the patient feel anything,” explains Kaplan. “If people with, say, rheumatoid arthritis don’t take their medication, they hurt. So they’ll take that medication. But people with hypertension don’t experience anything obvious.” So they stop.
Sources: books.nap.edu/openbook.php?record_id=12819. 2 J. Human Hypertens. 16: 761, 2002. Hypertension 48: 861, 2006. BMJ 339: b4567, 2009. BMJ 334: 885, 2007. Circulation 106: 703, 2002. J. Clin. Hypertens. 12: 203, 2010. 8 N. Engl. J. Med. 361: 878, 2009