April 10, 2023 – It is well-known that high blood pressure is a risk factor for heart attacks and strokes.
Now, new research from Sweden has shown that too much salt in the diet is an important risk factor for clogged arteries in the neck and heart, increasing the risk of heart attacks and strokes even if you don't have high blood pressure.
The study was published online in European Heart Journal Open.
The finding raises the possibility that salt could cause damage even before someone develops high blood pressure, said study author Jonas Wuopio, MD, of the Karolinska Institutet, Huddinge, and Clinical Research Center at Uppsala University in Sweden.
Salt is bad for heart health because of its link to high blood pressure, also known as hypertension, but the role salt plays in the development of plaque in the arteries has not been examined, Wuopio said.
"Ours is the first study to examine the association between a high salt intake and hardening of the arteries in both the head and neck. The association was linear, meaning that each rise in salt intake was linked with more atherosclerosis," he said.
The study included 10,778 adults ages 50 to 64. The research team measured the amount of salt found in the their urine to estimate their salt consumption.
The researchers then captured images of the arteries of the heart to check for calcium and blockages or stenosis, and ultrasound to detect blockages in the carotid arteries in the neck.
They found that the more salt people consumed, the higher their risk of calcifications in the heart and neck arteries.
The findings were seen even after the researchers excluded people with high blood pressure.
"This means that it's not just patients with high blood pressure or heart disease who need to watch their salt intake," Wuopio said.
He tells his patients to follow guidance from the World Health Organization and other groups to limit salt to about a teaspoon a day.
"It can be hard to estimate how much salt we eat, so I advise patients to limit the use of table salt, or to replace salt with a salt substitute," he said.
Food is Medicine
The lower you can get your blood pressure, the better, said Alon Gitig, MD, an assistant professor and director of cardiology for Mount Sinai Doctors in Westchester, NY.
"Everybody knows that high blood pressure is associated with future cardiovascular disease risk, but what many don't realize is that that risk starts to increase” even at the upper end of what is considered normal. “Most of the people in the U.S. over the age of 60 have hypertension," Gitig said.
A good way to lower your blood pressure is through diet, exercise, and maintaining a healthy weight, he said.
The Dietary Approaches to Stop Hypertension (DASH) diet – which suggests several servings of fruits and vegetables a day, with few refined carbohydrates, flour, and sugar – has been shown in a study to dramatically lower blood pressure, Gitig said.
"There are two reasons for that. One is that fruits and vegetables have many phytonutrients that are good for our arteries. The other is that most of U.S. adults have insulin resistance, and insulin resistance leads to high blood pressure,” he said.
Eating more fruits and vegetables and lean meats while limiting sugar and flour will improve insulin resistance. Do that, Gitig said, “and you can bring your blood pressure down that way.”