Even if your diet is healthy otherwise, it does not make up for the harmful effects of dietary sodium on blood pressure.
That’s the conclusion of a new study led by Jeremiah Stamler, M.D. of Northwestern University, Feinberg School of Medicine, and Queenie Chan, Ph.D. of the Imperial College London recently published in the American Heart Association’s journal Hypertension.
The study, under the auspices of the INTERMAP Research Group, also reaffirmed the need for widespread sodium reduction in the food supply. In the U.S., people ingest much more sodium than is physiologically necessary, in part, from eating out a lot and eating highly processed foods.
“Anything that comes in a can, package, frozen dinners, lunchmeat – if all you have to do is open it, heat it and eat it – it’s processed,” said BJC hypertension specialist and cardiologist Angela Brown, M.D.
For the INTERMAP study, researchers reviewed data on sodium intake and intake of 80 nutrients – such as proteins, fats, vitamins, minerals and amino acids – that may relate to blood pressure in 4,680 women and men participants (ages 40-59) in the United States, Japan, People’s Republic of China, and the United Kingdom. The data included sodium and potassium excretion levels in urine collections. Researchers concluded that other dietary nutrients may not offset the detrimental effects of sodium.
“Regularly consuming excessive amounts of sodium, derived mainly from commercially processed food products, is an important factor in the development of the elevated blood pressure patterns,” wrote co-lead author Jeremiah Stamler, M.D. “To prevent and control the ongoing epidemic of prehypertension and hypertension, the salt content in the food supply must be reduced significantly.”
Although some families eliminated salt shakers from their dining tables and add little to no salt when they cook at home, that is not where the biggest problem lies. About three-fourths of the sodium Americans eat comes from processed, prepackaged, and restaurant foods.
The American Heart Association recommends that adults consume no more than one teaspoon of salt (2,300 mg sodium) total per day through all the foods they eat. For African Americans, cut that number by one-third.
“The recommendation from the American Heart Association is not to exceed 1500 milligrams of sodium a day, which is hard because the culprit for sodium tends to be processed food,” said Brown, an AHA St. Louis division board member and associate professor of Medicine at Washington University St. Louis.
Reducing sodium to about 1500 mg per day is about three-fourths of a teaspoon. Other groups who should reduce sodium intake further include older adults (age 51 and older), and anyone with hypertension, diabetes, or chronic kidney disease – that would be about half of the US population.
“We’re learning more about the role other nutrients play in influencing the blood pressure-raising effects of sodium, and that the focus on sodium remains important,” said Cheryl Anderson, Ph.D., vice-chair of the American Heart Association’s Nutrition Committee. “Restaurant and prepackaged food companies must be part of the solution because Americans desire the ability to choose foods that allow them to meet their sodium reduction goals.”
The AHA nutrition committee is working with the food industry on ways to reduce sodium in the food supply. In the meantime, reading nutrition labels and awareness of high sodium products will help consumers select healthier choices for themselves and their families.
For people who are busy or who eat out a lot, paying attention to menus is important.
“Most restaurants have low sodium options on their menus,” Dr. Brown said. It also involves knowing how to interpret nutritional content on those menus. “Typically, foods that are fried are going to be saltier … foods that come with gravies or sauces also tend to be saltier as well.”
Foods that are baked or boiled or broiled, and vegetables that are steamed, are typically healthier choices. If a restaurant serves cooked to-order food, Brown said you can ask that sodium or MSG be eliminated from the meal.
“Clearly, you want to focus on a diet that is high in fruits, vegetables, low-fat dairy, but still, watching the sodium on top of that is kind of the key,” Dr. Brown said.
“You can’t get around the fact that, increased sodium by itself raises blood pressure, so if you’re at a good weight, if you are watching your fat intake, eating basically a plant-based diet, the good stuff that you are doing doesn’t outweigh increased sodium.”
More on the INTERMAP study can be found at https://tinyurl.com/yc8o4wx7.
