Reducing daily salt intake by about one teaspoon may be as effective in lowering blood pressure as common hypertension drugs.
An average American consumes over 3,400 mg of sodium each day, exceeding the ideal limit of no more than 1,500 mg for most adults set by the American Heart Association.
Too much sodium in the diet can increase blood pressure, which is a risk factor for heart disease and stroke.
A new study from Vanderbilt University Medical Center, Northwestern Medicine, and the University of Alabama at Birmingham published in JAMA Network suggests that cutting daily salt intake by one teaspoon may significantly reduce blood pressure.
The study included 213 participants aged 50 to 75 years. Of those, one-quarter had normal blood pressure, and the rest had hypertension.
The participants were randomized to either a high-sodium diet (2,200 mg per day on top of their usual diet) or a low-sodium diet (500 mg in total per day) for one week. Then, they followed the opposite diet for another week.
A low-sodium diet reduced systolic blood pressure (the upper number) by 7 to 8 mm Hg compared with a high-sodium diet and by 6 mm Hg compared with the participants' usual diet. The reduction is comparable to the effect produced by a commonly utilized first-line medication for hypertension.
Overall, 72% of participants experienced a lowering of their systolic blood pressure on the low-sodium diet compared with their usual diet, regardless of whether they already were on blood pressure medications.
"The effect of reduction in dietary sodium on blood pressure lowering was consistent across nearly all individuals, including those with normal blood pressure, high blood pressure, treated blood pressure, and untreated blood pressure," said Dr. Deepak Gupta, M.D., MSCI, associate professor of Medicine at VUMC and co-principal investigator.
How to lower the salt intake
Most sodium is consumed with packaged and restaurant food as a result of food processing. Therefore, people are often unaware of how much salt they are consuming. One teaspoon of salt contains 2,300 mg of sodium, way above the recommended limit.
According to the Centers for Disease Control and Prevention, more than 40% of the sodium Americans eat daily comes from these 10 foods: pizza, sandwiches, deli meats, soups, cheese, tacos and burritos, potato chips, fried chicken, scrambled eggs and omelets, and bread and rolls.
"Just as any physical activity is better than none for most people; any sodium reduction from the current usual diet is likely better than none for most people with regards to blood pressure," said Gupta.
You can reduce sodium in your diet by taking these five steps:
- Choose fresh foods over salty, processed foods. Eat more fruits and vegetables. Skip or limit frozen meals. Avoid cuts of meat that are marinated, canned, smoked, brined, or cured.
- Limit or cut salty meats like bacon, ham, and deli meats.
- Look for sodium-free or low-sodium foods. Choose "low," "reduced-sodium," or "no-salt-added" versions of foods.
- Replace salt or salty seasonings with herbs and spices, as well as spices, lemon, lime, vinegar, or salt-free seasoning blendings.
- Limit the condiments, "fixins," and side dishes, such as salad dressings, ketchup, barbecue sauce and hot sauce, pickled vegetables, olives, and sauerkraut.
While reducing the salt intake by about one teaspoon a day can be as effective as common hypertension drugs, do not discontinue your medications without consulting your health provider.
- JAMA Network. Effect of Dietary Sodium on Blood Pressure.
- Vanderbilt University Medical Center. Most can lower blood pressure by reducing salt, even those on BP drugs: study.
- National Heart, Lung, and Blood Institute. Halt the Salt: 5 Ways to Cut Down on Sodium and Improve Your Heart Health.
- American Heart Association. How much sodium should I eat per day?