Reviewed by Dietitian Jessica Ball, M.S., RD
Design elements: Getty Images. EatingWell design.
Key Points
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High blood pressure is common in U.S. adults, many of whom don’t know they have it.
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Eating less sodium and more potassium may help reduce your risk of hypertension.
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Eat more fruits, vegetables, nuts, legumes and salmon to increase your potassium intake.
Blood pressure is a vital function in our bodies that helps circulate blood. A blood pressure reading measures the amount of pressure inside the arteries, the blood vessels that carry blood away from your heart to the rest of the body. When blood pressure is consistently high—over 130/80—it becomes a risk factor for heart disease and stroke.
Hypertension (high blood pressure) is called the silent killer because it typically has no symptoms. In 2023, high blood pressure was a primary or contributing cause of 664,470 deaths in the United States. It’s estimated that at least 50% of U.S. adults have hypertension, though many don’t even know they have it; the only way to really know if you have it is to get it checked regularly.
While genetics can play a role in blood pressure, lifestyle has a strong influence, too. A lack of consistent physical activity, stress, alcohol and smoking all have negative effects on blood pressure. Another area is diet.
For example, sodium is a necessary nutrient that helps regulate fluid balance in our bodies. But when consumed in excess, sodium may increase the risk of high blood pressure. Scientists have discovered, however, that sodium doesn’t stand alone as the culprit. Potassium counteracts sodium by helping excess sodium exit the body, so it’s really more about the potassium-sodium ratio.
It’s this ratio, which can be measured in urine, that Japanese researchers recently studied regarding its connection with blood pressure. They published their findings in the journal Nutrients. Let’s break down what they found.
How Was This Study Conducted?
This was an original study conducted in Japan at a large company that had two cafeterias that served lunch. The study included 166 participants (102 men and 64 women with an average age of 44) who were company employees and regularly ate lunch in one of the two cafeterias.
The study was divided into two four-week periods—an intervention period and a control period. Half the group participated in the intervention period first and then the control, and half did the control period first and then the intervention.
During the intervention period, participants were served foods with low-sodium, high-potassium seasonings—including a salt substitute that contained 75% sodium chloride and 25% potassium chloride. Because this was a Japanese study, the foods were common in Japanese culture, including miso soup and noodles.
Though dairy is not as common in Japanese culture, it is convenient and a good source of potassium. For this reason, the cafeterias were stocked with milk and yogurt during the intervention period, and participants were instructed to choose one dairy product for each workday lunch in addition to choosing a low-sodium, high-potassium menu item. For other meals—breakfast and dinner—and weekends, participants were instructed to eat their usual foods with no restrictions. This principle also applied to all meals during the four-week control period.
Beyond sex and age, minimal data were collected at baseline and throughout the study period. These included body-mass index (BMI), blood pressure, urine sodium and potassium levels and which cafeteria meals were consumed. Participants also revealed whether they were current, past or never smokers, what their typical dairy intake was, whether they were currently following a low-salt diet and whether they were on medication for high blood pressure.
What Did This Study Find?
Researchers found that after the intervention period, which included the low-sodium, high-potassium lunches, participants’ sodium-potassium ratios were more favorable, with urinary sodium being lower and potassium significantly higher. This matters because an unbalanced sodium-potassium ratio has been linked to an increased risk of hypertension.
Ironically, however, participants did not experience a reduction in blood pressure in this study. Researchers note that this may be due to one of the many limitations of this study, starting with having no washout period between the two experiments (intervention and control). Typically, when two conditions are being tested back-to-back—in this case, the intervention and control periods—there is a washout period to “wash out” the previous conditions’ results, typically lasting two or more weeks.
Researchers also note that this study was small and short, and that participants may have experienced a reduction in blood pressure had there been more participants for a longer period. They may also have experienced more benefits had the majority of their meals focused on reducing sodium and increasing potassium, instead of just weekday lunches. It’s also important to note that most of the participants’ blood pressures were in the normal range at baseline, which may also explain why there was no reduction in blood pressure at the end of the study.
How Does This Apply to Real Life?
This study suggests that reducing sodium and increasing potassium intake through seasonings and dairy may have a positive effect on your sodium-potassium ratio, which has been linked to blood pressure.
Potassium-rich foods go beyond just dairy. Consider also adding more fruits, vegetables, nuts, legumes and salmon to your line-up. Leafy greens, bananas, potatoes, avocados, sweet potatoes, squash, carrots and tomatoes are some of the fruits and veggies highest in potassium.
While too much salt, which contains sodium, may increase blood pressure, it also helps enhance the flavor of foods. Progressively reducing salt in recipes and at the table will help your body adjust to the less salty flavor over time. Experiment with using herbs and spices as you reduce salt to increase the flavor quotient. Some of them, including cinnamon, turmeric and oregano, may even help lower blood pressure.
If you’re ready to go all-in on a healthy blood pressure diet, then you’ll want to check out the DASH (Dietary Approaches to Stop Hypertension) diet. And it just so happens that we’ve got a delicious 30-Day DASH Diet Meal Plan for Beginners to get you started. It’s low in sodium, rich in potassium and high in flavor. Or if you just want some DASH diet dinner ideas, we’ve got a month’s worth of them for you.
Remember that while sodium-potassium balance is important for healthy blood pressure, other lifestyle habits matter, too. Moving your body more often throughout the day is a great habit to establish for healthy blood pressure. Chronic stress increases blood pressure, as does poor sleep, so it’s important to pay attention to both of these areas, too. If you smoke, get help to quit, and limiting or avoiding alcohol will also help cultivate healthy blood pressure.
Our Expert Take
This study suggests that by eating a lower-sodium lunch that’s rich in potassium, you may favorably balance your sodium-potassium ratio. And while the participants in this study didn’t show a change in blood pressure, had they applied the low-sodium, high-potassium principle to more meals and for longer, the benefits may have extended to blood pressure.
Start reducing the amount of salt you add to recipes and at the table, limit ultra-processed foods, like processed meats, which tend to be high in sodium. Also, limit how often you eat out, since restaurants are known for adding a considerable amount of salt to their fare. Consume more foods rich in potassium, including dairy, fruits, vegetables, nuts and legumes, which also provide a wealth of other essential nutrients for healthy blood pressure and overall good health.
Read the original article on EatingWell