Researchers looked at what over 5,500 American adults ate and checked if the amount of salt and potassium in their diets affected their blood pressure. Surprisingly, they found that eating more or less salt and potassium didn’t seem to make a big difference in whether people had high blood pressure. This challenges what many doctors have believed for years. The study used information from a large national health survey, making it a good snapshot of what’s happening across the country. However, the researchers note that how all the foods work together might matter more than just looking at salt and potassium alone.

The Quick Take

  • What they studied: Whether eating different amounts of salt and potassium affects a person’s chances of having high blood pressure
  • Who participated: 5,569 American adults aged 20 and older who participated in a national health survey in 2017-2018. The group included people of different ages, weights, and backgrounds.
  • Key finding: Eating more or less salt and potassium did not appear to change the risk of having high blood pressure. The results were the same whether researchers looked at salt alone, potassium alone, or the balance between them.
  • What it means for you: While salt reduction is still generally recommended for heart health, this study suggests that simply cutting salt or adding potassium alone may not be the main answer to preventing high blood pressure. Your overall eating patterns and lifestyle choices may matter more than focusing on just these two minerals.

The Research Details

This was a cross-sectional study, which is like taking a snapshot in time. Researchers looked at data from 5,569 adults who participated in the National Health and Nutrition Examination Survey (NHANES) in 2017-2018. Each person reported everything they ate in a single 24-hour period, and researchers used this information to calculate how much salt and potassium they consumed. The researchers also asked people whether they had been diagnosed with high blood pressure by a doctor. They then used statistical tools to see if there was a connection between what people ate and whether they had high blood pressure, while accounting for other factors like age, weight, exercise, and overall diet quality.

This approach is important because it uses real-world data from a large, representative group of Americans rather than a small group in a lab setting. This makes the findings more likely to apply to the general population. The researchers also looked at whether the relationship between salt/potassium and blood pressure was different for different groups of people (like older adults versus younger adults, or people with obesity versus people at a healthy weight).

This study has several strengths: it included a large, nationally representative sample of Americans, used standardized methods to measure diet and blood pressure, and adjusted for many other factors that could affect the results. However, the study only captured one day of eating, which may not represent a person’s typical diet. Also, people self-reported their blood pressure diagnosis, which could be less accurate than direct measurements. The study shows an association (or lack of one) at one point in time, but cannot prove that salt or potassium causes or prevents high blood pressure.

What the Results Show

The main finding was surprising: after accounting for other factors like age, weight, physical activity, and overall diet quality, eating more salt did not increase the risk of high blood pressure, and eating more potassium did not decrease the risk. The statistical measures showed results very close to 1.0, meaning no meaningful difference. This held true whether researchers looked at salt and potassium separately or examined the ratio between them. The findings remained consistent even when researchers used different statistical methods to double-check their results. When researchers looked at whether the relationship changed depending on the shape of the data (using a technique called spline analysis), they still found no clear pattern.

The study did find a weak trend suggesting that eating more fiber might be associated with slightly lower blood pressure risk, though this was not statistically significant. When researchers looked at specific groups, they noticed slightly stronger (but still not statistically significant) associations between sodium/potassium and blood pressure in older adults and people with obesity. However, these differences were not strong enough to be considered reliable findings.

This finding is interesting because many previous studies and health guidelines have recommended reducing salt intake to lower blood pressure. Some large studies have shown benefits from salt reduction, while others have shown mixed results. This new study adds to the debate by suggesting that the relationship between salt, potassium, and blood pressure may be more complicated than previously thought. The researchers emphasize that looking at individual nutrients in isolation may not tell the whole story—the overall pattern of eating and individual differences between people may be more important.

This study has important limitations to consider. First, it only measured what people ate on a single day, which may not represent their typical eating habits. Second, people reported whether they had high blood pressure based on a doctor’s diagnosis, rather than having their blood pressure directly measured by researchers. Third, this type of study can only show whether two things are related at one point in time; it cannot prove that one causes the other. Fourth, the study relied on people’s memory of what they ate, which can be inaccurate. Finally, the study couldn’t account for all possible factors that might affect blood pressure, such as stress, sleep, or medications people were taking.

The Bottom Line

Based on this study alone, you should not change your approach to salt and potassium intake. However, this research should be considered alongside other evidence. General health organizations still recommend moderate salt intake and adequate potassium as part of a heart-healthy diet, though this study suggests these individual changes may not be the primary way to prevent high blood pressure. Focus on overall healthy eating patterns, regular physical activity, maintaining a healthy weight, and managing stress. If you have high blood pressure, work with your doctor on a comprehensive approach rather than focusing only on salt or potassium. Confidence level: Moderate—this is one study that contradicts some previous findings, so more research is needed.

This research is relevant to anyone interested in preventing high blood pressure, particularly adults aged 20 and older. It’s especially important for people who have been told to strictly limit salt intake. However, people with certain kidney conditions or those taking specific medications should still follow their doctor’s advice about salt and potassium, as this study doesn’t apply to everyone. This study should not be used to ignore other proven ways to lower blood pressure, such as exercise, weight management, and stress reduction.

If you were to make changes based on this research, you wouldn’t expect to see changes in blood pressure overnight. Blood pressure typically takes several weeks to months to change in response to dietary modifications. However, this study suggests that salt and potassium changes alone may not be the most effective approach, so you might not see significant changes even with long-term modifications to these nutrients alone.

Want to Apply This Research?

  • Track your overall dietary pattern rather than obsessing over salt and potassium alone. Log your daily meals and note your blood pressure readings weekly (if you have a home monitor). Look for patterns between your overall eating quality and blood pressure trends over 4-8 weeks.
  • Instead of just reducing salt, focus on eating more whole foods (fruits, vegetables, whole grains, lean proteins) and fewer processed foods. Use the app to set a goal of adding one new vegetable or fruit to your diet each week, which naturally increases potassium and fiber while improving overall diet quality.
  • Use the app to track your overall diet quality score rather than individual nutrients. Monitor blood pressure weekly if possible, and look for correlations with your overall eating patterns, physical activity, sleep, and stress levels over 8-12 weeks. Share these patterns with your doctor to develop a personalized approach.

This study presents findings from a single cross-sectional analysis and should not be used to replace medical advice from your healthcare provider. If you have been diagnosed with high blood pressure or have a family history of heart disease, continue following your doctor’s recommendations regarding diet and medication. This research suggests the relationship between salt, potassium, and blood pressure is complex, but does not mean you should ignore general heart-healthy eating guidelines. Always consult with your healthcare provider or a registered dietitian before making significant changes to your diet, especially if you have kidney disease, heart conditions, or take medications that affect electrolyte balance. This study applies to the general adult population and may not apply to individuals with specific medical conditions.