According to Gram Research analysis, the DASH diet combined with low sodium significantly lowers blood pressure in both Black and White adults. A 2026 randomized controlled trial of 335 participants found that the DASH diet with low sodium reduced nighttime systolic blood pressure by 8 mmHg in Black adults and 7.4 mmHg in White adults compared to a regular diet with high salt. Despite these substantial improvements, Black participants still maintained slightly higher nighttime blood pressure than White participants even after dietary intervention, suggesting that additional strategies may be needed to fully address racial disparities in blood pressure control.
A major study tested whether the DASH diet combined with eating less salt could lower blood pressure in both Black and White adults. Researchers followed 335 people who tried different eating plans with varying salt levels. The results showed that the DASH diet with low sodium significantly reduced blood pressure during the day and while sleeping in both groups. However, Black adults still had slightly higher nighttime blood pressure than White adults even after making these dietary changes, suggesting that diet alone may not completely close this health gap.
Key Statistics
A 2026 randomized controlled trial of 335 participants published in the American Journal of Hypertension found that the DASH diet combined with low sodium reduced nighttime systolic blood pressure by 8 millimeters of mercury in Black adults and 7.4 millimeters of mercury in White adults compared to a regular diet with high salt.
According to research reviewed by Gram, the DASH diet with low sodium reduced daytime systolic blood pressure by 9 millimeters of mercury in Black participants and 7.5 millimeters of mercury in White participants, with both groups showing statistically significant improvements across all 24-hour blood pressure measurements.
The study found that despite clinically relevant blood pressure reductions from the DASH diet and sodium reduction in both racial groups, Black participants maintained a mean nighttime systolic blood pressure of 115.2 mmHg compared to 112.5 mmHg in White participants on the DASH diet with low sodium, indicating persistent racial disparities.
Research shows that combining the DASH diet with low sodium reduced 24-hour average blood pressure significantly more than either intervention alone in both Black and White adults, demonstrating that the two dietary approaches work synergistically to lower blood pressure.
The Quick Take
- What they studied: Whether eating the DASH diet (rich in fruits, vegetables, and whole grains) combined with eating less salt could lower blood pressure, especially during sleep, in both Black and White adults.
- Who participated: 335 adults participated, with 58% identifying as Black. All participants tried different eating plans over several months while researchers measured their blood pressure around the clock.
- Key finding: The DASH diet with low sodium reduced nighttime blood pressure by about 8 points in Black adults and 7 points in White adults compared to a regular diet with high salt. Both groups benefited, but Black adults still had higher nighttime blood pressure overall.
- What it means for you: If you have high blood pressure, combining the DASH diet with reducing salt intake can help lower your numbers significantly. However, Black adults may need additional strategies beyond diet to reach optimal blood pressure targets, suggesting the importance of working with healthcare providers on personalized approaches.
The Research Details
This was a carefully controlled experiment where 335 people were randomly assigned to eat either a regular control diet or the DASH diet. While on their assigned diet, each person went through three separate 30-day periods eating different amounts of salt—low, medium, and high—in random order. Researchers measured participants’ blood pressure continuously over 24 hours at the end of each period, capturing readings during waking hours and sleep.
The DASH diet focuses on eating plenty of fruits, vegetables, whole grains, lean proteins, and low-fat dairy while limiting red meat, sugar, and processed foods. This approach has been shown in previous research to help lower blood pressure. By combining it with sodium (salt) reduction, researchers wanted to see if the benefits would be even stronger.
The study was particularly important because it looked at both Black and White participants separately. Previous research has shown that Black adults tend to have higher blood pressure than White adults, especially during sleep, so understanding how different diets affect each group is crucial for improving health equity.
This research design is powerful because it controls for many factors that could affect blood pressure. By having people try all three salt levels while on the same diet, researchers could isolate the effect of salt reduction. By measuring blood pressure continuously throughout the day and night, they captured a more complete picture than just office visits. Most importantly, by analyzing results separately for Black and White participants, the study revealed that while both groups benefit from dietary changes, racial differences in blood pressure persist—a finding that could guide future treatment approaches.
This study is considered high-quality because it was a randomized controlled trial, which is the gold standard in nutrition research. Participants were randomly assigned to diets, reducing bias. The study measured actual blood pressure with devices worn continuously rather than relying on self-reporting. The sample size of 335 is substantial enough to detect real differences. However, the study only lasted 30 days per diet period, so we don’t know if benefits continue long-term. Additionally, participants knew they were being studied, which might have affected their behavior.
What the Results Show
The DASH diet combined with low sodium produced impressive reductions in blood pressure across all measurements. When comparing the DASH diet with low sodium to a regular diet with high sodium, Black participants saw their daytime systolic blood pressure (the top number) drop by 9 millimeters of mercury (mmHg), while White participants saw a 7.5 mmHg drop. During sleep, Black participants experienced an 8 mmHg reduction and White participants a 7.4 mmHg reduction.
These numbers might sound small, but they’re clinically significant. A reduction of 7-9 mmHg in blood pressure can meaningfully lower the risk of heart attack and stroke. The benefits appeared across all time periods measured—24-hour average, daytime, and nighttime—indicating that the DASH diet with low sodium works consistently throughout the day.
Interestingly, both the DASH diet alone and sodium reduction alone also lowered blood pressure compared to the control diet with high sodium, but the combination was most effective. This suggests that both dietary components contribute to the benefit, and combining them creates a stronger effect than either alone.
The study revealed an important disparity that persists even after dietary intervention. Despite the significant improvements from the DASH diet and low sodium, Black participants still had higher nighttime blood pressure than White participants. On the regular diet with high sodium, Black adults averaged 124.1 mmHg systolic pressure while sleeping, compared to 120.2 mmHg in White adults. Even on the DASH diet with low sodium—the best scenario—Black adults averaged 115.2 mmHg compared to 112.5 mmHg in White adults. This 2-3 mmHg difference during sleep persisted across all diet conditions, suggesting that factors beyond diet alone may contribute to this racial difference in blood pressure.
Previous research has shown that the DASH diet effectively lowers blood pressure in general populations, and that reducing sodium intake also helps. This study confirms those findings while adding important new information. The blood pressure reductions observed here (7-9 mmHg) are consistent with what other large studies have found. However, this research is among the first to carefully examine whether the DASH diet works equally well across racial groups and to measure the persistent disparities in nighttime blood pressure. The findings align with broader public health data showing that Black Americans experience higher rates of high blood pressure and related complications, even when receiving similar treatments.
While this study is well-designed, several limitations should be considered. First, the study only lasted 30 days per diet period, so we don’t know if these benefits continue over months or years. Second, participants knew they were being studied and had their blood pressure monitored, which might have motivated them to follow the diet more carefully than they would at home. Third, the study was conducted in a controlled feeding environment where researchers provided all the food, which doesn’t reflect real-world eating where people make their own choices. Fourth, the study doesn’t explain why racial differences in nighttime blood pressure persist despite dietary improvements—further research is needed to understand the underlying causes. Finally, the study included only adults, so results may not apply to children or teenagers.
The Bottom Line
If you have high blood pressure or want to prevent it, adopting the DASH diet combined with reducing salt intake is strongly supported by this research. The DASH diet emphasizes fruits, vegetables, whole grains, lean proteins, and low-fat dairy. Aim to limit salt to less than 2,300 mg per day, or ideally 1,500 mg if you have high blood pressure. These changes can reduce blood pressure by 7-9 mmHg, which meaningfully lowers your risk of heart disease and stroke. However, if you’re Black, you may need to work more closely with your healthcare provider to achieve optimal blood pressure targets, as dietary changes alone may not fully address racial disparities in blood pressure.
This research is most relevant for adults with high blood pressure or those at risk for developing it. The findings apply to both Black and White adults, though the study suggests Black adults may need additional support beyond diet. People with kidney disease, heart disease, or diabetes should consult their doctor before making major dietary changes. The study doesn’t provide information about children, pregnant women, or people taking certain blood pressure medications, so those groups should discuss dietary changes with their healthcare provider.
Based on this research, you can expect to see meaningful blood pressure reductions within 30 days of starting the DASH diet with reduced sodium. However, the full benefits may take longer to develop, and maintaining these changes long-term is essential. Most people notice improvements in how they feel—less fatigue, better sleep—within a few weeks. For maximum benefit, aim to stick with these dietary changes permanently rather than viewing them as temporary.
Frequently Asked Questions
How much can the DASH diet lower my blood pressure?
The DASH diet combined with low sodium can reduce nighttime blood pressure by 7-8 millimeters of mercury and daytime blood pressure by 7-9 millimeters of mercury, according to a 2026 trial of 335 participants. These reductions are clinically significant and can lower your risk of heart disease and stroke.
Does the DASH diet work the same for Black and White people?
Both Black and White adults benefit similarly from the DASH diet with reduced sodium, experiencing 7-9 mmHg blood pressure reductions. However, research shows Black adults still have slightly higher nighttime blood pressure even after these dietary changes, suggesting additional strategies may be needed for some individuals.
How much salt should I eat on the DASH diet?
The DASH diet with low sodium used in this study aimed for minimal salt intake. General recommendations suggest limiting sodium to less than 2,300 mg daily, or 1,500 mg if you have high blood pressure. Use herbs and spices instead of salt to flavor foods.
How long does it take to see blood pressure improvements from the DASH diet?
This study measured blood pressure improvements after 30 days on the DASH diet with low sodium, showing significant reductions within that timeframe. Most people notice improvements in energy and sleep quality within a few weeks of starting the diet.
Can diet alone fix high blood pressure?
The DASH diet with low sodium produces meaningful blood pressure reductions in most people, but some individuals may still need medication to reach optimal targets. This is especially true for Black adults, who may experience persistent disparities. Work with your healthcare provider to determine the best approach for your situation.
Want to Apply This Research?
- Track daily sodium intake (target under 2,300 mg) and log DASH diet compliance by recording servings of fruits, vegetables, whole grains, and lean proteins. Measure blood pressure at the same time each morning and evening to monitor trends over 30-day periods.
- Start by replacing one high-sodium processed food per day with a DASH-friendly alternative. For example, swap canned soup for homemade vegetable soup, or replace salty snacks with fresh fruit. Gradually increase servings of vegetables and whole grains while reducing salt in cooking by using herbs and spices instead.
- Use the app to track blood pressure readings weekly, noting patterns during different times of day and after dietary changes. Set reminders to check sodium content on food labels before purchasing. Create a weekly meal plan using DASH diet recipes to maintain consistency. Compare your blood pressure trends month-to-month to see if the dietary changes are working for you.
This research summary is for educational purposes and should not replace professional medical advice. The findings apply to adults with or at risk for high blood pressure, but individual results may vary. Before making significant dietary changes, especially if you take blood pressure medications, have kidney disease, or have other health conditions, consult with your healthcare provider or registered dietitian. This study was conducted in a controlled feeding environment and may not reflect real-world results. Black adults experiencing persistent high blood pressure despite dietary changes should work closely with their healthcare provider to develop a comprehensive treatment plan that may include medication and other interventions.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.