The effects of sodium reduction and the DASH diet on ambulatory blood pressure: overall and race-stratified results from the DASH-Sodium trial.

In 30 seconds

This randomized feeding trial examined ambulatory blood pressure (ABP) responses to sodium reduction and the DASH diet in 335 participants, 58% of whom self-identified as Black. Participants followed control or DASH diets and completed three 30-day periods at different sodium levels. Compared with the high-sodium control diet, DASH with low sodium lowered awake systolic BP by 9.0 mmHg (6.4, 11.7) in Black participants and 7.5 mmHg (4.5, 10.6) in non-Black participants. Despite reductions in both groups, differences in achieved asleep BP persisted.

Key findings

• DASH with low sodium reduced awake systolic BP versus high-sodium control by 9.0 mmHg (6.4, 11.7) in Black participants and 7.5 mmHg (4.5, 10.6) in non-Black participants.
• Asleep systolic BP fell by 8.0 mmHg (4.8, 11.2) in Black participants and 7.4 mmHg (3.9,11.0) in non-Black participants with DASH and low sodium.
• On DASH with low sodium, achieved asleep systolic BP remained higher in Black than non-Black participants: 115.2 ± 0.5 mmHg versus 112.5 ± 0.7 mmHg (P < .005).
• Sodium reduction and DASH, alone or combined, significantly lowered 24-hour, awake, and asleep systolic and diastolic ABP in both racial groups.

Why it matters

The findings show that dietary approaches can lower ambulatory BP across the racial groups studied, including during sleep. However, lower BP with these interventions did not eliminate the observed difference in achieved asleep BP. This distinction is relevant when interpreting group-level responses: improvement with an intervention and convergence in final BP levels are not the same outcome.

What to keep in mind

The abstract reports results from a controlled feeding trial with 335 participants with ABP; it does not establish whether the observed BP changes persist beyond the feeding periods.