What the DASH Diet Meta-Analyses Actually Show

The DASH (Dietary Approaches to Stop Hypertension) diet emphasizes potassium, magnesium, calcium, and fiber (via fruits, vegetables, whole grains, low-fat dairy) while limiting sodium and saturated fat — a combination that supports vascular function and counters sodium's blood-pressure-raising effects through multiple simultaneous mechanisms rather than one single compound.

The 2025 numbers

A 2025 systematic review and meta-analysis found the DASH diet reduced systolic blood pressure by 1.29-4.6 mmHg and diastolic by 0.76-1.1 mmHg across trials.¹ An earlier but larger meta-analysis (30 RCTs, 5,545 participants) found reductions of 3.2 mmHg systolic and 2.5 mmHg diastolic on average.²

Where the biggest effect showed up

The low-sodium version of DASH specifically produced considerably larger drops: 7.1 mmHg systolic in people without hypertension, and 11.5 mmHg in people who already had hypertension.

Why sodium reduction changes the math

The sodium-restriction component appears to meaningfully amplify DASH's effect — the diet pattern alone helps, but pairing it with active sodium reduction produced the largest blood pressure changes in the trials, especially for people already hypertensive.

The practical takeaway

• DASH's effect is real but modest on its own — sodium reduction is what amplifies it
• People already hypertensive saw the largest benefit from the combined approach
• This is not a substitute for prescribed blood pressure medication — talk to a doctor about combining the two