Baseline Blood Pressure and Sodium Intake
Starting point captured before any dietary change begins.
- 138 mmHg: Baseline systolic BP (stage 2 hypertension range)
- 3,400 mg/day: Average U.S. sodium intake (well above recommended limit)
- 2,300 mg/day: AHA daily sodium limit (upper intake target)
- 1,500 mg/day: Ideal DASH-sodium target (low-sodium trial arm)
Why baseline matters
Every response is measured against a starting point.
Measuring intake
24-hour urine sodium is the clinical gold standard.
Measuring pressure
Multiple resting readings averaged to reduce noise.
Establishing the Salt-Sensitivity Phenotype
Some people show large BP swings with sodium; others barely move.
- ~25%: Salt-sensitive share of adults (general population estimate)
- ~50%: Salt-sensitive among hypertensives (higher prevalence with hypertension)
- 5–10 mmHg: BP swing, sensitive phenotype (per gram sodium change)
- 1–3 mmHg: BP swing, resistant phenotype (per gram sodium change)
Who tends to be sensitive
Older, Black, diabetic, and CKD patients more affected.
Testing protocols
Low- and high-sodium diet phases compared directly.
Underlying mechanisms
Kidney sodium handling and vascular tone both involved.
Adopting the DASH Eating Pattern
Fruits, vegetables, low-fat dairy replace processed, high-sodium foods.
- −1,000 to −1,900 mg: DASH sodium reduction (typical dietary shift)
- 4,700 mg/day: Potassium target (from fruits and vegetables)
- 8–10/day: Fruit & vegetable servings (core DASH recommendation)
- 2–3/day: Low-fat dairy servings (calcium and protein source)
What changes on the plate
Processed snacks and cured meats are swapped out.
Potassium's role
Higher potassium helps counteract sodium's pressor effect.
Adherence support
Meal plans and counseling improve sustained adoption.
Tracking the Response Over Weeks
Blood pressure change is followed across several weeks of adherence.
- 8 weeks: Original DASH trial duration (1997 landmark trial length)
- ~2 weeks: BP response onset (early measurable change)
- 4–6 weeks: Response plateau (effect largely stabilizes)
- Weekly: Monitoring frequency (diet diary and BP logs)
Early changes
Fluid shifts produce the first measurable BP drop.
Sustained changes
Vascular adaptation continues over following weeks.
Tracking tools
Home cuffs and logs improve measurement reliability.
Systolic Reduction and Individual Variation
Effect size differs sharply between salt-sensitive and resistant individuals.
- −8 to −11 mmHg: Average drop, DASH + low-Na (combined intervention effect)
- up to −12 mmHg: Drop, salt-sensitive group (largest measured reduction)
- ~2–4 mmHg: Drop, salt-resistant group (smaller measured reduction)
- ~14%: CVD risk reduction (per 5 mmHg systolic drop)
Not a uniform effect
Same diet, very different outcomes across patients.
Clinical implication
Phenotype can help set realistic expectations upfront.
Beyond blood pressure
Cardiovascular risk falls alongside the pressure drop.