Researchers looked at 43 different studies involving nearly 1,800 people to understand how much salt affects blood pressure. They found that cutting back on salt—especially for people with kidney disease or high blood pressure—can meaningfully lower blood pressure numbers. The study showed that reducing salt by about 2.4 grams per day (roughly what’s in one teaspoon) dropped systolic blood pressure by 4.5 points in kidney disease patients and 2.3 points in people with high blood pressure. This research confirms that eating less salt is one of the most practical and effective ways to control blood pressure, particularly for people with kidney problems.

The Quick Take

  • What they studied: How much blood pressure drops when people eat less salt, and whether the effect is different for people with kidney disease versus high blood pressure versus people with normal blood pressure.
  • Who participated: Nearly 1,800 people across 43 different research studies. Some had kidney disease, some had high blood pressure, and some had both conditions or neither.
  • Key finding: Cutting salt by about 2.4 grams per day (roughly one teaspoon) lowered the top blood pressure number by 4.5 points in kidney disease patients and 2.3 points in high blood pressure patients. The effect was smaller but still present in people without these conditions.
  • What it means for you: If you have kidney disease or high blood pressure, reducing salt intake is one of the most effective dietary changes you can make to lower your blood pressure naturally. Even small reductions in salt can add up to meaningful improvements. However, talk to your doctor before making major dietary changes, especially if you have kidney disease, as they may have specific salt recommendations for your situation.

The Research Details

This was a meta-analysis, which means researchers searched through medical databases to find all high-quality studies published since 2000 that tested whether eating less salt lowers blood pressure. They only included studies that actually measured how much salt people ate by collecting their urine over 24 hours—this is the most accurate way to measure salt intake. The researchers then combined the results from all 43 studies using statistical methods that account for differences between studies. They tested different mathematical patterns to see which one best described the relationship between salt reduction and blood pressure change.

By combining results from many studies, researchers can see the bigger picture and get more reliable answers than any single study could provide. Using 24-hour urine collection to measure salt intake is important because it’s much more accurate than asking people to remember what they ate. This approach gives doctors and patients confidence that the findings are real and trustworthy.

This meta-analysis is strong because it included 43 randomized controlled trials—the gold standard type of research. The large sample size of 1,759 people across multiple studies makes the results more reliable. The researchers used proper statistical methods to combine the studies fairly. However, the results were published in 2026, so this is very recent research that may still be undergoing peer review in some contexts.

What the Results Show

The main finding was that reducing salt intake has a clear, dose-dependent effect on blood pressure—meaning the more salt you cut, the more your blood pressure drops, in a predictable way. For people with kidney disease, cutting 2.4 grams of salt per day lowered their top blood pressure number (systolic) by 4.5 points and their bottom number (diastolic) by 2.2 points. For people with high blood pressure but normal kidney function, the effect was smaller but still meaningful: a 2.3-point drop in systolic pressure and 1.1-point drop in diastolic pressure. Interestingly, even people without kidney disease or high blood pressure saw small blood pressure improvements from eating less salt, though the effect was much smaller. The relationship between salt reduction and blood pressure lowering was linear, meaning it follows a straight-line pattern—cut more salt, get more benefit.

The research confirmed that the effect of salt reduction is strongest in people with kidney disease, suggesting their bodies are more sensitive to salt intake. The consistency of results across 43 different studies from different countries and time periods strengthens confidence in these findings. The study also showed that the benefits apply regardless of age, gender, or other factors studied.

This research aligns with and strengthens previous findings about salt and blood pressure. It provides more precise measurements of exactly how much benefit people can expect from specific amounts of salt reduction. The focus on kidney disease patients fills an important gap, as previous research had focused more on people with high blood pressure in general.

The studies included were mostly short-term (weeks to months), so we don’t know if the benefits continue long-term or if people can stick to low-salt diets for years. Most participants were adults, so results may not apply to children. Some studies measured blood pressure in clinical settings rather than at home, which can sometimes give different readings. The research doesn’t explain why kidney disease patients see bigger benefits from salt reduction, just that they do. Individual responses to salt reduction vary, so some people may see bigger improvements than others.

The Bottom Line

If you have kidney disease or high blood pressure, reducing salt intake should be a priority dietary change (high confidence). Aim to cut salt by about 2.4 grams per day if possible, though even smaller reductions help. If you have normal blood pressure and normal kidney function, reducing salt is still beneficial but the improvements will be smaller (moderate confidence). Always discuss salt reduction with your doctor first, especially if you have kidney disease, as some kidney conditions require specific sodium management.

This research is most important for people with chronic kidney disease and people with high blood pressure. It’s also relevant for anyone wanting to prevent high blood pressure. People with certain kidney conditions that require higher sodium intake should check with their doctor before reducing salt. Pregnant women and people taking certain medications should also consult their doctor about salt intake.

Most studies showed blood pressure improvements within 4-12 weeks of reducing salt intake. However, the full benefits may take several months to appear. Consistency matters more than perfection—steady salt reduction over time produces better results than occasional efforts.

Want to Apply This Research?

  • Track daily sodium intake in milligrams and record blood pressure readings (top and bottom numbers) at the same time each day. Set a goal to reduce sodium by 500-1000mg per week until reaching your target, and monitor how your blood pressure changes weekly.
  • Use the app to log meals and identify high-salt foods in your diet (processed foods, canned goods, restaurant meals). Set reminders to choose lower-salt alternatives and track your progress toward a daily sodium target set by your doctor.
  • Establish a baseline by recording your current sodium intake and blood pressure for one week. Then gradually reduce sodium while tracking blood pressure weekly. Create a graph showing the correlation between sodium reduction and blood pressure changes over 8-12 weeks to visualize your personal results.

This research summary is for educational purposes only and should not replace professional medical advice. Before making significant changes to your salt intake, especially if you have kidney disease, high blood pressure, or take medications affecting sodium balance, consult with your doctor or registered dietitian. Individual responses to dietary changes vary, and what works for one person may not work the same way for another. If you have chronic kidney disease, your doctor may have specific sodium recommendations that differ from general guidelines. This meta-analysis combines results from multiple studies, but individual circumstances may require personalized medical guidance.