Scientists studied over 500 Chinese adults to understand how their genes affect salt sensitivity—the way their bodies respond to eating salty foods. They found that certain genetic variations in a gene called NR3C2 influence how much salt affects blood pressure and whether someone develops high blood pressure over time. The study followed people for 14 years, tracking their blood pressure changes when they ate low-salt and high-salt diets. These findings suggest that some people’s genes make them more sensitive to salt’s effects on blood pressure, which could help doctors better predict who is at risk for developing high blood pressure.

The Quick Take

  • What they studied: How different versions of a specific gene (NR3C2) affect how sensitive people’s blood pressure is to salt intake and whether they develop high blood pressure over time
  • Who participated: 514 adults from 124 families in northern China, ranging from people with normal blood pressure to those at risk for high blood pressure, studied over 14 years
  • Key finding: Two specific genetic variations (rs5522 and rs3910053) were linked to how much salt affects blood pressure. People with the rs3910053 variation were more likely to develop high blood pressure over the 14-year study period
  • What it means for you: Your genes may partly determine how much salt affects your blood pressure. If you have certain genetic variations, you might benefit more from reducing salt intake. However, this doesn’t mean you’re destined to have high blood pressure—lifestyle choices still matter significantly

The Research Details

Researchers recruited 514 adults and had them follow a controlled eating plan to see how their bodies responded to different amounts of salt. First, participants ate their normal diet for 3 days. Then they switched to a very low-salt diet (3 grams per day, which is about half the recommended amount) for a week, followed by a very high-salt diet (18 grams per day, which is about 3 times the recommended amount) for another week. During each phase, researchers measured their blood pressure carefully. The scientists then followed these same people for 14 years to see who developed high blood pressure and who didn’t.

The researchers used genetic testing to identify specific variations in the NR3C2 gene—think of these as different ‘versions’ of the same instruction manual in people’s DNA. They looked at two particular genetic variations (called SNPs) and analyzed whether people with different versions had different blood pressure responses to the salt changes.

This research approach is important because it combines two types of information: how people’s bodies actually respond to salt in real time (measured during the diet phases) and what happens to their health over many years (the 14-year follow-up). This combination helps scientists understand whether genetic variations that affect short-term salt sensitivity also predict long-term health problems like high blood pressure. The controlled diet phases ensure that salt intake is the main variable being tested, making the results more reliable.

This study has several strengths: it followed real people over a long period (14 years), used controlled diet conditions to test salt sensitivity, included genetic testing, and tracked actual health outcomes. However, the study was conducted only in Chinese adults, so the findings may not apply equally to other populations. The study size of 514 people is moderate—larger studies might provide more definitive answers. The researchers registered the study in advance, which is a good sign of scientific rigor.

What the Results Show

The study identified two genetic variations in the NR3C2 gene that significantly affected how salt influences blood pressure. The first variation (rs5522) showed a notable effect during the low-salt phase, where it was associated with smaller increases in pulse pressure (the difference between the top and bottom blood pressure numbers). During the high-salt phase, this same variation was linked to changes in systolic blood pressure (the top number).

The second variation (rs3910053) showed even more significant effects. During the high-salt phase, people with this variation experienced different changes in systolic blood pressure, diastolic blood pressure (the bottom number), and mean arterial pressure (average pressure throughout the heartbeat). Most importantly, over the 14-year follow-up period, people with the rs3910053 variation had a higher risk of developing high blood pressure compared to those without it.

These findings suggest that the NR3C2 gene plays an important role in determining how sensitive someone’s blood pressure is to salt intake. The gene produces a protein that helps the body regulate salt and water balance, which directly affects blood pressure.

The study found that the effects of these genetic variations were most noticeable during the high-salt phase of the diet, suggesting that people with certain genetic variations are particularly vulnerable to the blood pressure-raising effects of excess salt. The long-term follow-up data showed that genetic variations affecting short-term salt sensitivity also predicted who would develop high blood pressure years later, indicating that salt sensitivity is a meaningful indicator of future health risk.

This research builds on earlier studies showing that salt sensitivity varies between individuals and has a genetic component. Previous research suggested that the mineralocorticoid receptor (the protein produced by the NR3C2 gene) was involved in salt sensitivity, but this study provides specific genetic evidence in a Chinese population. The findings align with the understanding that salt affects blood pressure through mechanisms involving hormone regulation and fluid balance in the body.

The study was conducted only in Chinese adults, so the results may not apply equally to people of other ethnic backgrounds, as genetic variations can differ between populations. The study included 514 people, which is a reasonable size but not extremely large—larger studies might reveal additional genetic variations or confirm these findings more definitively. The study measured blood pressure during controlled diet phases, which is more controlled than real-world eating but may not perfectly reflect how people respond to salt in their everyday lives. Additionally, the study didn’t account for all possible factors that influence blood pressure, such as stress levels or physical activity patterns during the 14-year follow-up.

The Bottom Line

If you have a family history of high blood pressure, you may want to discuss genetic testing with your doctor to determine if you carry these genetic variations. Regardless of your genetics, reducing salt intake is a proven way to help manage blood pressure—aim for less than 2,300 mg of sodium per day (about 1 teaspoon of salt). If you have these genetic variations, you may benefit even more from limiting salt. These recommendations are supported by strong evidence and should be discussed with your healthcare provider, especially if you have high blood pressure or are at risk for it.

This research is most relevant for people with a family history of high blood pressure, people of Chinese descent (since the study was conducted in this population), and anyone interested in understanding their personal risk factors for high blood pressure. People who already have high blood pressure or are at risk should definitely pay attention to salt intake. However, these findings don’t mean that people without these genetic variations can ignore salt intake—salt affects everyone’s blood pressure to some degree.

If you reduce your salt intake, you may see changes in blood pressure within days to weeks. However, the long-term benefits of salt reduction for preventing high blood pressure develop over months and years. The genetic variations studied here influence risk over many years, so this is a long-term health consideration rather than something that will change overnight.

Want to Apply This Research?

  • Track daily sodium intake (in milligrams) and correlate it with blood pressure readings taken at the same time each day. Record readings after 3-5 days of low-salt eating and again after 3-5 days of higher-salt eating to see your personal salt sensitivity pattern
  • Set a daily sodium target of 1,500-2,300 mg and use the app to log meals and their sodium content. Create alerts when approaching your daily limit, and track which foods contribute most to your sodium intake so you can identify easy swaps (like choosing low-sodium bread or reducing processed foods)
  • Establish a baseline blood pressure reading, then monitor weekly while maintaining consistent salt intake. After 4-6 weeks, adjust salt intake and monitor for changes. Keep a 3-month rolling average to account for natural blood pressure fluctuations, and share trends with your healthcare provider during annual checkups

This research describes associations between genetic variations and blood pressure responses to salt, but does not establish that these genes cause high blood pressure. Genetic testing for these variations is not currently recommended as a standard clinical practice. If you have high blood pressure or are concerned about your blood pressure, consult with your healthcare provider before making dietary changes or seeking genetic testing. This information is educational and should not replace professional medical advice. Individual responses to salt intake vary, and factors beyond genetics—including overall diet, exercise, stress, and medications—significantly influence blood pressure.