An Indian-origin doctor, along with other researchers from Birmingham, in an interesting study, have found that reducing salt intake by just one spoon a day for one week can result in lowering blood pressure, even among individuals already on antihypertensive drugs.
Dr Deepak Gupta, Associate Professor of Medicine at Vanderbilt University Medical Centre and co-principal investigator of the study, said, “We previously didn’t know if people already on blood pressure medication could actually lower their blood pressure more by reducing their sodium intake.”
However, the results of the study, published in JAMA Network, showed that 70-75 percent of all individuals, regardless of their medication use, experienced a reduction in blood pressure by lowering sodium intake for just one week.
Short span yet quick effect
Researchers from Northwestern Medicine, Vanderbilt University Medical Centre, and the University of Alabama have jointly conducted this pivotal research. An intriguing aspect of this study is its approach to dietary sodium intake.
The study spanned just one week and involved 213 middle-aged to elderly participants. It employed a prospectively allocated diet order crossover method to compare the effects of a low-sodium diet against a high-sodium diet.
During this one-week low-sodium intervention, the median sodium intake was approximately 1.3 g/day, equating to a reduction of about 1 teaspoon of table salt (2.3 g of sodium) daily. The findings were striking.
“1 week of a low-sodium diet resulted in an average 8 mmHg reduction in systolic blood pressure versus a high-sodium diet,” the study reported.
This change was associated with a median 6 mmHg reduction in systolic blood pressure, a result comparable to what is typically achieved through medication.
Why the findings are important
This short-term study’s findings are important for healthcare providers and patients alike, highlighting the significant and rapid benefits of reducing sodium intake. The results suggest that even small, manageable changes in diet can yield substantial health benefits in a relatively short period.
The finding is especially relevant for individuals on blood pressure medication, as it suggests that dietary changes can enhance the effectiveness of these drugs.
Speaking to South First, Dr Abhay G, an endocrinologist at Sagar Hospitals, says, “The study’s quick timeframe is significant for a couple of reasons. First, it shows that dietary interventions can have rapid effects on health — a crucial aspect for patients seeking immediate improvements in their blood pressure management. Secondly, it emphasises the potential of non-pharmacological approaches, like diet modification, to complement traditional medication in managing blood pressure effectively and swiftly.”
The positives and negatives
This study stands out for including individuals with varying blood pressure statuses, from normotensive to hypertensive, and those undergoing different treatments. This comprehensive approach highlights that dietary sodium reduction is beneficial across a wide spectrum of the population.
Concerning the safety of such dietary changes, the study noted, “The low-sodium diet was well tolerated, with 8 percent of individuals reporting any adverse event versus 9.9 percent consuming the high-sodium diet.” This indicates that a low-sodium diet is not only effective, but also safe for most individuals.
Despite its positive findings, the study acknowledged certain limitations.
The higher than expected 24-hour urine sodium levels on the low-sodium diet suggest potential dietary nonadherence or equilibrium not being attained. Nonetheless, the results are still robust and indicative of the positive effects of sodium reduction.
What Indian doctors are saying
Dr Manohar KN, an endocrinologist at Manipal Hospital, tells South First that lifestyle measures are often advocated for in the treatment of chronic diseases. Most lifestyle measures are very effective, like salt and sugar restriction and weigh reduction.
The classical diet that doctors in India advise for hypertension is called the DASH diet — Dietary Approaches to Stop Hypertension. This involves high fibre and low salt intake. This is well known for reducing blood pressure and is as effective as a tablet.
Dr Manohar highlights the issue of sodium in our diet, “Sodium chloride, commonly known as salt, is consumed in large amounts in processed foods like canned soups, frozen dinners, sauces, and chips. While the average adult consumes about 3,500 mg of sodium daily, we actually need less than 1,000 mg for survival. This brings us to the concept of sodium sensitivity, a condition where high salt intake leads to an increase in resting blood pressure.”
He explains that there is a relationship between salt sensitivity and high blood pressure. People’s responses to salt vary significantly. Some may consume sodium without impacting their blood pressure, but those with salt sensitivity experience a different outcome.
“Even a slight increase in salt intake can disrupt their kidneys’ fluid management, leading to increased blood pressure. Salt sensitivity is more common in middle-aged, older, and overweight or obese individuals, and it tends to become more prevalent with age. For those who are salt sensitive, monitoring and reducing sodium intake is crucial for preventing or managing high blood pressure,” he adds.
To help with this, Dr Manohar recommends eating more fruits, vegetables, raw nuts, and unprocessed beans. These foods are typically low in sodium and high in potassium, making them ideal for managing sodium intake.