Taste buds can adapt to a low salt diet, researchers discover

23 May 2022 --- Researchers have uncovered that it is possible for hypertension patients to acclimate their taste perceptions to a low sodium diet over time. 

This is according to a study presented at ACNAP-EuroHeartCare Congress 2022, a scientific congress of the European Society of Cardiology (ESC).

“One of the major barriers to sticking to a low salt diet is that people do not like the taste, but few studies have addressed this issue,” says study author Professor Misook Chung of the University of Kentucky, Lexington, US. 

“Our pilot study in patients with high blood pressure shows that it is possible to change taste perception and learn to like food with less salt.”

Hypertension affects more than one billion people worldwide and is the leading global cause of premature death. 

Recently, NutritionInsight reported that new research funded by the US National Institutes of Health found that those who develop high blood pressure-related disorders during pregnancy have a significantly higher risk of future cardiac events, such as heart attack or stroke. 

Eye on sodium intake
A healthy lifestyle, including salt restriction, is recommended to delay the need for blood pressure-lowering drugs or complement their effects. 

However, the benefits of reduced sodium intake on blood pressure tend to diminish with time, partly due to poor adherence, the scientists warn.

The researchers developed the Sodium Watchers Programme – Hypertension (SWaP-HTN) for gradual taste adaptation to low salt food.The researchers developed the Sodium Watchers Programme – Hypertension (SWaP-HTN) for gradual taste adaptation to low salt food. 

The study examined its short-term effects on sodium intake, blood pressure, preference for salty food, and enjoyment of a sodium-restricted diet. A total of 29 adults with hypertension were randomly assigned to the intervention or usual care in a 2:1 ratio. 

Participants in the usual care group received routine medical and nursing care for hypertension, including advice to follow a sodium-restricted diet and take prescribed medications.

The program was individualized to each patient’s barriers and weekly goals and included salt added at the table, salt used during cooking, grocery shopping and eating in restaurants. 

Participants received an electronic device that detects salt content to identify and avoid high salt food.

Utilizing tech
According to Chung, one of the first steps was for patients to realize how much salt they were eating. 

“Using the electronic device, they could test the salt content of restaurant meals and ask the chef to reduce or eliminate salt on their next visit. They also used it at home to lower the salt content in their cooking,” she details.

Some study participants automatically added salt to the table before tasting the food, so they were asked to count the number of ‘shakes’ and set goals for reducing it. 

“Most participants removed the salt shaker from the table within three weeks,” explains Chung.

At baseline and 16 weeks, all participants provided a 24-hour urine sample to assess sodium intake and had their blood pressure measured. In addition, their preference for salty food and enjoyment of a salt-restricted diet was evaluated on a 10-point scale.

The average age of participants was 63 years and 55% were men. Three patients withdrew from the study, and the final analysis included 17 and nine participants in the intervention and usual care groups, respectively. 

The researchers compared changes between groups, from the study’s baseline mark to its completion between. Overall, the intervention led to a significant reduction in sodium intake and increased enjoyment of a salt-restricted diet. 

There was a trend of decreasing mean systolic blood pressure in the intervention group, from 143.4 to 133.9 mmHg, but it was not statistically significant. They concluded that intervention did not change their preference for salty food.

30% reduction from baseline
Chung says the sodium intake dropped by 1,158 mg per day in the intervention group, a 30% reduction from baseline, while the control group increased its daily intake by 500 mg. 

“Enjoyment of a low salt diet increased in the intervention group, from 4.8 to 6.5 on a 10-point scale, although patients still preferred salty food. Likely, the intervention did not translate to a statistically significant fall in blood pressure because of the small sample size.”

Chung concludes that it is possible to retrain the taste buds to enjoy low sodium food and gradually reduce the amount of salt consumed. “The gradual taste adaptation program has the potential to control blood pressure but needs to be tested in a larger trial with longer follow up.”

Salt in the spotlight
A recent report by Ajinomoto flagged that the weight of salt reduction responsibility should be shouldered by industry rather than consumers. Innova Market Insights observes that low/no/reduced salt claims have increased in every major region of the globe, with Europe holding the most share of new products in this arena (Global, 2017 to 2021).

In a separate study conducted recently, researchers found that a low sodium diet boosts the quality of life for heart failure patients.

In the US, the Food and Drug Administration unveiled voluntary sodium reduction targets last October for a broad range of processed, packaged and prepared foods. 

Last month, Kirin Holdings and the Miyashita Laboratory at Meiji University developed the “world’s first” chopsticks that can make food seem 1.5 times saltier with the use of a weak electric current. 

Edited by Elizabeth Green