Khaberni - Experts warn of a hidden factor that may stand behind the rise in blood pressure for millions of people around the world, apart from the traditional reasons associated with lifestyle.
People usually link high blood pressure to factors such as excessive salt intake, lack of physical activity, and smoking. However, public health researchers point to a less obvious source of sodium, represented by the salinity of drinking water, especially in coastal areas.
With the rise in sea levels due to climate change, salty water gradually seeps into fresh water sources, leading to an increase in salt concentrations — especially sodium — in the water that people rely on for drinking and cooking.
In a scientific review and meta-analysis that included 27 studies and more than 74,000 participants from multiple countries, it was found that individuals consuming more saline water recorded higher levels of blood pressure compared to others. Their risk of developing high blood pressure also increases by up to 26%.
The results also showed a moderate increase in systolic blood pressure by about 3.22 mm Hg, and in diastolic pressure by about 2.82 mm Hg among the groups more exposed to water salinity. Although these differences seem limited at the individual level, their impact multiplies when looking at large population groups.
This problem is more evident in coastal areas, where the intrusion of seawater with groundwater raises its salinity, amid millions of residents — especially in low and middle-income countries — relying on these sources as a main source of drinking water.
Researchers warn that sodium intake is not limited to food only, as individuals may consume additional amounts without realizing it through water, even if they do not notice the salty taste.
While global efforts to prevent high blood pressure primarily focus on lifestyle modification, these findings highlight the importance of environmental factors, which still receive less attention.
Researchers indicate that the impact of water salinity could be similar to other known risk factors, such as lack of physical activity, which increase the likelihood of developing high blood pressure by percentages ranging between 15% and 25%.
Conversely, research is still limited regarding the relationship between drinking water salinity and serious heart diseases, such as heart attacks and strokes, which necessitates further studies to determine safe salinity levels and their long-term effects.
It is notable that the World Health Organization has not yet set a specific standard for sodium levels in drinking water, reflecting the need to enhance scientific evidence in this area.
While food remains the main source of sodium, experts advise monitoring the quality of drinking water — when data is available — and paying attention to the total sodium intake, especially in areas prone to high water salinity.
The report was prepared by Rajeev Choudhry, Professor of Global Health at Florida International University.
