A new study found that an unexpected source of salt may raise blood pressure. Tap water may be the problem.
The salt in tap water may be undetectable flavor-wise. Similarly, high blood pressure is referred to as a “silent killer” as it can have no symptoms yet be deadly. It contributes to the risk of heart conditions, stroke and cardiac arrest.
Around coastal areas, saltwater can intrude into freshwater sources, making tap water saltier. Research has found that people with saltier drinking water have significantly higher blood pressure. The risk is the highest in coastal areas where seawater often contaminates the drinking supply.
More than three billion people live in coastal or near-coastal areas globally. They can ingest large amounts of salt from water that doesn’t taste salty.
The study used more than 74,000 people from the U.S., Australia, Israel, Bangladesh, Vietnam, Kenya and a few European countries. Repeatedly, the researchers found that people drinking saltier tap water had around 3.22 mmHg higher systolic blood pressure, and about 2.82 mmHg higher diastolic blood pressure. Saltier water was linked to a 26 percent higher risk of developing hypertension. The link was the strongest in people living near the coast.
The World Health Organization (WHO) does not have any guidelines for sodium levels in water. While food is most people’s main source of salt, for some people, water is a significant contributor. Digital salinity meters can be bought online. But the problem is, we don’t know what the safe range is. Brita filters and other water filters can make water taste better, but they won’t remove salt. Reverse osmosis filtration systems do remove salt from water.
While it might seem like salt you can’t taste isn’t a big deal, when you think about how much water you use in your life, you understand that it can become a large contributing factor. If you drink water, cook with it and bathe in it, you are continually coating yourself in salt. Taste amounts add up. And for people living near the coast, it’s more than a trace amount.
Dr. Rajiv Chowdhury, who led the research, didn’t hazard a guess as to how much salt in water would be a “safe” amount. He said the WHO needs stronger scientific insight, so that it can set guidelines and help keep drinking water safe.
