Scientists warn that chloride is just as bad for those with high blood pressure as salt is.
Too much salt in the diet – and specifically sodium – is widely acknowledged as a major risk factor for high blood pressure however, scientists have found that salt’s constituent chloride might also play an important role. To-date, the role of chloride in hypertension has received little attention from scientists.
After analyzing data from almost 13,000 patients with high blood pressure followed up over 35 years, the researchers found that low levels of chloride was associated with a higher risk of death and cardiovascular disease, making it an independent indicator of mortality risk in people with hypertension. In fact, those with the lowest level of chloride in their blood had a 20 percent higher mortality rate compared to the other subjects.
According to Dr. Sandosh Padmanabhan of the Institute of Cardiovascular and Medical Sciences in Glasgow, “sodium is cast as the villain for the central role it plays in increasing the risk of high blood pressure, with chloride little more than a silent extra in the background. However, our study has put the spotlight on this under-studied chemical to reveal an association between low levels of chloride serum in the blood and a higher mortality rate, and surprisingly this is in the opposite direction to the risks associated with high sodium. It is likely that chloride plays an important part in the physiology of the body and we need to investigate this further.”
Chloride is already measured as part of routine clinical screening and so monitoring of chloride levels could easily be incorporated into clinical practice to identify individuals at high risk.
Dr. Padmanabhan and colleagues, whose study was published in the journal Hypertension, said that there seems to be a grey area since research shows us that excess slat is a bad thing, yet this study shows that higher levels of chloride in the blood seems to be an independent factor that is associated with lower mortality and cardiovascular risk. He said more investigation is warranted and it is too early to draw any conclusions about relating this finding to salt intake and diet.