Too much salt in the diet and specifically sodium is considered as a major risk factor for high blood pressure however, a new study by Indian origin scientist has found that salt's other oft-overlooked constituent chloride might also play an important role.

Researchers at the University of Glasgow have revealed that low chloride levels in the blood is an independent indicator of mortality risk in people with hypertension.

After analysing data from almost 13,000 patients with high blood pressure, followed up over 35 years, the researchers found that people with the lowest level of chloride in their blood had a 20 percent higher mortality rate compared to the other subjects.

Dr Sandosh Padmanabhan of the Institute of Cardiovascular and Medical Sciences, said that 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.

Padmanabhan said that the results from this study are confounding against the knowledge that excess salt is a bad thing, yet higher levels of chloride in the blood seems to be an independent factor that is associated with lower mortality and cardiovascular risk.

The study is published in the journal Hypertension.