Excessive intake of salt has always been blamed for causing hypertension (high blood pressure). For years, health experts have thought that high consumption of salt can cause fluid retention in the arterial circulatory system, thus raising pressure on the arterial walls and causing hypertension.
The medical term used by the experts is "volume-expanded hypertension". It implies that excess salt leads to retention of extra fluid within the arterial circulatory system, causing an increase in blood volume and added pressure on the arterial walls.
However, researchers from Boston University School of Medicine (BUSM) had found otherwise in their study that was published in April 12’s issue of ‘Journal of Hypertension’. They claimed that their findings simply corrected an erroneous concept that has prevailed for many years.
They showed that conditions characterized by the expansion of blood volume from other causes, like the secretion of antidiuretic hormone or the excessive elevation of blood sugar, do not raise blood pressure because the extra fluid is accommodated by the distention of capillaries and veins. The body's circulatory system is a highly flexible vascular system with the capacity to open up new capillaries and distend veins so as to accommodate the hike in fluid volume.
Through a review of numerous studies, the researchers demonstrated that the mechanism of hypertension resulting from the excessive intake and retention of salt stimulates the sympathetic nervous system in the brain to raise adrenaline production. The increased adrenaline being circulated throughout the body can cause the arteries to constrict, resulting in resistance to blood flow and a decrease in circulatory volume.
The over-activation of the sympathetic nervous system has been recognized clinically as a characteristic of hypertension that is associated with renal failure. The latter is a typical example of elevated blood pressure from excessive salt retention.
Based on the new findings, physicians are advised to use drugs that will block the central sympathetic nervous system, in addition to diuretics that are widely utilized to treat this type of hypertension by removing excess salt.
Being a silent killer, hypertension can lead to many medical conditions including heart disease, stroke and kidney failure. People with elevated blood pressure consistently should not take it lightly and should seek help from their doctors immediately.