What is salt
Salt, or sodium chloride (NaCl) is ubiquitous. It has been the most commonly used seasoning in virtually all human cultures. More imporatanly, salt is essential to the life of many highly evolved organisms. In particular, our central nevrous system depends on sodium ions to transmit signals. Every muscle movement requires sodium! Salt is also constantly removed from our bodies through urine and sweat. Replenishing it is necessary, but not nearly at the rate at which most people consume salt as a part of their daily diet.
What is blood pressure
One of commonly used vital signs, blood pressure is a measurement of the force with which blood vessels are expanded by the blood that circulates through them. This pressure is primarily caused by the heart pushing blood through arteries. The pulsating nature of this process results in two separate measurements: systolic and diastolic. The first one is the maximum force applied to the blood vessels, the other represents the force during the ‘low tide’ of the cycle. High blood pressure is a significant health risk which, if left untreated, can cause a stroke. While both higher and lower than normal readings are often unacompanied by symptoms, low blood pressure is frequently not seen as an important problem (unless it is a manifestation of other conditions).
Does salt raise blood pressure?
The short answer is “yes” and the evidence for this answer is quite solid. A recent study proved that there is a direct correlation between the amount of sodium present in urine (and therefore also present in a person’s body) and higher blood pressure readings. The same study also indicated that higher levels of potassium could be associated with lower blood pressure.
The main mechanism through which sodium affects blood pressure has been long suggested. Salt causes increased water retention, a serious condition with many side effects, higher blood pressure being just one of them. However, the specifics of this link are not yet known.
What is sodium sensitivity?
What complicates the situation is the fact that the effects of sodium consumpiton are not the same in different individuals, as well as different stata of the population. So, while the fundamental link between sodium and blood pressure remains true, it is not manifested with the same force in all people. Age, genetics, race and a host of other factors play a role. The multifaceted nature of sodium sensitivity makes it difficult to screen individuals in order to find out how they may be affected by high salt consumption. And even if a person knew that eating more salt is less dangerous for them, for how long can this remain true, considering that age is a factor in salt sensitivity?
Another compication comes form the fact that even when prescribed, people rarely reduce their sodium intake to recommended levels. It is therefore difficult to determine, how much of a problem sodium is for any particular individual without a thorough study and screening.
Final word of caution
Every now and then, a new study comes out which questions the importance of controling sodium intake. Media outlets tend to cover such stories, as they represent a departure from what people are told at the doctor’s office. It is important to remember that such studies (often worthwile) are a part of the scientific process and cannot be understood without a broader context. The issue of salt sensitivity demonstrates how there are many factors affecting blood pressure, and much remains to be studied. For the time being, the link between sodium and blood pressure continues to be a plain fact of mainstream medicql science.