Sodium chloride (NaCl), or normal table salt, is an essential nutrient for normal function of the human body. But like many aspects of life, too much of a good thing can sometimes be bad for you.
Electrolytes such as sodium and chloride are used in the body in many important chemical reactions. Since the beginning of our recorded history, man has recognized the benefits of salt in the diet, as well as its use as a preservative. Salting foods such as meats can keep the meat from rotting so quickly. This happens because the salt draws fluid out of the harmful bacteria, thereby killing them and keeping the meat fresh.
The same fluid effect is seen with sodium chloride in our bodies. Eating salty foods increases the amount of salt dissolved and transported in your bloodstream. Your blood becomes “hypertonic” and you get thirsty. This is the body’s mechanism to get you to drink and dilute the blood. Barkeepers know this; that’s why they put salty foods like peanuts and pretzels out to eat – so you’ll drink more.
The more salt there is in the blood, the more fluid is drawn into your bloodstream. In many individuals, this extra volume in the bloodstream will raise the blood pressure. In “salt-sensitive” people, the elevation can be dramatic. Salt may also affect the walls of blood vessels, causing them to become stiffer and raising the blood pressure.
Salt-sensitivity is seen more in older individuals, African-Americans, and persons with a family history of high blood pressure. Overall, it is estimated that 26 percent of Americans with normal blood pressure and 58 percent of those with hypertension are salt-sensitive.
In general, we get a lot of salt in our American diet. Pre-prepared and processed foods usually have large amounts of extra salt in them, both for taste and to serve as a preservative. Many of us have become so accustomed to the taste of salt in foods that even when a small amount is removed, the food tastes too bland. Many individuals are in the habit of salting foods even before they taste it.
The amounts of sodium and chloride in our body systems are regulated primarily by the kidneys. If there is too much salt in the blood, hormones are stimulated to get rid of it through the kidneys.
Diuretics, or fluid pills, are medicines used to treat high blood pressure. They work by eliminating extra sodium and water in the urine. These drugs work in the kidneys and have remained one of the first-line treatments for high pressure for many years.
For persons who have or are at risk for developing high blood pressure, restriction of dietary salt should be a priority. Most experts recommend a salt intake of around 1,500 mg a day for these individuals. Most Americans are eating much higher amounts of salt each day, around 3,000 mg or more.
Salt substitutes can be both helpful and harmful. They usually contain other electrolytes, such as potassium salts, thus eliminating the sodium. However, extra potassium may be detrimental in some medical conditions and with certain medications.
Finally, some claim that sea salt is a “healthier” alternative to regular table salt. But while sea salt may contain additional trace minerals, it still consists of mainly sodium chloride. Therefore, it will probably have the same effect on your body and your blood pressure.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.