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Nutrition Note: The Salt Story
Nowadays over consumption of salt is the issue. But our bodies need salt. More correctly, our bodies need what salt is made of. Salt is approximately 40% sodium and 60% chloride. Both sodium and chloride are required by the body. The safe minimum intake of sodium is 500 mg/day; however normal diets usually have approximately 800% of this amount5. Most people can handle higher levels of sodium when adequate intake of water is available. However, some people are genetically more susceptible to sodium than others. These people are known as "salt sensitive"3 6. In these people, as the level of sodium increases so does hypertension (see box insert on Hypertension).
Sodium is a mineral with a positive ionic charge. This positive charge is important because the charge of the sodium acts to help maintain our body’s water balance, acid – base balance, and function of muscles and nerves3 5 6. Since our body is 60% water, the role of sodium to maintain the water level correctly is vital to our survival2. Our kidney’s job is to regulate how much sodium is in our bodies. When sodium intake increases, the hormone aldosterone decreases, which is a signal to the kidney to excrete more sodium in the urine. Conversely, when sodium consumption is low, the level of the hormone aldosterone increases, which tells the kidney to conserve the sodium5. Rarely does a deficiency in sodium occur. Athletes who sweat profusively, like marathon runners and bicyclists, may need to be careful of excessive sodium loss. People with persistent diarrhea, renal disease, or trauma may also be at risk of sodium deficiency5. The source of sodium is predominantly salt, which can be found in processed food, cured meats, milk and cheese, salad dressing, and sauces. In a typical diet, 77% of the sodium comes from processed food, 12% from fresh foods, 6% added at the table, and 5% added while cooking3. Not all food has to taste salty to contain high levels of salt. Take for example corn flakes, they do not taste salty but 1 cup contains approximately 245 mg of salt4. This indicates the importance of reading labels. Low sodium foods have 140 mg or less of sodium in a serving. Eating plenty of fresh fruit and vegetables will help keep sodium levels at a minimum3.
Science indicates there is no benefit to excessive levels of sodium intake. Overindulgence in sodium can lead to hypertension in those people that are susceptible, kidney disease, and heart problems3. The general population needs to limit sodium intake. Yet, salt tastes good! Research has indicated that by lowering salt intake, over time a person’s taste adapts to and prefers the lower level of salt. On a lower salt diet, initially the person may crave salt, but with persistence over several months the desire for salt diminishes1.
The other component of salt, which is chloride, is also required by the body. The estimated level required is 750 mg/day5. Chloride has a negative ionic charge, therefore it has a role in fluid balance, acid – base balance like sodium3 5. Chloride is also found in the stomach as a part of the gastric juice hydrochloric acid, which helps to breakdown our food for absorption by the body5. With normal lifestyle, chloride deficiency does not occur. However, chloride deficiency may occur with excessive sweating, trauma, diarrhea, and renal disease.
Salt, a valuable commodity in ancient times is still required for its sodium and chloride content. However, remember more is not better. Reference for Nutrition Note: The Salt Story
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Throughout
history, salt was a precious commodity not easily obtained. In fact,
it was so precious that wars were fought over it. Salt was so valuable
that the word "salary" comes from the Latin word salarium
meaning "salt money"3. | About TARA | Who is Dr Theresa M Craig (PhD)? | Who is Clifton C Hefner? | Newsletter Archives | Appendix | Glossary | Sponsors | Contact Us | Disclaimer | Home |