Sodium is a mineral that helps us balance out the amount of water in our bodies and helps our nerves and muscles function properly. Our bodies also use sodium to regulate blood pressure by controlling the amount of fluid that gets into our blood. Sodium is counterbalanced in our body by potassium. Both these minerals target the same functions in our body and we need both minerals present in order for the body to function normally. The process by which our nerves function and send signals is a great example of the relationship between sodium and potassium.
Sodium and Your Nerves
All of our nerves use a combination of minerals to create a charge that travels down the nerve cell, creating a “signal” or nerve impulse that can tell the brain, spine or other nerves to do something. Potassium and sodium help form the impulse, which is called an action potential.
The concentration of sodium outside of a nerve cell is about 10 times higher than it is inside the cell. The concentration of potassium inside the nerve cell is about 20 times higher than it is outside the cell. Therefore, potassium wants to go out of the cell to balance itself out while sodium wants to go in the cell to balance itself out. However, our nerve cells actually work to keep potassium and sodium apart like this preventing them from balancing out, creating a difference in charges. The cell has a negative charge on the inside, while the outside of the cell has a positive charge. This imbalance keeps the cell ready to fire a signal by allowing sodium to rush into the cell causing a change in the voltage inside the cell.
Channels called voltage-gated ion channels generate the action potential. These channels only allow potassium and sodium in or out of the cell. A nerve is at rest when the charge inside the nerve cell is negative (about -70mV) and the charge outside the cell is positive.
When a stimulus occurs, the channels open. If the stimulus is large enough, the flood gates open and sodium rushes into the nerve cell making the charge inside the cell more positive (depolarization). The channels open in sync down the axon of the nerve causing a wave of depolarization to travel down the nerve’s axon. Once the charge inside the cell reaches about +40 mV the channel closes. The nerve re-balances itself by pumping potassium out of the cell to bring the charge inside the cell back down to -70mV (Repolarization). The charge briefly drops below -70mV during this time (Refractory period) because potassium balance point is at a lower voltage than sodium. The nerve then begins to pump sodium out of the cell and potassium back in. This brings the cell back to its resting state.
Here is a video explaining how the action potential works
Sodium is a popular ingredient in many processed foods and can come in many forms. Some examples are:
• Sodium bicarbonate (Baking soda)
• Baking powder
• Disodium phosphate
• Sodium ascorbate
• Sodium propionate
• Sodium sulfide
• Monosodium glutamate (MSG)
• Sodium nitrate or nitrite
Some of the more familiar ones are baking soda, baking powder, MSG and sodium nitrates. You will most likely find at least one of these on the ingredients label for most packaged and processed foods. The most popular form of sodium, however, is salt (sodium chloride).
Processed foods are notoriously high in sodium. We can get as much as 75% of our sodium each day just from these foods alone. Here are some examples of processed foods that are high in salt:
◦ Cold cuts and cured meats
◦ Canned foods
◦ Fast foods
◦ Instant breakfasts, Frozen dinners
◦ Ketchup, Mustard, Steak sauces
◦ Packaged Meats and Chicken
◦ Pasta dishes
◦ Pickled foods
◦ Quick dissolving medicines like Alka-Seltzer
◦ Snacks (Crackers, Cookies, Chips…)
Salt is a compound that is absolutely essential for our bodies. Sodium chloride is known as table salt. By weight, it is 40% sodium and 60% chloride. Both sodium and chloride are involved with the functioning of our nerves. There are several kinds of salts that exist around the world. Salt is a general term for ionic compounds (generally, they all look like salt). Salt acts as a preservative because it draws water out of cells. Adding salt to foods prevents bacteria from growing because it essentially dehydrates them. Food manufacturers have taken advantage of this quality to enhance the flavor of foods and to prevent bacteria from growing in the food. This is also one of the reasons why foods can sit on shelves for weeks or months at a time without spoiling. Some other common forms of salt are
• Natural salt or Sea salt (about 85% sodium chloride, 15% trace minerals)
• Himalayan salt (95% sodium chloride, 5% other minerals)
Although these salts are mostly sodium chloride, they contain minerals in small amounts that our body needs like silicon, sulfur, and phosphorus. Table salt is usually processed with chemicals that keep it from sticking together. These chemicals are compounds that may be harmful to our health. Also table salt may be heated to very high temperatures, which changes the chemical structure of the salt. Sea salts are mined from salt mines or from evaporated seawater, which does not require high temperatures.
Sodium and Your Heart
Its been widely accepted that too much sodium can increase your blood pressure and increase your risk of getting heart disease, having a heart attack, stroke or kidney failure. However, there may be more to the story than just getting too much salt in your diet.
Reviews of several studies looking at the effects of high salt diet show that high sodium levels may not be the primary reason behind an increased risk of heart disease. Instead, a combination of high sodium levels and low potassium levels may be a much stronger risk factor. This one-two punch may significantly increase your risk for heart disease more than high sodium levels alone. It does not mean that its ok to eat as much sodium (salt) as you like but it does mean that the lack of potassium in our diets is just risky for our health as having high sodium levels. Currently, the average American get twice as much sodium daily than they do potassium. This ratio is the inverse of what we should be getting, putting many of us at risk for developing heart disease. It’s important to note that the number one cause of death in the U.S is heart disease.
There is a delicate balancing act that goes on between sodium and potassium. Too much or too little of either one will throw off your body’s pH balance and also cause your blood pressure to go up. If you like salty foods, then start adding some foods to your diet that are high in both salt and potassium.
How much Sodium?
Adequate Intakes (AI) of Sodium
|Age||Male||Female||Pregnant or Lactating||Upper Limit|
|0 – 6 Months||120 mg||120 mg||–||–|
|7 – 12 Months||370 mg||370 mg||–||–|
|1 – 3 Years||1,000 mg||1,000 mg||–||1,500 mg|
|4 – 8 Years||1,200 mg||1,200 mg||–||1,900 mg|
|9 – 13 Years||1,500 mg||1,500 mg||–||2,300 mg|
|14 – 18 Years||1,500 mg||1,500 mg||1,500 mg||2,300 mg|
|18 – 50 Years||1,500 mg||1,500 mg||1,500 mg||2,300 mg|
|50 – 70 Years||1,300 mg||1,300 mg||–||2,300 mg|
|70+ Years||1,200 mg||1,200 mg||–||2,300 mg|
2,300 mg of sodium is equivalent to 1 teaspoon of salt. Processed foods are the best sources of sodium (salt). However, it’s not wise (or healthy) to turn to processed foods to get your daily requirements of sodium. There are foods though that are naturally great sources of sodium and are healthy as well. Healthy adults should not exceed 2,300 mg of sodium. Those with kidney problems, high blood pressure or are at risk for heart disease or other cardiovascular problems, should not exceed 1,500 mg of sodium per day.
Healthy Foods High in Sodium
Most, if not all packaged and processed foods are full of salt. Even packaged meats contain a hefty dose of sodium. Food manufacturers inject the meat or chicken with plenty of salt water to help kill off harmful bacteria before it’s packaged. The downside, we get meat that’s loaded with sodium. Rinsing it will help get rid of some of the salt before you cook it. As great a source of sodium as packaged and processed foods are, they should not be your source for sodium. Here are a few healthier options for getting your daily dose of sodium.
Sea salt/Himalayan salt
2,300 mg is 1 teaspoon. If you eliminate most of the salt from other foods in your diet, you can scoop out about 2/3 of a teaspoon of salt and add it to your meals throughout the day. 2/3rds of a teaspoon is roughly 1,500 mg of salt. These salts can be white, pink and reddish depending on the trace elements that are present.
Sun dried tomatoes
These tomatoes contain about 1,130 mg of sodium per cup. What’s great is that it has more potassium than sodium so these tomatoes will help boost both your potassium and sodium levels and keep them balanced.
½ a Dill Pickle contains about 570 mg of sodium. Virtually anything that is pickled will likely contain a hefty dose of sodium. A 3-4 inch sour pickle will have about 785 mg of sodium.
Pickled olives, which is how they’re usually prepared and sold, contain around 430 mg of sodium in about 14 olives. Unfortunately, when olives are pickled they lose many of their healthy compounds. Nevertheless, they are still healthy as long as you limit how many olives you eat per day.
- The Long Term Effects of Advice to Cut Down on Salt in Food on Deaths, Cardiovascular Disease, and Blood Pressure in Adults, http://summaries.cochrane.org/CD003656/the-long-term-effects-of-advice-to-cut-down-on-salt-in-food-on-deaths-cardiovascular-disease-and-blood-pressure-in-adults”>Cochrane Summaries, January 21, 2009: L. Hooper, et al.
- Sodium Intake and Mortality in the NHANES II Follow-Up Study, http://www.ncbi.nlm.nih.gov/pubmed/16490476″>American Journal of Medicine, March 2006: 119(3); 275.e7-14, H. W. Cohen, et al.
- Sodium and Potassium Intake and Mortality Among US Adults, http://archinte.ama-assn.org/cgi/content/short/171/13/1183″>Archives of Internal Medicine, July 2011: 171(13); 1183-1191, Quanhe Yang, PhD, et al.
- Why Your Sodium-Potassium Ratio Is So Important, http://www.huffingtonpost.com/2011/07/11/potassium-salt-diet-dangers_n_895124.html”>Huffpost Healthy Living, July 11, 2011: Mike Stobbe.
- Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate.