First and foremost, sodium is not a dirty word. When determining how much sodium per day you should consume there are many variables you need to consider and even more opinions on the matter.
Sodium is one of the essential nutrients and it contributes to good health and longevity. Sodium is an electrolyte (2). Electrolytes are small chemicals that are critical to our body’s cell functioning. In addition to sodium, the other electrolytes – including potassium, calcium and magnesium – work together to help our cells create energy and maintain their physical integrity. Hormones, such as renin and aldosterone, are controlled by the kidney and adrenal glands and they help to maintain our bodies’ electrolyte balance. However, it is not enough to depend on these hormones to regulate our electrolytes. We need to monitor our electrolyte intake in order to ensure that we do not consume either too much or too little of any particular nutrient.
The current 2010 Dietary Guidelines for Americans recommend limiting sodium to less than 2,300 mg a day or 1,500 mg if you're age 51 or older or have salt sensitive health issues. Many health agencies believe this is too high. The American Heart Association (1) has recently recommended that the daily value for sodium be lowered to 1,500mg by 2020 with an intermediate goal of 2,000mg by 2013. Our basic sodium requirement is a minimum of 500 mg per day according to the National Academy of Sciences.
While studies have shown that in extreme cases, the body can survive on as little as .2 mg of sodium per day, diets that low in sodium are unlikely to contain a high enough caloric intake to ensure that the proper balance of all the essential nutrients is met. Most of us have little trouble consuming our minimum sodium requirements and the human body is adept at flushing out any sodium that is in excess of our dietary needs. In fact, the body has been shown to be able to handle diets with sodium levels as high as 30,000 mg per day. This does not, however, mean that we should not watch our daily sodium intake (3).
Hypertension and Sodium
While the average healthy adult’s body can handle a high sodium intake, as we age, the risk from consuming too much sodium begins to increase. The elderly are at particular risk for hypertension from over-consuming sodium as their bodies do not balance electrolytes as well as younger bodies do. Swedish hypertension expert Dr. Björn Folkow recommends a sodium intake in the range of 1150 mg to 5750 mg per day in order to prevent and control hypertension.
Pregnancy and Sodium Intake
It was once believed that too much sodium caused pregnant women to gain weight during their pregnancies. It is now known that eliminating too much sodium contributes to stillbirths and low birth weight. The American College of Obstetrics and Gynecology now advises pregnant women to avoid severely restricting their daily sodium intake.
A very important concept when considering how much sodium per day is healthy is the ratio of sodium to potassium in our diets (4). Most people do not consume enough potassium as a part of their daily diet. We should be eating 4.7 grams (that’s grams, not milligrams) of potassium every day. Potassium works with sodium to regulate the water in our bodies. It is believed that in addition to controlling our sodium intake, increasing our potassium intake helps to curb hypertension. It is currently theorized that potassium helps the body to flush out excess sodium. Additionally, a high sodium-potassium ratio has been linked to cardiovascular disease and mortality (5). That is, diets high in sodium and low in potassium are disease-causing. By ensuring that we maintain a high potassium and low sodium diet, we increase our overall health and our body’s ability to ward off disease. The bottom line in determining how much sodium per day to consume is that we need to avoid excess salt and add potassium-rich foods – bananas, potatoes, spinach, prunes, cantaloupe – to our regular diets.