Salt (sodium chloride) is a necessary component for the functioning of all cells in the body, and the body cannot manufacture sodium. Without sodium we could not transport nutrients or oxygen, transmit nerve impulses, or move muscles, including smooth and skeletal muscle. Salt regulates the water content of the body. An adult human being contains about 250 grams of salt, which would fill three to four saltshakers, but salt is lost continually through sweat, urine, and stool, and must be replaced. Salt deficiency causes headaches, weakness, and nausea, and ultimately death. Acute salt overdose (1 gram per kg body weight) can lead to death. Chronic salt overload is thought to contribute to hypertension and congestive heart failure.
Controversy abounds regarding our optimal salt intake. The prevailing message is that we should avoid salt intake. The CDC has suggested that reducing salt consumption is as important to long-term health as quitting smoking. Yet, the reduced salt initiative is somewhat difficult to defend. Some evidence over the past few years suggests that restricting salt intake may actually increase our likelihood of dying prematurely, but this evidence is not very strong.
Most Americans consume 3400 milligrams of sodium per day, which is well above the current guidelines, which suggest that healthy people consume no more than 2300 milligrams per day. Keep in mind that sodium comprises 40% of salt itself (sodium chloride), so that 3400 milligrams of sodium equals 8.5 grams of salt. There are data to suggest high salt intake corresponds to higher blood pressure and by extension, increased cardiovascular and stroke risk, and worsening kidney function, though most of these studies have some flaws. The lower limit of sodium intake is also not well-defined, as there are data that show that those on very low sodium diets have worsened cardiovascular outcomes. Most experts agree that 2300 milligrams sodium intake per day is a reasonable target for those above age 51, those with hypertension, kidney disease, or African-Americans.
Other benefits of low salt diets
Other benefits of low salt diets include decreased risk of osteoporosis, decreased risk of kidney stones, improvement in heart muscle stiffness, and improved response to insulin.
High sodium foods
Processed foods are typically high in salt. This includes deli meat, canned soups, and condiments. Ten types of foods account for more than 40 percent of sodium consumption in the US. Breads/rolls, deli meat, pizza, soups, cheeseburgers, cheese, pasta, potato chips, pretzels and popcorn are known culprits. It has been estimated that 89% of Americans’ salt intake is salt already embedded in the food before it is prepared. The best way to lower sodium intake is to avoid foods in cans, jars, boxes and bags. Try for meals containing 600 mg sodium or less.
Low salt diets
Most experts agree that it takes only three weeks to retrain your taste buds to accept a lower salt diet. Consider flavoring foods with lemon, rosemary, garlic, and pepper. Also try to avoid salt substitutes; many contain potassium which may be harmful to those on certain medications.
FDA Food Labeling Guide
l Requires disclosure if sodium content exceeds 480 mg sodium per serving
l Light sodium = usual level reduced by 50%
l Reduced sodium = usual level reduced by 25%
l Low sodium = 140 mg or less per serving
l Very low sodium = 35 mg or less per serving
l Sodium-free = very tiny amount of sodium per serving