Salt is one of the most essential elements in the human body, involved in transmitting electrical impulses as well as maintaining fluid balances within the body. Most of the body's sodium is found inside cells; the amount of sodium in the blood is tightly regulated by the body. Because sodium attracts and holds water, excess sodium intake can cause fluid retention, particularly in individuals who are sensitive to salt.
Mechanism
Around 30 percent of Americans are sensitive to sodium, one of the two ingredients in table salt, Clemson University Extension reports. When most people eat more salt than usual, their body excretes it in urine. Sodium sensitive individuals retain the sodium. Sodium pulls fluid into cells, which results in increased fluid retention in the tissues. Since fluid, like other substances, moves downhill, fluid retention most often results in swollen feet and hands, the most dependent parts of the body. If you're sodium sensitive, watching your sodium intake helps prevent edema, or swelling in your feet.
Intake
Sodium sensitivity is most likely genetic, but can also be affected by environmental factors such as dietary intake. Americans take in far more sodium than they need. Adults ages 19 to 50 require 1,500 mg of sodium per day; people age 51 to 70 need 1,300 mg per day and those over 71 only 1,200 mg per day. Yet the average daily sodium intake for Americans is around 3,600 mg per day. Reducing your sodium intake can help prevent fluid retention, particularly if you're sodium sensitive.
High-Sodium Foods
While not adding salt at the table helps reduce your sodium intake, the largest amount of sodium in the diet by far comes from processed foods, which supply 77 percent of the daily American sodium intake, according to the Mayo Clinic. Of the rest, 12 percent comes from natural food sources and 11 percent from salt added during cooking or while eating. Frozen foods, processed or cured meats, condiments and canned foods such as soups all contain large amounts of sodium. Read labels carefully and avoid high-sodium foods; choose foods labeled low sodium instead, which have less than 140 mg of sodium per serving.
Complications
Fluid retention can cause blood pressure to rise in sodium sensitive individuals. Additional fluid in the feet and legs can also reduce blood flow to the areas and lead to skin breakdown and an increased possibility of infection, especially in diabetics who normally have poor circulation to the extremities. Edema in the feet can also cause pain and difficulty walking.
