Quiz: Test Your Salt Smarts

Salt is made up of sodium and chlorine (chemical name: "sodium chloride"). But there are other forms of sodium in food, including baking soda (sodium bicarbonate) and food additives, such as monosodium glutamate (MSG), sodium nitrite, and sodium benzoate. Any form of sodium adds to your intake, but salt makes up about 90% of the sodium you get.

The human body needs some sodium to work right. Sodium helps control your blood pressure, blood volume, and the balance of other fluids in your body. It also helps with your nerves and muscles.

But your body needs only 180 mg to 500 mg a day. That's less than the amount in 1/4 teaspoon of salt.

Only about 6% of our daily sodium comes from salt added at the table. About 5% comes from salt added during cooking. Only 12% is from foods with natural sources of sodium while up to an estimated 75% comes from processed or restaurant foods. The easiest way to cut down on sodium is to eat more home-cooked meals made from fresh ingredients.

By far, the biggest health problem caused by a high-salt diet is high blood pressure. On average, the more salt you get, the more likely you are to have high blood pressure. High blood pressure raises your risk for stroke, kidney problems, heart failure, blindness, and heart attacks.

You can help counter the bad effects of a high-salt diet with physical activity. Studies show that the more active you are, the less your blood pressure rises from a high-salt diet. So if you are not active, you need to be even more careful about eating less salt.

Too much salt can have bad effects on the heart, kidneys, and blood vessels. According to the CDC, too much sodium can raise your risk of having heart attack or a stroke.

The American Heart Association recommends an ideal limit of 1,500 mgs of sodium per day and no more than 2,300 mgs for adults. On average, Americans get more than 3,400 mg of sodium per day, or the amount in about 1 1/2 teaspoons of salt. 

Certain people are more prone to high blood pressure or at risk from its effects. For these groups -- including people 51 or older, African-Americans, and people who have high blood pressure, diabetes, or chronic kidney disease --1,500 mg per day is the recommended maximum amount of sodium. Some people may need to get even less.

Men eat more sodium than women, mainly because they eat more food. On average, American men eat between 3,100 mg and 4,700 mg of sodium per day; women eat between 2,300 mg and 3,100 mg. Dietary guidelines also recommend 2,300 mg for healthy people age 2 to 50.

Sodium isn't all bad. It is used to bind and stabilize ingredients and as a preservative, flavor enhancer, and color enhancer.

While ordinary flour may have no sodium at all, self-rising flour includes leavening, which has a lot of sodium in the form of baking soda and salt. Because of that, flour contributes to the surprising amounts of sodium in baked goods. Self rising flour contains 350 mg for just 1/4 cup.

According to the CDC, bread products contribute 354 mg of sodium per day to the average American diet. Other surprising sources of salt include dairy products (one cup of low-fat cottage cheese contains 918 mg); canned soups, sauces, and vegetables (one cup of canned tomato sauce has 1,284 mg); and deli meats (two slices of salami have 822 mg).

It can take a while to adjust to a low-salt diet. Salt is an acquired taste, but most of us acquired it as children. As adults, after years of eating overly salted foods, we have to make a big effort to changing our tastes. Experts say it takes about 8 to 12 weeks.

Table salt, sea salt, and kosher salt are all the same thing: sodium chloride. And they all have the same sodium content (40%). The differences are primarily in texture and taste.

Table salt is made from rock salt harvested from inland deposits (with iodine sometimes added as an extra nutrient). Kosher salt is made from similar sources, but it's usually additive-free and has a coarser texture. Sea salt, as its name suggests, is harvested from evaporated seawater. Consequently, it has a slightly different flavor. In the end, though, they all contribute equally to your total sodium consumption. 

Most sports drinks contain electrolytes, which are minerals found in your bloodstream. They include sodium, potassium, and calcium. Electrolytes in sports drinks are meant to put back what you lose through sweat during exercise. If you drink them without sweating enough to lose these minerals, you could be increasing your sodium intake.

Food labeling rules allow up to 5 mg per serving in a product labeled "sodium-free." Products labeled "very low-sodium” are allowed to have up to 35 mg per serving. "Low-sodium" means 140 mg or less. "Reduced sodium" means the usual sodium level has been cut by at least 25%. "Unsalted," "without added salt," and “no salt added” mean that it contains no extra salt beyond the amount that occurs naturally in the food.