Sodium Restriction: The Devil Is in the Details

Some say that sodium is the new sugar—that salt seems to be replacing sugar as the dietary bad boy. Public health authorities have mounted campaigns to educate Americans about salt and its association with increased rates of cardiovascular disease.

Most Americans consume approximately 3300 mg per day of salt from foods, if we don’t count added table salt. This is far in excess of what they need.

Why Limit Salt Intake?

Current dietary guidelines recommend maximum daily a salt consumption lower than 2300 mg per day. For 3 populations—African-Americans, individuals older than 50 years of age, and any person who has hypertension diabetes or chronic kidney disease—a limit of 1500 mg per day is recommended.

Most health care providers are well aware of salt’s association with hypertension, heart failure, and cardiovascular disease. High salt intake has been identified as a probable cause of gastric cancer. Investigators believe that elevated salt intake damages the gastrointestinal mucosa, increasing susceptibility to cancer.

High salt diets tend to change calcium metabolism, increasing risk for osteoporosis. Researchers have been able to quantify the magnitude of bone loss in this way: each 2290 mg of sodium saps 40 mg of calcium. In the span of a decade, high calcium intake could deplete 10% of skeletal bone.

Health care providers also need to be aware of research that suggests that increasing salt in our diet may contribute to asthma’s increasing prevalence. Although the research has produced mixed results, some adult asthmatics are sodium-sensitive. When these individuals switch to a low sodium diet for 2 to 5 weeks, they often report improved lung function, decreased bronchial reactivity, and less exercise-induced bronchoconstriction. Salt reduction, of course, must be used cautiously and in conjunction with appropriate medication in patients with asthma.

Why Add Salt to Foods?

Knowing why manufacturers use salt can help retail health care providers understand why they should be recommending salt restriction for almost all Americans. Traditionally, humans have used salt to inhibit microbial growth and extend shelf life. Although that’s still a reason to add salt to processed foods, its other roles are now more important to consider. Salt is a flavor enhancer and an appetite and thirst stimulant. Manufacturers use salt in processed foods because it makes them taste good and it also increases desire for the food. Most individuals who have high salt diets are thirsty, and many satisfy that thirst with high-sugar beverages, which contribute to obesity. Salt also increases the weight of many products, and increasing the sodium content of a meal by 0.5% to 2.5% can increase its weight up to 20%. Therefore, recalling that the average American eats 3300 mg of salt every day, recommending salt restriction for almost all Americans is prudent.

Pass the Salt or Pass on the Salt

Since 1980, the American food system has delivered an amazing assortment of foods to American tables. Grocery stores offer a large number of cereals, a dairy section that is increasingly filled with nondairy soy- and almond-based milks, and canned good aisles that are resplendent with old favorites and variations on a theme. Many older individuals report opening cans of what they assumed were plain tomatoes only to find that they didn’t read the small print. Their purchases are tomatoes seasoned with Italian seasonings, jalapeno peppers, or other flavors. Few individuals actually read nutritional labels.

Reading the small print is especially important for patients who need to restrict salt intake. For retail health care providers, patient counseling needs to emphasize that avoiding the salt shaker is only one way—and a small way—to reduce sodium intake. About three-quarters of Americans’ dietary sodium comes from prepared foods. Leading sources of sodium include breads and rolls, cold cuts and cured meats, pizza, poultry, soups, fast food sandwiches, cheeses, prepared dishes from the freezer aisle, and savory snacks.

Counseling patients about sodium intake takes a few minutes, and it can reap rewards by helping patients improve several conditions. The following are some ways to focus patients’ attention on reducing dietary sodium.

Tips for Reducing Sodium Intake

• Emphasize the patient’s specific dietary salt target, and educate them that sodium, sodium chloride, and NaCl all mean “salt.” Salt also hides in monosodium glutamate (MSG), baking soda and baking powder, and the additive disodium phosphate.
• Show patients how to read nutritional labels and identify the amount of salt in products they purchaseThe Daily Value is the amount of salt recommended per day for Americans older than four years of age; for sodium, the nutritional label uses a value of 2400 mg, which is slightly more than 1 teaspoon of salt.The Percent Dealing Value (% DV) tells patients how much sodium is contained in one serving; educate patients that 5% DV or less is considered low sodium and 20% DV or more is considered high sodium.Emphasize servings sizes and show patients that a package usually contains more than one serving.
• Remind patients that if they purchase the bulk of their food from the perimeter of the grocery store, not the inner aisles, they are likely to find healthier foods that have less salt.Suggest that patients who rely on packaged, prepared, and canned foods look for “Low Sodium” labels
• Suggest that patients log their intake for 1 or 2 weeks so they can identify the source of most of their sodium.Direct patients to my-calorie-counter.com/ (which is free) or myfooddiary.com/features/food (which requires a small monthly enrollment fee) to track their sodium intakeThe American heart Association encourages patients to be “sodium sleuths” by using their free tool available here:heart.org/idc/groups/heart-public/@wcm/@fc/documents/downloadable/ucm_448279.pdf.
• Introduce patients to the DASH Eating Plan, described at dashdiet.org/default.asp. DASH was originally developed as an eating pattern to help lower blood pressure, but subsequent studies have shown that it has benefit for patients who are obese, or who have metabolic syndrome, type 2 diabetes, or post-menopausal weight gain. It effectively lowers blood pressure and cholesterol. Recent study results also show that it may improve asthma control.
• Help patients find sites that offer low sodium recipes; the American Heart Association offers a large number of innovative recipes that are low in salt.

Conclusion

Many patients associate salt restriction with a bland, unpalatable diet. With practice, patients will find that adding spices to foods is a good alternative to adding salt, and they may find home-cooked meals tastier than prepared foods. Today’s low-sodium bouillons and soups are just as delicious as the high-salt versions. Advise patients to rinse canned vegetables and beans to remove some salt, and to try using lemon juice or vinegar on vegetables as an alternative to salt. If patients can’t break the salt shaker habit, suggest they try sea salt, which has lower sodium content (approximately 1700 mg per teaspoonful).

What patients really need to know is this: salt is not an essential nutrient, it’s a flavor enhancer.

Recommended Reading

Cohen LP, Hummel SL, Maurer MS, López-Pintado S, Wessler JD. Salt taste recognition in a heart failure cohort.J Card Fail.2017 May 9. pii: S1071-9164(17)30112-4. doi: 10.1016/j.cardfail.2017.05.001. [Epub ahead of print].

Forte GC, da Silva DR, Hennemann ML, Sarmento R, Almeida JC, de Tarso Roth Dalcin P. Diet effects in the asthma treatment: A systematic review.Crit Rev Food Sci Nutr.2017 Mar 31:0. doi: 10.1080/10408398.2017.1289893. [Epub ahead of print].

Ma J, Strub P, Lv N, et al. Pilot randomised trial of a healthy eating behavioural intervention in uncontrolled asthma.Eur Respir J.2016;47(1):122-132.

Wick JY. Salt: important element, invisible menace.Consult Pharm.2012;27(11):756-762.