Low-Salt Diet

Salt (sodium chloride) is omnipresent in the modern American diet because many packaged and prepared foods contain high levels of salt. Moreover, salting food at the table has become second nature to many people. Dietary intake of high levels of salt is thought to contribute to the progression of a number of chronic diseases. Strange as it seems to scientists, however, non-chloride sources of sodium (e.g., monosodium glutamate [MSG], sodium bicarbonate [baking soda], sodium ascorbate [a form of vitamin C]) do not increase blood pressure. Studies that have looked sodium consumption and other diseases have only looked at salt. Therefore, the problem of high sodium intake as it relates to disease may really be a problem of high salt intake.

The American Heart Association and other organizations advise people to limit their salt intake to the equivalent of no more than 3 teaspoons [6 grams] each day. Additionally, health experts advise people with certain health conditions, such as Ménière’s disease, to further limit their salt intake to levels even lower, sometimes as low as 1 teaspoon [2 grams] per day.

Why do people follow this diet?

A low-salt diet is beneficial for certain people with cardiovascular disease. Preliminary evidence has linked salt consumption with increased cardiovascular disease incidence and death among overweight people. Low-salt diets seem to be especially important for people with hypertension (high blood pressure). Salt intake has been definitively linked to hypertension in Western societies, and eliminating salt from the diet lowers blood pressure in most people.

Research studies consistently find that increased dietary salt aggravates asthma symptoms, especially in men. In a small, preliminary trial, men with asthma who doubled their salt intake for one month experienced a worsening of their lung function. Although not all of the observed effects were conclusive, several double-blind trials have provided evidence of clinical improvement following a period of salt restriction.

Other conditions that may benefit from a low-salt diet include Ménière’s disease, migraine headaches, kidney stones, gastritis, and ulcers caused by H. pylori infection. Preliminary evidence also suggests that restricting dietary salt may play a role in the prevention of certain types of cancer, including stomach, colorectal, and head and neck cancers.

Restricted levels of salt may help to preserve bone density. Short-term increases in dietary salt result in increased urinary calcium loss, which suggests that over time, salt intake may cause bone loss. Increasing dietary salt has increased markers of bone loss in post- (though not pre-) menopausal women.

Lower salt intake may also help to protect against the development of reduced insulin sensitivity, a physiological process that can lead to blood sugar regulation problems in certain people. Preliminary studies suggest that high salt intake decreases insulin sensitivity in young, healthy people, but not in older people with hypertension. Moderate restriction of salt, however, also decreased insulin sensitivity in one preliminary study of healthy people, but had no effect in other studies of people either with or without hypertension.

Salt restriction also may be helpful in reducing oedema in some people. High salt intake tends to lead to water retention that may promote the further accumulation of fluid beneath the skin.

Pregnant women who are experiencing hypertension of pregnancy should not follow a low-salt diet. As a low salt diet has not been shown to have a significant effect in reducing blood pressure during pregnancy, salt restriction is not recommended to women with gestational hypertension and preeclampsia. Additionally, unlike other conditions that cause high blood pressure, salt restriction (and use of diuretics) can worsen preeclampsia by reducing blood flow to the kidneys and placenta. In preeclampsia, unrestricted use of salt and an increased consumption of water are needed to maintain normal blood volume and circulation to the placenta.

People with certain conditions have been found to benefit from salt intake and should not follow a low-salt diet. Children with cystic fibrosis lose a large amount of salt in their sweat and thus should be encouraged to salt their food liberally. Chronic fatigue syndrome sufferers who have a form of low blood pressure triggered by changes in position (called orthostatic hypotension) have been reported to be helped by additional salt intake. Additionally, people with goitre or hypothyroid condition should not restrict intake of iodized salt if it is their only major source of iodine.

What do I need to avoid?

To avoid salt ask about ingredients at restaurants and others’ homes, and read food labels. The following list is not complete. Consult with a healthcare professional before making any significant changes to your diet.

Tinned soups, juices, and vegetables
Cereals: cornflakes, bran flakes
Cheese
Cottage cheese
Hydrolysed vegetable protein
Ketchup
Lite soya sauce
Microwave popcorn
Miso
Olives
Pickles
Processed meats: bologna, cured ham, frankfurters, etc.
Salad dressings (prepared)
Salted butter and margarine
Salted nuts
Seaweeds
Smoked or cured fish
Snack foods: potato chips, pretzels, tortilla chips
Soya sauce
Table salt
Worcestershire sauce

Best bets

Fresh foods such fruits, meats, vegetables
Oats
Packaged or prepared foods: look for labels stating “low-sodium,” “salt-free,” or “unslated”
Pasta
Rice
Seasonings and marinades such as dried herbs, garlic, lemon juice, and/or vinegar (in place of salt)

Are there any groups or books associated with this diet?

American Heart Association
1615 Stemmons Freeway
Dallas, TX 75207–8806
www.americanheart.org

The No Salt, Lowest-Sodium Cookbook: Hundreds of Favorite Recipes Created to Combat Congestive Heart Failure and Dangerous Hypertension by Donald A. Gazzaniga, New York: St. Martin’s Press, 2001

Get the Salt Out: 501 Simple Ways to Cut the Salt Out of Any Diet by Ann Louise Gittleman, New York: Crown Trade Paperbacks, 1996.

Cooking Without a Grain of Salt by Elma W. Bagg, New York: Bantam Books, 1998.

USDA Nutrient Database for Standard Reference (on-line search for sodium content)
www.nal.usda.gov/fnic/cgi-bin/nut_search.pl

Bibliography

Boles R, Rice DH, Hybels R, Work WP. Conservative management of Meniere’s disease: Furstenberg regimen revisited. Ann Otol Rhinol Laryngol 1975;84:513–7.

Brainard JB. Angiotensin and aldosterone elevation in salt-induced migraine. Headache 1981;21:222–6.

Carey OJ, Locke C, Cookson JB. Effect of alterations of dietary sodium on the severity of asthma in men. Thorax 1993;48:714–8.

De Lorenzo F, Hargreaves J, Kakkar VV. Pathogenesis and management of delayed orthostatic hypotension in patients with chronic fatigue syndrome. Clin Auton Res 1997;7:185–90.

Dengel DR, Hogikyan RV, Brown MD, et al. Insulin sensitivity is associated with blood pressure response to sodium in older hypertensives. Am J Physiol 1998;274:E403–9.

Dengel DR, Mayuga RS, Kairis GM, et al. Effect of dietary sodium on insulin sensitivity in older, obese, sedentary hypertensives. Am J Hypertens 1997;10:964–70.

De Stefani E, Oreggia F, Ronco A, et al. Salted meat consumption as a risk factor for cancer of the oral cavity and pharynx: a case-control study from Uruguay. Cancer Epidemiol Biomarkers Prev 1994;3:381–5.

Devine A, Criddle RA, Dick IM, et al. A longitudinal study of the effect of sodium and calcium intakes on regional bone density in postmenopausal women. Am J Clin Nutr 1995;62:740–5.

Donovan DS, Solomon CG, Seely EW, et al. Effect of sodium intake on insulin sensitivity. Am J Physiol 1993;264:E730–E734.

Evans CEL, Chughtai AY, Blumsohn A, et al. The effect of dietary sodium on calcium metabolism in premenopausal and postmenopausal women. Eur J Clin Nutr 1997;51:394–9.

Feldman RD, Schmidt ND. Moderate dietary salt restriction increases vascular and systemic insulin resistance. Am J Hypertens 1999;12:643–7.

Fogarty A, Britton J. The role of diet in the aetiology of asthma. Clin Exp Allergy 2000;30:615–27.

Franx A, Steegers EA, de Boo T, et al. Sodium-blood pressure interrelationship in pregnancy. J Hum Hypertens 1999;13:159–66.

Gomi T, Shibuya Y, Sakurai J, et al. Strict dietary sodium reduction worsens insulin sensitivity by increasing sympathetic nervous activity in patients with primary hypertension. Am J Hypertens 1998;11:1048–55.

Gotshall RW, Mickleborough TD, Cordain L. Dietary salt restriction improves pulmonary function in exercise-induced asthma. Med Sci Sports Exerc 2000;32:1815–9.

Grey A, Braatvedt G, Holdaway I. Moderate dietary salt restriction does not alter insulin resistance or serum lipids in normal men. Am J Hypertens 1996;9:317–22.

He J, Ogden LG, Vupputuri S, et al. Dietary sodium intake and subsequent risk of cardiovascular disease in overweight adults. JAMA 1999;282:2027–34.

Hughes J, Norman RW. Diet and calcium stones. Can Med Assoc J 1992;146:137–43 [review].

Javaid A, Cushley MJ, Bone MF. Effect of dietary salt on bronchial reactivity to histamine in asthma. BMJ 1988;297:454.

Jooseens JV, Geboers, J. Nutrition and gastric cancer. Nutr Cancer 1981;2:250–61.

Joossens JV, Hill MJ, Elliott P, et al. Dietary salt, nitrate and stomach cancer mortality in 24 countries. Int J Epidemiol 1996;25:494–504.

Knox GW, McPherson A. Meniere’s disease: differential diagnosis and treatment. Am Fam Physician 1997;55:1185–90, 1193–4 [review].

Lind L, Lithell H, Gustafsson IB, et al. Metabolic cardiovascular risk factors and sodium sensitivity in hypertensive subjects. Am J Hypertens 1992;5:502–5.

MacGregor GA, et al. Double-blind study of three sodium intakes and long-term effects of sodium restriction in essential hypertension. Lancet 1989;ii:1244–7.

Massey LK, Whiting SJ. Dietary salt, urinary calcium, and kidney stone risk. Nutr Rev 1995;131–9 [review].

McParland BE, Boulding A, Campbell AJ. Dietary salt affects biochemical markers of resorption and formation of bone in elderly women. BMJ 1989;299:834–5.

Medici TC, Schmid AZ, Hacki M, Vetter W. Are asthmatics salt-sensitive? A preliminary controlled study. Chest 1993;104:1138–43.

Moutquin JM, Garner PR, Burrows RF, et al. Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy. CMAJ 1997;157:907–19.

Muldowney FP, Freaney R, Moloney MF. Importance of dietary sodium in the hypercalciuria syndrome. Kidney Int 1982;22:292–6.

Nazario CM, Szklo M, Diamond E, et al. Salt and gastric cancer: a case-control study in Puerto Rico. Int J Epidemiol 1993;22:790–7.

Negri E, La Vecchia C, D’Avanzo B, et al. Salt preference and the risk of gastrointestinal cancers. Nutr Cancer 1990;14:227–32.

Pyykko I, Magnusson M, Schalen L, Enbom H. Pharmacological treatment of vertigo. Acta Laryngol 1988;455:77–81 [review].

Sabto J, Powell MJ, Gurr B, Gurr FW. Influence of urinary sodium on calcium excretion in normal individuals. Med J Austral 1984;140:354–6.

Saeed SR. Diagnosis and treatment of Meniere’s disease. BMJ 1998;316:368–72 [review].

Sakhaee K, Harvey JA, Padalino PK, et al. The potential role of salt abuse on the risk for kidney stone formation. J Urol 1993;150(2 pt1):310–2.

Sharma AM, Schorr U, Distler A. Insulin resistance in young salt-sensitive normotensive subjects. Hypertension 1993;21:273–9.

Silver J, Rubinger D, Friedlaender MM, Popovitzer MM. Sodium-dependent idiopathic hypercalciuria in renal-stone formers. Lancet 1983;ii:484–6.

Spencer JT Jr. Hyperlipoproteinemia, hyperinsulinism, and Meniere’s disease. South Med J 1981;74:1194–7,1200.

Stahle J. Medical treatment of fluctuant hearing loss in Meniere’s disease. Am J Otol 1984;5:529–33 [review].

Stamler J, et al. Findings of the international cooperative INTERSALT study. Hypertension 1991;17(Suppl I):I-9–15.

Steegers EA, Van Lakwijk HP, Jongsma HW, et al. (Patho)physiological implications of chronic dietary sodium restriction during pregnancy; a longitudinal prospective randomised study. Br J Obstet Gynaecol 1991;98:980–7.

Tsugane S, Tei Y, Takahashi T, et al. Salty food intake and risk of Helicobacter pylori infection. Jpn J Cancer Res 1994;85:474–8.

Tuyns AJ. Salt and gastrointestinal cancer. Nutr Cancer 1988;11:229–32.

van der Maten GD. Low sodium diet in pregnancy: effects on maternal nutritional status. Eur J Obstet Gynecol Reprod Biol 1995;61:63–4.

Zarkadas M, Geougeon-Reyburn R, Marliss EB, et al. Sodium chloride supplementation and urinary calcium excretion in postmenopausal women. Am J Clin Nutr 1989;50:1088–94.

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The information presented in the Food Guide is for informational purposes only and was created by a team of US–registered dietitians and food experts. Consult your doctor, practitioner, and/or chemist for any health problem and before using any supplements, making dietary changes, or before making any changes in prescribed medications. Information expires March 2007.

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