The human minimum requirement for sodium in the diet is about 500 mg per day, which is typically less than one-sixth as much as many diets "seasoned to taste". For certain people with salt-sensitive blood pressure or diseases such as Ménière's disease, this extra intake may cause a negative effect on health.
A low sodium diet has a useful effect to reduce blood pressure, both in people with hypertension and in people with normal blood pressure. Taken together, a low salt diet (median of approximately 4.4 g/day – approx 1800 mg sodium) in hypertensive people resulted in a decrease in systolic blood pressure by 4.2 mmHg, and in diastolic blood pressure by 2.1 mmHg.
Advising people to eat a low salt diet, however, is of unclear effect in either hypertensive or normal tensive people. In 2012, the British Journal Heart published an article claiming that a low salt diet appears to increase the risk of death in those with congestive heart failure, but the article was retracted in 2013. The article was retracted by the journal when it was found that two of the studies cited contained duplicate data that could not be verified.
A doctor might prescribe a low sodium diet for patients with diabetes insipidus.
A 2021 Cochrane review of controlled trials in people with chronic kidney disease at any stage, including those on dialysis, found high-certainty evidence that reduced salt intake may help to lower both systolic and diastolic blood pressure, as well as albuminuria. However there was also moderate certainty evidence that some people may experience hypotensive symptoms, such as dizziness, following sudden sodium restriction. It is unclear whether this affects the dosage required for anti-hypertensive medications. The effect of salt restriction on extracellular fluid, oedema, and total body weight reduction was also uncertain.
Food and drink contents
Sodium occurs naturally in most foods. The most common form of sodium is sodium chloride, which may be found sold as — depending on the size and shape of the salt crystals — table salt, sea salt, and kosher salt, among others. Milk, beets, and celery also naturally contain sodium, as does drinking water, although the amount varies depending on the source. Sodium is also added to various food products. Some of these added forms are monosodium glutamate (MSG), sodium nitrite, sodium saccharin, baking soda (sodium bicarbonate), and sodium benzoate.
Because large amounts of salts are given out by regenerative water softeners, over 60 cities in Southern California have banned them because of elevated salt levels in ground water reclamation projects. Water labeled as "drinking water" in supermarkets contains natural sodium since it is usually only filtered with a carbon filter and will contain any sodium present in the source water.
High sodium content
Condiments and seasonings such as Worcestershire sauce, soy sauce, onion salt, garlic salt, and bouillon cubes contain sodium. Processed meats, such as bacon, sausage, and ham, and canned soups and vegetables are all examples of foods that contain added sodium. Fast foods are generally very high in sodium. Also, processed foods such as potato chips, frozen dinners and cured meats have high sodium content.
Low sodium content
Unprocessed, fresh foods, such as fresh fruits, most vegetables, beef, poultry, fish and unprocessed grains are low in sodium. Low– or no–sodium products, and corresponding versions of products otherwise high in sodium, can be found in stores as well as online. Salt substitutes such as potassium chloride may be used to provide a similar taste to salt while reducing sodium intake, and flavor additives such as monosodium glutamate can help reduce sodium intake by enhancing other flavors.
Other foods that are low in sodium include:
- Seasonings: Black, cayenne, or lemon pepper, mustard, some chili or hot sauces
- Herbs: Dried or fresh garlic, garlic/onion powder (no salt), dill, parsley, rosemary, basil, cinnamon, cloves, paprika, oregano, ginger, vinegar, cumin, nutmeg
- Most fresh fruits and vegetables, exceptions include celery, carrots, beets, and spinach
- Dried beans, peas, rice, lentils
- Macaroni, pasta, noodles, rice, barley (cooked in unsalted water)
- Honey, sugar
- Unsalted butter
- Unsalted dry curd cottage cheese
- Fresh beef, pork, lamb, fish, shrimp, egg
- Milk, yogurt
- Hot cereals/Porridge
- Club soda, coffee, seltzer water, soy milk, tea
- Diabetes insipidus
- Health effects of salt
- Health Canada Sodium Working Group
- List of diets
- Heart Failure Society of America, How to follow a low sodium diet
- Implementing recommendations for dietary salt reduction: Where are we? DIANE Publishing. ISBN 1428929096.
- He, FJ; Li, J; Macgregor, GA (30 April 2013). "Effect of longer-term modest salt reduction on blood pressure". The Cochrane Database of Systematic Reviews (4): CD004937. doi:10.1002/14651858.CD004937.pub2. PMID 23633321.
- Adler, AJ; Taylor, F; Martin, N; Gottlieb, S; Taylor, RS; Ebrahim, S (18 December 2014). "Reduced dietary salt for the prevention of cardiovascular disease". The Cochrane Database of Systematic Reviews (12): CD009217. doi:10.1002/14651858.CD009217.pub3. PMC 6483405. PMID 25519688.
- Dinicolantonio, JJ; Pasquale, PD; Taylor, RS; Hackam, DG (Jan 24, 2013). "Low sodium versus normal sodium diets in systolic heart failure: systematic review and meta-analysis". Heart. doi:10.1136/heartjnl-2012-302337. PMID 22914535. (Retracted, see doi:10.1136/heartjnl-2012-302337ret, PMID 23640983)
- Marcus, Adam (2 May 2013). "Heart pulls sodium meta-analysis over duplicated, and now missing, data". Retraction Watch. Retrieved 2013-09-29.
- McMahon, Emma J; Campbell, Katrina L; Bauer, Judith D; Mudge, David W; Kelly, Jaimon T (2021-06-24). Cochrane Kidney and Transplant Group (ed.). "Altered dietary salt intake for people with chronic kidney disease". Cochrane Database of Systematic Reviews. 2021 (6). doi:10.1002/14651858.CD010070.pub3. PMC 8222708. PMID 34164803.
- Sodium, Your Health, and Your Drinking Water by Gene Shaparenko, Aqua Technology Water Stores
- NIH Medline Plus Medical Encyclopedia
- Lubin, Gus (2 February 2017). "Everyone should cook with MSG, says food scientist". Business Insider. Retrieved 27 January 2019.
- Sodium: Are you getting too much? Mayo Clinic