ON THIS PAGE
- Background information on sodium intake
- Why don’t we worry about over-consuming other minerals?
- What are the main sources of sodium in our diets?
- What is the official recommended daily sodium intake?
- How much sodium per day do we consume?
- Mainstream point of view on sodium intake
- Low sodium intake is dangerous - emerging of new scientific evidence
- Final tips on daily sodium intake
Background information on sodium intake
When we talk about salt consumption, it usually refers to the sodium intake.
It constitutes between 34%-39% of the salt, depending on the type. The rest is mostly chloride and tiny amounts of some trace minerals.
Sodium is an essential mineral for our survival. However, since sodium is readily available as an isolated mineral compound (sodium-chloride i.e. salt), which we can simply buy and add to our food, there is a danger of over-consumption.
More importantly, the amount of sodium added to most processed foods accounts for about 75% of our overall sodium consumption. This is, of course, taking into account an average population. Those who mostly use whole foods and avoid processed products would not fall into this category.
It has long been established and uniformly agreed that:
- High blood pressure increases the risk of heart attacks and strokes;
- Higher intake of salt causes an increase in blood pressure.
What the studies on this subject do not agree on or do not show clearly is the correlation between salt intake and stroke or death caused by cardiovascular complications. More studies are necessary to resolve this issue.
We currently consume an average of 3,400mg of sodium per day:
- 75% of it comes from processed foods,
- 12% occurs naturally in food and
- 13% we add at the table for extra taste.
Global consumption (from a study with 66 countries) was estimated to be between 2,180mg and 5,510mg of sodium per day. (1)
Why we don’t worry about over-consuming other minerals?
If other minerals were as readily available and as satisfying to the palate as sodium, we would be sprinkling Iron or Selenium powder in our food too, with disastrous consequences.
Other minerals, however, are obtained from food (in more or less balanced amounts) and, in more concentrated forms, from tasteless food supplements.
Therefore, toxicity from these other minerals usually occurs when consuming too much of one type of food (such as Brazil nuts) or taking too much of one particular supplement, especially when not required.
Due to the way that it is present in our diet, the consumption of salt needs to be controlled more than other minerals.
What are the major sources of sodium in our diets?
|Processed foods: ready products you buy from the shelf, restaurants.||Naturally occurring sodium in whole foods||Added salt during food preparation|
Products richest in sodium include: bread, cheese, ready to eat products off the shelf, sauces, breakfast cereals, crisps, potato products, restaurant meals, fermented products and some seafood products (e.g. seaweed). (read more..)
You more likely consume a “healthy” amount of salt if you eat mostly whole foods prepared at home.
What is the officially recommended daily sodium intake?
The answer to this question is not simple due to conflicting information between dietary guidelines established by most governments and health organizations and newly emerging evidence.
If you trust the guidelines, the ideal sodium intake is somewhere between an adequate intake of 920mg and an upper limit of 1,500mg of sodium per day. The absolute maximum is 2,300mg per day.
If you find the newer studies more convincing, you might stick to the higher range of about 2,600-5,000mg of sodium per day.
How much sodium per day do we consume?
|By age and gender||mg of sodium/day||mg of sodium/day|
|70 and over||3,328||2,526|
|General averages||mg of sodium/day|
|Adults by ethnicity|
|Region||mg of sodium/day|
Mainstream view point on daily sodium intake
If you are not an athlete who requires more sodium, or suffer from a specific condition in which sodium intake must be limited, according to most governmental and health organizations (see table below) you should be consuming between an “adequate intake” amount of 920mg of sodium and the upper safe limit of 2,300mg daily, preferably being reduced to 1,500mg or below for optimal benefit.
Here are the results of some major studies regarding this subject
- A large systematic review and meta-analysis study has shown various health benefits of sodium reduction: a high quality evidence that blood pressure gets reduced; moderate quality evidence that there is no negative impact on blood lipids, catecholamine levels or renal function and that there is an association of lower sodium with the reduced risk of stroke and fatal coronary heart disease in adults. (4)
- A large study by INTERSALT demonstrated a modest increase in blood pressure with higher sodium intake. (5)
- A study that included 18 countries showed that the blood pressure was higher in those people who were ingesting more than 6,000mg of sodium per day, modest between 3,000mg and 5,000mg and insignificant for those that ingested less than 3,000mg per day. (6)
- A long term Cochrane systematic review recommends that a reduction from 9g-12g to 5g-6g of salt per day will drastically reduce the blood pressure and that reduction to 3g of salt per day guarantees an optimum blood pressure.
- Meta-analysis of randomised trials showed that a reduction of sodium and an increase in potassium intake in people with hypertension resulted in a blood pressure decrease. (8)
Emerging of new evidence that low sodium intake is dangerous
In the last decade, new studies have been attempting to show that the mainstream recommendations of sodium intake do more harm than good to our health.
These studies claim that there is not enough evidence that sodium amounts consumed at a current intake rate of 3,400mg per day are harmful.
They present results showing that the healthiest range of sodium intake is actually between 2,600mg and 5,000mg per day (much more than current mainstream recommendations).
The authors of the above study argue that these conclusions are consistent with the recent discoveries in neuroscience which show that our bodies (in particular, neural circuits in animals’ vertebrae) regulate sodium appetite within the narrow physiologic range.
In other words, the amount of sodium we consume on average per day is what our body needs and therefore the amounts we currently consume are correct.
This, however, in my opinion is not valid reasoning since we have a tendency to develop a taste for salt, meaning that by getting accustomed to processed foods we artificially increase the salt intake.
If our diets consisted mostly of whole foods, it is possible that our taste for salt would drop naturally and salt added at the table would make up for what our bodies need.
The following studies show contradictory results to the mainstream guidelines, some of which are accompanied with the published peer criticism.
- According to the American Diabetic Association lowering the intake of sodium increases the risk of all-cause and cardiovascular mortality in type 1 and type 2 diabetics and patients with an end-stage renal disease (ESRD). (9, 10)
- A recent survey showed that a lower sodium intake (<2,300mg per day) is related to an increased risk of mortality related to cardiovascular diseases. (11, 12)
- A recent cohort study has shown that a lower intake of sodium is associated with a higher risk of cardiovascular related mortality (13)
However, the study was heavily criticised for its methodological flaws. (14, 15, 16)
One of the criticised methods was that the sodium measurement used excreted urine over 24 hours which is not an accurate measurement (e.g. over 3 days gives more precise results). (17)
- Another study claims that the current mainstream recommendations are associated with an increased risk of cardiovascular related mortality and hospitalisation.
The study showed that the risk of death due to cardiovascular complications increases if the sodium excreted via urine is not within the range of 4,000mg and 6,000mg per day.
The excretion of more than 7,000mg of sodium per day showed an increase of risk of death by 1.15 times and the excretion of less than 3,000mg per day showed an increase of 1.27.
Excreted sodium in urine is approximately equivalent to ingested sodium, although there are more precise results if the measurement is done over 72 hours rather than 24 as in the case of this study which was one of the reasons it was criticised by peers. (18, 19)
- Measurements across 66 countries and using 205 studies, have shown that the lowest risk for mortality from cardiovascular complications occurs when the consumption of sodium is between 3,000mg and 6,000mg daily.
An intake of more than 6,000mg or less than 3,000mg was associated with an increased risk. (1)
- A study showing that a low sodium diet significantly increases the rate of cardiovascular complications and death due to heart failure. (20)
Here are other related readings:
- The (Political) Science of Salt (by Gary Taubes)
- Blood pressure, cardiovascular outcomes and sodium intake, a critical review of the evidence. (by Stolarz-Skrzypek K, et al.)
- Making Sense of the Science of Sodium. (by Heaney RP)
The following table shows a summary of recommendations from various sources:
|Ranges of sodium||mg per day||Sources|
|Minimum limit||200-500||Studies (1, 2)|
|Upper Limit for people in a risk group (70% of U.S. population): (3)|
- People 40 years old or over,
- African Americans,
- People with high blood pressure,
- Diabetics or
- People suffering from chronic kidney disease.
|1,500||NHMRC , USDA, AND, ADA, AHA|
|Upper limit||2,300||NHMRC , USDA, AND, ADA|
|Upper limit||4,945||Recent studies (4)|
|Ideal daily intake||<1,500||ADA, AND, AHA|
|Ideal daily intake||2,645–4,945||Recent studies (4)|
|The toxic dietary dose of sodium||200mg-400mg per kg of body weight||Medicine and Biology (5)|
|Fatal dose of sodium||400mg-1,200mg per kg of body weight||Medicine and Biology (5)|
FDA – U.S. Food and Drug Administration (23)
USDA – United States Department of Agriculture (24)
AHA – American Heart Association (27)
NHMRC- National Health and Medical Research Council (Australia and New Zealand) (28)
Final tips on daily sodium intake, based on all available studies
In light of the new studies and the conflicting results they present, I consider that the following solution for sodium intake is the safest:
- Eliminate or reduce to a minimum the processed food intake.
This will not only cut down on the excessive amounts of salt, but also the other ingredients that adversely affect your health, such as sugar, preservatives and many others.We develop a taste preference for salt.
Therefore, the appetite for sodium is higher in people whose diet consists of processed and salty foods. The more salty chips you eat the less sensitive you are to salt and the more sodium you need for the food to taste satisfactory.
However, the good news is that by eliminating or substantially reducing the amount of processed foods consumed, you will develop a heightened sensitivity to saltiness within just couple of months, achieving the same pleasure from food as when you were on a high salt diet.
- Consequently to the above consume mostly whole food.
Cook more at home using whole ingredients and add salt when you feel you need it. Once the processed foods are cut down and your taste for salt is back to its natural state, your body will tell you if you need more or not. When you get to that stage, you won’t need to make more extreme restrictions.
In addition, if your aim is specifically to reduce blood pressure, see “How to reduce blood pressure”.
NUTRITION FACTS VS NUTRITION MYTHS
You will find a summary of the most common nutrition myths and evidence-based nutrition facts here.