Aluminum compounds are added to table salt as an anticaking agent. Should we be concerned?
High quantities of aluminum are toxic and their accumulation in our bodies can contribute to various health issues, such as toxicity of the nervous system, the skeletal system and the hematopoietic system.
It is also associated with the Alzheimer’s disease, bone disease, such as osteomalacia, and anemia.
To determine whether the amount of aluminum contents in table salt has any impact on our health it is important to answer these two questions:
- Is the amount of aluminum in table salt relevant compared to the upper safe limit intake recommended by science?
- Is the amount of aluminum derived from table salt relevant compared to its contents of various foods?
Aluminum in our environment
The information below relates to a normal environment and overall population and not to extreme cases where aluminum levels in the environment may be dangerously high.
- What is the current daily intake?
Adults in the U.S. currently consume on average between 7–9 mg of aluminum. (3)
- What is the safe daily limit?
The safe limit of aluminum daily intake is set to 2mg per kg of body weight. (7)
The previous limit was set to 1mg per kg of body weight. This increase was based on no visible adverse effects of the 30mg/kg per body weight which includes a safety factor. (8)
For example, a 70kg person’s safe limit is 140mg daily.
- What happens to the excess aluminum?
Most of the excess aluminum that is ingested gets excreted by the body through the feces or urine. Only a small amount gets absorbed by the body and is located in the heart, spleen and bone. (7)
- What are the major food sources?
The amount of aluminum we take per day comes mainly from food ingredients, water and aluminum utensils used in the food preparation.
Aluminum intake varies between countries and regions and depends on dietary patterns, aluminum containing food additives and the frequency of usage of aluminum utensils. (9)
Foods with levels of aluminum below 5mg per kg are considered to have a low concentration. Most unprocessed foods have a low concentration of this metal.
On the other hand, many processed foods and some vegetables have high concentrations of aluminum, ranging between 5mg to 10mg of aluminum per kg. (10)
Food and water are the main contributors to the aluminum intake by the majority of the population. Certain foods contain higher than usual amounts of aluminum and represent the major source of exposure to this metal. Here is a list of foods with a high aluminum content: (11, 12, 13, 5)
– tea leaves, herbs, cocoa and spices;
– processed cheeses;
– non-dairy creamer;
– baking powders;
– grain products;
– dairy products;
– cake mixes;
– frozen doughs;
– pancake mixes;
– self-raising flours;
– pickled vegetables;
– vegetables such as mushrooms, spinach, radish, Swiss chard and lettuce.
- Is using aluminum utensils and foil safe?
Frequent usage of aluminum utensils and foil in food preparation is estimated to add an additional 2mg of aluminum to the western diet.
However, these statistics can vary from country to country. For example, in China, where the usage of aluminum utensils is higher, the estimated aluminum intake from utensils is about 4mg per day. (14)
Taking into consideration the safe daily limit of 2mg of aluminum per kg of body weight, this increase shouldn’t pose health issues. (7)
- Are some medications high in aluminum?
There are some medications with high aluminum contents: – some antacids may raise the daily aluminum intake by 10 to 100 times; (7)
– buffered aspirins;
– antidiarrheal products;
– douches and;
– hemorrhoidal medications.
Check the list of drugs containing aluminum-hydroxide here.
- How much aluminum we breathe in from the air?
Overall, the inhaled amount of aluminum is negligible in comparison with food, even from polluted air. From unpolluted air, we intake less than 2mcg (0.002mg) of aluminum per day.
On the other hand, from industrial, polluted air the level of daily aluminum intake could be as high as 124 mcg (0.124 mg) per day. (7)
- How much aluminum do we ingest from water?
From fresh, untreated water the aluminum intake is less than 0.001-1mg per liter.
However, higher amounts are found in some regions reaching 26mg per liter.
Treated water contains a small amount of aluminum sulphate, which effectively removes parasites but also increases the overall amount of aluminum in water.
In the U.S. the overall average of aluminum contents in water treated with aluminum sulphate is 0.16 mg per liter.
The amount varies, though, between 0.01 to 1.3 mg per liter, depending on the treatment plant. (15)
In Europe, treated water usually contains less than 0.2 mg of aluminum per liter. (7)
Aluminum in table salt
Aluminum is used as a component of the most common anticaking agent used in table salt, the “sodium aluminosilicate” known as “food additive E-554”. (16)
Strict government regulations only allow less than 2% of this compound to be added to table salts.
- How much aluminum does this compound actually contains?
The chemical formula for sodium aluminosilicate is AlNa12SO5.
Using the online molecular calculator, you can see that the aluminum content weight only 6.5% of the whole compound.
If we consider that 2% is the maximum amount of this anti-caking agent allowed in salt, then 1 gram of salt would contain 20mg of sodium aluminosilicate, which in turn contains 1.3mg of aluminum.
- How much table salt do we have per day?
From current statistics we consume on average 8,500mg of salt per day. (read more..)
About 75% of this amount comes from processed foods, 12% naturally occurs in the whole foods and 13% is added at the table or while cooking. For this myth question only 13% of the 8,500mg (1,100mg=1.1g) of salt is relevant since only this portion of daily salt intake contains aluminosilicate.
Provided that you only sprinkle table salt and not a gourmet salt (which doesn’t contain this anti-caking agent) while cooking or at the table, the following formula shows how much aluminum we actually ingest through table salt per day.
8,500mg x 0.13 x 0.02 x 0.065 = 1.4 mg of aluminum.
For clarity, the following are the components of the equation:
8,500mg: the average amount of salt we consume per day;
0.13: out of all the salt consumed per day, 13% corresponds to table salt;
0.02: maximum amount of the additive sodium aluminosilicate allowed in salt;
0.065: the amount, per weight of aluminum in sodium aluminosilicate.
- The upper safe limit of aluminum is 2mg per kg of bodyweight. Therefore, a safe amount per day for a 70kg person is below 140mg. As presented below, only 1.4mg comes from table salt which is 100 times less than the upper limit. This makes table salt with aluminosilicate completely safe.
- We consume daily between 7 and 9mg of aluminum from food and water. If we use only table salt with aluminosilicate added for cooking and sprinkling on our food at the table, the amount of that salt would be around 1.1g which contains only about 1.4mg (only about 15% of overall intake from food).
- If you have concerns about aluminum toxicity from your diet or the environment, locate and eliminate the major contributors of this metal. Otherwise, there is no reason of concern.
NUTRITION FACTS VS NUTRITION MYTHS
You will find a summary of the most common nutrition myths and evidence-based nutrition facts here.