Dietary sulfur is an essential component
Food sulfur is an ORGANIC component naturally present both in food and in the human body (about 140g). This is a PLASTIC element, as it forms part of the sulfur amino acids : methionine , cysteine and cystine; it is therefore also present in glutathione , coenzyme A, thiamine (vit. B1), biotin ( vit H ) and insulin .
Chemical structure of cystine, a sulfur-containing amino acid
Furthermore, sulfur and the elements that contain it participate in the constitution of connective tissue , mucopolysaccharides and bile acids . An organic sulfur supplement, methylsulfonylmethane or MSM , is therefore proposed in the treatment of osteoarthritis .
Food sulfur is absorbed in the small intestine while the main elimination routes are urine and faeces . The deficiency conditions are rare and the same applies to the excess, which is likely to cause disturbances of the physical development and failure to thrive.
Food sources of sulfur are mainly foods of protein origin (eggs, meat , fish and cheeses ), while in the form of sulphates they can be introduced with drinking water and fruit and vegetables.
Sulphates: toxic compounds of the atmosphere and contaminated food
Sulphates are INORGANIC compounds NOT NATURALLY present in food and their excessive concentration can be extremely harmful to human health.
Sulfates become toxic if they reach excessive concentrations; often these are the result of the sum of the pollutants and the sulphates regularly usedfor technological processing; polluting sulphates can end up on food from atmospheric air or through polluted rains (acid rain), while the application of sulphates useful for food processing is subject to specific regulations for their use. Unfortunately, although regulated, the latter do not take into account the overall sulphates introduced, therefore their intake with the diet should still be limited.
Overall, sulphates derive mainly from:
- Coalsmoke (SO 2 H 2 S)
- Combustion of oil (SO 2, H 2 S)
- Sulfuric acid from industrial smog (H 2SO 4 ) and its lead salts (PbSO 4 )
- Food processing processes such as dehydrationof fresh fruit (which uses sulfur to preserve color and some nutrients ; manganese sulphate MnSO 4 )
- Foods, additivesand drugs treated with sulfuric acid: saccharin , aspirin , alum (aluminum sulphate and potassium dodecahydrate KAl (SO 4 ) 2 12 H 2 O, also known as potassium alum, is used in the industrial preparation of pickles and cherries in spirit)
- Purification of watertreated with copper sulphate (CuSO 4 )
- Use of insecticidesbased on tribasic copper sulphate
- Sulfonamidedrugs (sulfonamides with a group characterized by a sulfur atom at valence 6; R-SO 2 -NH 2 )
- Purganti saline: magnesium sulfate (MgSO 4 )
- Raising food additives(sulphates of: sodium , potassium , calcium , aluminum, aluminum and sodium , aluminum and potassium, aluminum and ammonium)
- It is important not to confuse the sulphates (so far described) with the food additives based on SULPHITES(SO 3 2- ) and SULFUR DIOXIDE ; the latter are preservatives generally contained in wine , drinks, fish, dried fruit, etc.
More information on sulphites can be found in this article .
Toxicity of sulphates
Excessive amounts of sulphates in foods can lead to a copper deficiency, which would otherwise be sufficient to meet normal physiological needs.