Sodium-rich foods
Distinguishing foods low in sodium from those that contain good quantities of it is not a complicated undertaking; sodium is an almost ubiquitous trace element, therefore its dietary intake with food is sufficient to cover the recommended human requirement . However, in our country the common tendency is to exceed the dietary sodium intake through the abuse of sodium chloride (NaCl), or table salt , inexorably altering the general state of health of the population.
To distinguish foods on the basis of the amount of sodium they contain, it is sufficient to group them into two categories:
- Fresh foods: foods low in sodium
- Preserved, processed or otherwise added foods: foods rich in sodium
Chemically, table salt is the result of the crystallization of sodium (Na + ) associated with chlorine (Cl – ).
Salt as a preservative
The main feature of sodium chloride is its shelf life potential, therefore its addition to foods increases the hygienic wholesomeness of foods on two fronts:
- Inhibits the proliferation of contaminating organisms (although not all and not as effectively)
- It drastically reduces the percentage of free water (Activity Water – AW) responsible for the pathogenic proliferation and the spontaneous enzymatic degradation of the food
In ancient times, the discovery of salting for food preservation favored the population increase thanks to the temporal distribution of the consumption of meat and fish , and the reduction of food poisoning . However, these behaviors have also influenced the collective habit of salty tastes , limiting the natural perception of foods and promoting the consumption of preserved products; to date, foods naturally low in sodium are commonly added with table salt to enhance their flavour.
Sodium requirement
Adult subjects keep their metabolic functions active through the intake of 69-460 mg/day of sodium, but taking into account individual variability (loss through sweating , faecal excretion and urinary excretion) it is recommended to introduce about 575 mg/day . The natural food content of sodium in fresh foods would be sufficient on average to meet the individual needs of this trace element.
Sodium deficiency is very rare, as well as exclusive of pathological pictures such as renal insufficiency , chronic diarrhea and trauma ; on the contrary, excessive sodium intake causes an increase in extracellular fluids causing:
- The appearance of tissue edema
- The occurrence of arterial hypertension
- Aggravation of panniculopathy (commonly called cellulite )
Excess table salt also acts negatively on gastric acid secretion and can promote complications of the mucosa . However, acute toxicity from food-borne sodium is at least unlikely.
High and low sodium foods
Low-sodium foods, as anticipated, are all fresh ones with no added salts; on the other hand, the foods that are rich in it are:
- The whole category of dehydrated foods with salt ( cod ; anchovies , sardines and salted herring ; raw ham , speck , lonzino, capocollo etc.)
- The entire category of foods ground, kneaded or mixed with salt (all cured meats : salami , mortadella , ciccioli , soppressa, finocchiona, sausages , cotechino , etc.; cheeses )
- The entire category of foods in brine or cooked in salted water and then canned ( canned beans , natural tuna , tuna in oil , canned vegetables , etc.)
- All foods added with sodium glutamate ( bouillon cube and ready meals) and sodium bicarbonate .
NB. CATCHED (not farmed) fishery products , especially bivalve molluscs ( mussels , clams , etc.), contain a fair amount of sea water; in a general context of moderate sodium intake and in the absence of pathologies, they are not a problem, on the contrary it is advisable to cook and serve them without the cooking fluid .
