Trace elements are among the mineral salts, non-energy nutrients that are nonetheless essential. They are opposed to macroelements, such as calcium, because they are present in the human body in much smaller quantities, of the order of a few grams for iron or fluorine, or even less than 1 mg for chromium and cobalt.
Research on trace elements is far from complete. For some, dosing techniques and modes of action have only just been perfected. Trace elements can have a structural role: for example, iron in hemoglobin, and iodine for thyroid hormones. Most help activate all kinds of enzymes. Finally, certain trace elements contribute to antioxidant defences.
On the front line against cellular aging
Selenium, zinc, copper, iron and manganese are part of the group of antioxidants. To neutralize free radicals and thus participate in the prevention of cardiovascular diseases and certain cancers, they act in synergy with vitamins E and C, beta-carotene and polyphenols.
Zinc is also involved in immune defences, iron is anti-anaemic.
In which foods are trace elements found?
- the selenium concentrates in fish and seafood, it is also found in eggs.
- the ironthe zinc and the copper, present in offal and meat, are particularly well assimilated. In addition, it is found in pulses and whole grains.
- the manganese is abundant in plants and tea.
- the fluorine is essential to the strength of tooth enamel, it participates in the prevention of cavities. To have your quota, it is advisable to choose drinking water providing about 1 mg of fluoride per litre.
- I’iodine indirectly contributes to weight stability, as it is a constituent of thyroid hormones that regulate energy metabolism. It is provided by fish, seafood, eggs, dairy products and iodized salt.
- the chromium and manganese are essential for the production or action of insulin. In case of deficiency, there is a dysfunction of this hormone, which results in excessive storage of fat. We fill up on chromium by eating eggs, liver, and whole grains.
Other trace elements have been identified in the human body: molybdenum and boron, which participate in protein metabolism; lithium, important for nervous balance and silicon, which intervenes in the synthesis of collagen.
In the current state of knowledge, for lack of deficiencies identified in humans, not all trace elements benefit from the recommended intake. Experts believe that “food satisfies the body’s needs”. A good reason to eat varied and balanced!
Food supplements: respect the quantities
As for dietary supplements, they should come to the rescue only on the advice of a doctor or dietitian. Because they are beneficial in nutritional doses, many trace elements are harmful in excess. For most there is a safety limit: an intake not to be exceeded, which may only be around twice the recommended intake.