The Selenium
The Magdalena River Nuts a natural source of selenium a fundamental trace element for humans.

The Magdalena River Nuts a natural source of Selenium an essential trace element for the human being.

The natural origin is a primary feature in the products we use as food, it is considered that vitamins and trace elements are more valuable if they come from a natural source.

The tree from which these nuts come: Lecythis Minor, is part of the species Lecythis (MORI 1990) this species has an interesting feature: Selenium accumulate in the seeds do grow in Seleniferous soils, we find these wild soils on the banks of the Magdalena River, mythical , ancestral and millennial Rio, which covers a large part of the Colombian geography in more than 1,500km, reaching its mouth in the Caribbean Sea, this species develops wildly reaching several communities, where we play a fundamental role for the development of them and allows us to reach the precious fruit of these trees: the Magdalena River Nuts.

¿Why and how does Selenium present in the soil end up in the seed s of Magdalena River Nuts trees?

Selenium is actually an element which is detrimental to most plants. They absorb the selenium from the soil as selenate and process it in analogy to the common biochemical pathway of sulphur. Most plants cannot differentiate between selenium and sulphur and therefore incorporate selenium at random instead of sulphur into amino acids: They synthesise instead of cysteine to a certain degree selenocysteine and instead of methionine selenomethionine. Most plants do also not differentiate between normal sulphur containing amino acids and these seleno analogs and thus incorporate them in random substitution of the sulphur analogs into proteins (DAWSON, 1988). .

There are certain differences between sulphur amino acids and selenium amino acids: The selenium atom is larger and - more important - it behaves chemically somewhat differently. The Se H bond in selenocysteine is more acidic (that is, it ionises at lower pH) than the S-H bond; also it is more prone to oxidation. Thus, in proteins Se-H groups form readily -Se-Se- crosslinking bridges. These, together with the higher degree of ionisation contorts proteins and makes them from a certain Se concentration on dysfunctional: The organism - be it plant or animal - dies if it has absorbed too much selenium (HUBER, 1967). Selenium accumulator plants have found a solution for this dilemma.

They interrupt the normal biochemical pathway of selenium metabolism at a precursor of the seleno amino acids, namely selenocystathionine (ARONOW, 1965): HOOC-CH(NH2)-CH2-CH2-Se-CH2-CH(NH2)-OOH.

La ventaja de este compuesto es que (como la cisteína es análogo de azufre) no se incorpora en proteínas, Por lo tanto, las proteínas no pueden dañarse.

The advantage of this compound is that it (like the sulphur analog cystathionine) is not incorporated into proteins. Thus, proteins cannot be damaged. Rather, the uncommon amino acid is "compartmentalized" in certain parts of the plant in the free form rendering these parts less attractive to browsing animals. Selenium is thus used as a protective agent. And the selenium accumulator plants can thrive on seleniferous soils unlike all other plants.

The importance of an adequate nutritional selenium intake

Selenium is essential for human and animal nutrition. It occurs in the body in appr. 35 proteins, generally in the form of seleno-cysteine. Many of the proteins are enzymes (glutathione peroxidases, iodothyronine deiodinases, thioredoxine reductase), the function of others (Selenoprotein P, Selenoprotein W) is unknown, they may simply be storage forms. Non-proteinaceous selenium occurs in form of certain metabolites (e.g.selenodiglutathione) which do also have an important function. Selenium is further found in low concentration in all (e.g. muscle) proteins where methionine (and probably also cysteine) is randomly substituted by the seleno analogs selenomethionine (and selenocysteine).

Selenium is not evenly distributed in the body. In times of deficiency the element is rapidly lost from muscle and liver and retained in brain, endocrine and reproductive organs, apparently because it is essential for the functioning of these organs. Even within organs certain selenoenzymes are expressed with preference over others in periods of under-supply (McKENZIE, 2002, p. 234).

¿How much selenium intake is sufficient?

LEVANDER and MORRIS (1984) determined the dietary selenium requirement to maintain a balance to be 80 mcg per person per day for men and 57 mcg for women or 1 mcg/kg body weight in general. At equilibrium, excretion equals intake. Is this balance requirement an optimal value? It is rather a minimum value, if the results of certain intervention studies are considered, e.g. of CLARK (1996).

Cancer incidence reduction was observed at supplementation rates of 200 mcg Se per person per day. Apparently, higher intake while leading to higher excretion involves also an increased selenium metabolism. And selenium metabolites are assumed to play a critical role in cancer prevention (McKENZIE, 2002, p. 245). The upper limit of selenium intake (long term level of no adverse effect) was stated by COMBS & COMBS (1986) to be 775 mcg organically bound and 550 mcg of inNatural Selenium per person per day. According to SPALLHOLZ (1990) adverse effects can be observed at intakes above 400 mcg Se per person per day already. Therefore, considering the amount of selenium already present in the common diet and applying a safety margin, selenium supplements should not be consumed over longer periods at rates of more than 200 mcg per person per day.

¿What are the effects of dietary selenium?

Selenium detoxifies mercury by formation of a mercury selenide protein complex (SCHRAUZER). It also reduces the toxicity of cadmium (PARIZEK 1971) and arsenic (WANG 2001). Selenium diminishes the coronary infarction risk, already at fairly low supply rates (45 mcg per person per day). Therefore the preventive effect of selenium supplementation becomes visible only in populations with a low average dietary selenium intake (e.g. Finland, New Zealand, Germany).

This observation is explained by the hierarchy of selenium usage: In Se deficiency the more vital organs retain selenium in preference to others. (HUTTUNEN 1997, KARDINAAL 1997). KIEM (1987) states that no human cell has a higher selenium concentration than blood platelets and he found that they retain selenium firmer than other blood components under conditions of depletion. Most striking is the effect of selenium supplementation in the prevention of cancer.

CLARK (1996) reports a 50% reduction of cancer incidence in a double blind prevention study in which half of the participating patients were administered 200 mcg selenium while the other half obtained placebos (all patients had a previous cancer history). The effect of selenium became strikingly visible at an early stage: "Primarily because of the apparent reductions in total cancer mortality and total cancer incidence in the selenium group, the blinded phase was stopped early". Crucial for the prevention effect seem to be certain selenium metabolites, e.g. selenodiglutathione. This compound does not harm normal cells but causes apoptosis of tumor cells by inducing the tumor suppressor protein, p53 (LANFEAR 1994).

Selenium modulates immunity

Se deficiency impairs immunity, Se intakes above those habitually consumed in many Western countries boost immunity and high Se intakes lead to toxic effects and suppression of immunity" (McKENZIE 2002, p.229). The influence of selenium on the immune system has many facets. Only one function shall be mentioned, the role of selenium, or rather the selenoenzyme glutathione peroxidase in the so-called "respiratory burst". The respiratory burst is a rapid generation of reactive oxygen species (ROS), most of all superoxide (O2-.) which certain lymphocytes direct against invading microorganisms to destroy them. For the optimal function of the respiratory burst a sufficient concentration of the glutathione peroxidase is decisive and indispensible. Hydrogen peroxide generated in the process threatens to damage other cell functions and most of all it blocks the enzyme which provides the superoxide in the first place. The respiratory burst cannot start unless the hydrogen peroxide is removed. The removal of the hydrogen peroxide is effected by glutathione peroxidase which thus initiates and controls the entire process. (TRENAM, 1992; SPALLHOLZ, 1990).

¿Is Natural Selenium superior to inNatural Selenium?

From an aesthetic point of view organic forms are always preferable to inorganic forms. While inorganic forms (selenate and selenite) are effective and are used extensively in animal feed, especially selenite has many disadvantages. Its higher reactivity promotes other undesirable reactions: Ascorbate reduces selenite to insoluble and in absorbable elemental selenium. According to SCHEARER (1980) selenite causes cataracts in young rats, probably because of its promotion of peroxidation.
The general instability of selenite explains the inferior uptake and retention in comparison to organic forms of selenium (WHANGER 2002).

Selenocystathionine, the form of selenium in Magdalena River Nuts has many advantages as a nutritional selenium form. Its comparatively large molecule protects the selenium and diminishes the likeliness of unwanted side reactions as for instance oxidation.
As a non-proteinaceous amino acid the compound is easily integrated into the physiological pathways of selenium metabolism without prior incorporation into body proteins.

From the Magdalena River Nuts we extract the MAGNUT FLOUR with more than 1,000ppm of natural selenium and the MAGNUT Sense 100% Natural Oil available as raw materials for the production of nutritional supplements, nutraceuticals, vitamins and oil with ample benefits for the skin car and the elaboration of cosmetic products.