Manganese- An Essential Element

Humans need manganese, although this was only realized in the 1950s, perhaps because the requirement is so modest. (1) Some of the health benefits of manganese include helping promote healthy bone structure, bone metabolism, and creating essential enzymes for building bones. It also acts as a co-enzyme to assist metabolic activity in the human body. Apart from these, there are other health benefits including the formation of connective tissues, absorption of calcium, proper functioning of the thyroid gland, and sex hormones, regulation of blood sugar level, and metabolism of fats and carbohydrates. (2)

The daily intake of manganese averages 4 milligrams, with a range of 1-10 milligrams depending on the foods that are eaten. There is never any need for humans to take manganese supplements because we get more than enough of this element from food. (1)

Manganese in the Human Body

• Blood--2-8 parts per billion
• Bone--varies between 0.2 and 100 parts per million
• Tissue--varies between 0.2 and 2 ppm
• Total amount in body--about 12 milligrams

Milk is low in manganese, while liver can have as much as 10 ppm, but only a fraction of this--possibly as little as 5%--is absorbed into the body. The foods that provide most people with their supply of this element are cereal products and nuts. Beetroot has one of the highest levels of manganese (36-110 ppm dry weight). Other foods rich in manganese are sunflower seeds, coconuts, peanuts, almonds, Brazil nuts, blueberries, olives, avocados, corn, wheat, bran, rice, oats and tea. The French delicacy, snails, also contain a high level. Tree fruits such as apples and oranges, have the lowest manganese levels (1-2 ppm). (3)

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Its not just humans; manganese is an essential element for all species--indeed for some creatures, such as the red ant, it makes up 0.05% of their weight. In fact, manganese is so vital to ants that miners in the mountains of New Mexico have been reported to use anthills to plot the courses of manganese veins. (4) Some organisms, such as diatoms, mollusks and sponges, accumulate manganese. Fish can have up to 5 ppm and mammals up to 3 ppm. Manganese is an essential requirement of mice and rats, and in 1936 it was shown that the bone disease, perosis, in chickens could be prevented by giving them manganese. Manganese compounds are added to fertilizer and animals feedstuffs because this element may be lacking in certain soils, and animals grazing on such land may suffer manganese deficiency. (1) Manganese is widely distributed in nature and forms about 0.1 percent of the earth's crust. It is very commonly found in iron ores and in many other minerals, and also in coal and crude oil. Manganese is widely used in industry: manganese oxides have been used in glass manufacture since ancient times. While over 90 percent of the manganese extracted is used to make steel, it is also used in the manufacture of batteries, fertilizers, animal feed, dyes, wood preservatives, ceramics, and gasoline additives. (5)

Medical Issues

Exposure to dust or fumes from manganese is a health hazard. Workers breathing in the fumes from hot manganese suffer 'fume fever', symptoms of which are fatigue, anorexia and impotence. Miners who were affected by this condition also displayed symptoms that came to be known as 'manganese madness', exhibiting involuntary laughter or crying, aggression, delusions and hallucinations. These effects were first noted in France in 1837 and their symptoms were seen to be similar to those of another brain condition, Parkinson's disease. Fortunately, manganese madness is now rare. (1) Because manganese is so widespread in the environment, some scientists have speculated that it might be the cause of ordinary Parkinson's disease. However, it has been ultimately rejected for two reasons. First, while the clinical symptoms do include many classical parkinsonian features, victims of manganese toxicity also suffer from severe psychological disturbances (memory impairment, disorientation, anxiety, and hallucinations) as well as dystonia (an excessive increase in muscle tone or tightness that results in fixed posture of a body part). Neither of these features is prominent in early untreated Parkinson's disease. (5) Waterborne manganese has a greater bioavailability than dietary manganese. According to results from a 2010 study, higher levels of exposure to manganese in drinking water are associated with increased intellectual impairment and reduced intelligence quotients in school-age children. (6) Depressed people have high manganese levels; one theory holds that crying helps lower the levels.  Basal tears, which flow continuously, keep the eye lubricated throughout the day. Psychic tears are produced by emotional states, and have been the subject of rigorous scientific study, only to remain in large part a mystery. The chemical composition of psychic tears varies greatly from basal and reflex tears. An analysis revealed that psychic tears actually contain a greater concentration of various proteins. It also has been noted that the same tears contain thirty times the level of manganese normally found in the brains of clinically depressed patients leading scientists to speculate that the shedding of psychic tears may actually purge the brain of manganese and relieve symptoms of depressions. (7) What about manganese deficiency? Symptoms include high blood pressure, heart ailments, muscular contraction, bone malformation, high cholesterol, poor eyesight, hearing trouble, severe memory loss, shivers and tremors. Even though some medical experts argue that manganese deficiency is quite rare, more than 35% of the world population is thought to be deficient. Poor dietary habits are the leading cause of such deficiencies. (2)

Environmental Issues

Manganese has caused no know environmental damage. It is one of the most abundant metals in soils, where it occurs as oxides and hydroxides. Soil may be deficient in manganese so that animals grazing on such land may suffer, hence the need to add either manganese salts to fertilizers or manganese supplements to the animals' feedstuffs. On the other hand, in some soils manganese can approach levels that are toxic to plants, especially in acidic or poor aerated soils. Plants generally tolerate high levels in soils and this is reflected in the variable amounts they contain; grasses, for example, can have between 10 and 300 ppm (dry weight). (1)

Some Interesting Facts

• It is the 12th most abundant element on earth.
• It is the fourth most heavily consumed metal after iron, aluminum, and copper.
• The Titanic sunk as a result of too little manganese in the steel used for the ship.
• 92% of the world's high grade manganese is found in the Kalahari basin in South Africa.
• The most surprising occurrence of manganese is on the ocean floor where there is an estimated trillion tons of manganese-rich nodules scattered over large areas with the North-East Pacific being particularly rich in them. Whether these ocean nodules will ever be harvested is debatable. (1)

References

1. John Emsley, Nature's Building Blocks, (Oxford, UK, Oxford University Press, 2011), 249
2. "Health benefits of Mn," organicfacts.net, September 11, 2013
3. John Emsley and Peter Fell, Was it Something You Ate?, (Oxford, UK, Oxford University Press, 2001), 163
4. Guy Murchie, The Seven Mysteries of Life, (New York, Houghton Mifflin Company, 1999), 367
5. J. William Langston and Jon Palfreman, The Case of the Frozen Addicts, (New York, Pantheon Books, 1995), 121
6. Maryse F. Bouchard et al., "Intellectual impairment in school-age children," Environmental Health Perspectives, 119, 138, 2010
7. Michael Paul Mason, Head Cases, (New York, Farrar, Straus and Giroux, 2008), 78
8. "Manganese uses, a new mine, and the benefits of high grade ore," United Manganese of Kalahari