Pages

Thursday, September 23, 2010

2.12e The Minor Metals in Nutrition and Toxicity

Physician's Notebooks 2  - http://physiciansnotebook.blogspot.com - See Homepage
                                                   Update 06 December 2017
2.12e: Continues Chapter - Minor Minerals
Aluminum, Arsenic, Boron, Bromine, Cadmium, Cobalt, Fluorine, Germanium, Lead, Lithium, Manganese, Mercury, Molybdenum, Nickel, Rubidium, Thallium, Tin, Silicon and Vanadium

Aluminum (Al) is a silvery white metal known for its pots. Its 3 loose outer electrons give the ion Al3+. Animal experiment showed decreased life expectancy from Al-free diet suggesting trace amount may be essential but most interest is long-term toxicity from eating out of aluminum pot. Dementia, seen in patients on kidney dialysis where exchange fluid is high in aluminum, suggests chronic aluminum in body increases risk of Alzheimer's Disease. My advice is to avoid habitual daily intake of canned food and drink and don’t use aluminum cookware for eating & drinking. Many antacids are loaded with Al. (But not Tums)  Relieve your paranoia by blood test for serum Aluminum. Less than 10μg/mL is normal. With 10-20, repeat once a year, strictly limit Al intake. More than 20 needs consultation.

Arsenic (As) name derives from zarnik, Iranian for ‘the golden’ color of arsenic trisulfide. Arsenic is a gray brittle semi-metal and reacts as 3+ and 5+ ions. Because its compounds were easy to obtain and it is toxic, it reigned as king of poison (especially of kings) used by the Borgias. But scientists recognized increasingly the therapeutic property of arsenic topped by Paul Ehrlich’s discovery of Salvarsan (arsphenamine), the first chemotherapeutic against syphilis that worked
Arsenic is in drinking water and seafood. Low-grade toxicity is seen where it is high in well water, and lifetime drinking leads to cancer of skin and pre-cancerous unsightly lesion. Bangladesh is infamous for it. Mrs Clare Booth Luce, Ambassador to Italy in 1950's, was a famous case of arsenic poisoning from paint chips falling into her breakfasts in bed from the stucco roses that decorated her bedroom ceiling. She died at age 84 of brain tumor.
   Surprisingly, arsenic deficiency has been induced in animals and its signs are depressed growth and infertility as well as heart muscle weakness. No cases reported in human but a study correlated decreased serum arsenic with increased cancer, vascular disease and stroke, suggesting a trace requirement in nutrition.

Boron (B) with 3 unstable electrons in outer orbital is in Periodic Table Group 13 with aluminum; it forms the ion B3+, and is a lightweight brownish semi-metal that occurs mainly as a salt of boric acid B(OH)3. “Boron” comes from its natural occurrence as borax (sodium borate, Na2B4O7), whose white powder gave the Persian “burah” that became “boron”.
   In the 1870's, borax and boric acid (BA) were food preservatives. Now, BA is banned as preservative and used mainly as hot healing soak. As early as 1923, small amount of boron (as borate salt) was shown to be essential for plant growth. In 1981, came 1st evidence of Boron required for animal growth.
   Boron in body is borate salts of Na+ and K+. In body fluid it is weak acid. Function of boron in body is unclear. Data show it is essential nutrient and interesting point is that in blood it is kept in narrow range, suggesting being conserved because essential. In China the boron in soil is high, resulting in blood boron range of 450-659 ng/mL, compared to normal blood level of 20-67 ng/mL with no report of toxicity at higher blood level. Boron may be a useful dietary factor. In experiment on men over the age 45 and postmenopausal women, the subjects were first fed a diet free of boron for 63 days and then, while continuing the diet, took 3 mg boron supplement a day for 49 days. Tests of nervous system before and after boron suggest improved psychomotor skill, mental alertness (less drowsiness), and better memory and attention from the boron.
   Food sources of boron are non-citrus fruit, leafy vegetable, nut and legume.

Bromine (Br) is a burning red liquid with choking odor in the Periodic Table Group 17 of fluorine, chlorine, iodine. Its bromide (Br-) salts are high in sea-water and -foods. It is strong single-electron attractor (Oxidizing agent) to fill vacancy in outer electron shell. Bromides were an early tranquilizer and still exists as “Bromo-Seltzer” and in our language as “bromide” (tranquilizing cliché).
   Dietary deficiency of Br- in goat causes depressed growth, low fertility, anemia and reduced life expectancy. Deficiency is seen in kidney hemodialysis patient where low serum Br- has been connected with insomnia. Grain, nut and fish provide rich source. Human requirement for bromine, if any, must be tiny.

Cadmium (Cd) is soft white metal used in battery for recharge and in nuclear reactor because it acts like treacle to absorb neutrons and slows down or stops reactions. Cadmium may be nutrient in ultra-trace amounts; its interest to us is toxicity. It has long half-life in body and damages several organs, but mostly kidney. It is part of ecology pollution because of heavy use in and our use of batteries. It gets into food chain from grain grown in high Cd soil and shellfish from Cd polluted sea. It is also a risk for painters, especially artists because its compounds form pretty-looking tints. It should be included in blood test for toxic metals because rising blood serum level is early warning.

Cobalt (Co); its main interest nutritionally is being the central atom of vitamin B12. Its serious toxicity has been reported as Jamaican beer syndrome, from drinking too much beer stored in cobalt alloyed iron cans. Co has no dietary requirement.

Fluorine (F) is in the halogen group (with the elements Cl, I, Br) lacking one electron to complete outer orbital. It has strong attraction for electron to form F, the fluoride ion. It is poison gas in F2 molecular state. The name is from fluorspar, a light green mineral that fluoresces in UV light and is calcium fluoride, CaF2As hydrofluoric acid (HF) it is destructive. It first attracted nutritional attention as ionic fluoride (F) salt whose high concentration in well water in the U.S. west caused discoloration of teeth called Colorado brown stain. Eating 2 mg or more fluoride a day in food or water causes the staining. More than 10 mg a day for seven years leads to crippling skeletal arthritis and bone pain. Investigation showed a little less than 2 mg a day fluoride reduces incidence of tooth cavity without causing the staining. (In 2011, controversy flared about the safety but 50 years of public fluoridation suggests the worry is unfounded) Since 1945 communities are fluoridating drinking water and now 52% of the U.S. The fluoridation also decreases osteoporosis. Best food source of fluoride is tea and sea fish. At present the only reason to take fluoride supplement is to reduce cavities in communities without fluoridation. It may have protective effect against osteoporosis. I am in favor of fluoridation but do not advise fluoride pills. 
Germanium (Ge) is a brittle gray white semi metal used in transistor; it is in health-food store because its compound has inhibited tumor formation in animal test. Low intake was shown to alter mineral composition and decrease bone DNA in rat, interpreted as evidence of essential nutrient deficiency. Among some who ate high-dose supplement, a toxic kidney effect is reported.

Lead (Plumbum, Pb): Used in storage battery, formerly as house paint and in water pipe (plumbing). Today, toxicity comes from leaded gasoline; also it can leach from old pipes into tap water (cf. the 2015 Flint Michigan U.S.A. Pb contamination from the effect of the polluted Flint River on tap-water pipes leading to blood Pb levels >100 micrograms per deciliter) and from ceramic eating bowls. Most recently the cases are coming from ingestion of Ayurvedic herbal remedies. Surprisingly, recent research shows that in pig and rat, Pb may be an essential nutrient in tiny amount. In human, the worry is toxicity, especially in inner city kid eating old wall paint. Lead poisoning shows paralysis from wrist with drooping hand and inability to raise it as in waving bye-bye. Low IQ and behavioral problems are reported in children with blood lead level as low as 10 to 15 micrograms per deciliter (μg/dL). In adults, peripheral neuropathy, convulsions and brain herniation are worst effects. In blood test, higher than 25μg/dL is sign of toxicity. Blood lead of 10 to 25μg/dL should be worrisome and sign of chronic lead poisoning. It is estimated that million American kids exceed this. An advised protective measure is to allow water tap to run for 30+ seconds before drinking, because initial flow has highest lead content. Its tap water toxicity is an argument for home water activated charcoal filter.

Lithium (Li) is soft white, lightest alkali metal; best known as lithium carbonate in treatment of manic (bipolar) depression; its one electron in outer orbital makes electron donor and gives the Li+ ion. In goat and rat, a deficiency has been shown and is guessed in human. Its salt, acting as tranquilizer may explain why violent crime is more frequent in low-lithium drinking water areas. Therapeutic daily dose for lithium is 350 mg and highest intake recorded for un-medicated person due to high level of lithium in drinking water is 8 mg a day.
   “Normal” serum lithium in blood sample is 4.8 to 109 ng/gm wet weight whole blood. (The wide range is due to variation in Li in water source) Important for accurate lithium test is that blood sample has calcium or heparin anticoagulant because other anticoagulant may be contaminated with lithium and will give false high value.
It seems worthwhile, if you are disturbed by manic personality trait, to get blood lithium test. A test <3 ng/gm suggests lithium deficiency and therapeutic trial with lithium supplementation supervised by expert. Food rich in lithium is egg, processed meat, fish, milk and its products, potato and vegetable, but the amount is much dependent on lithium content in soil and water in area where crop is grown or food-source animal raised.

Manganese, Mn: Name derives from its magnetic ore; it is hard, brittle gray-white metal, it forms Mn2+ and Mn3+. It has been known as essential in trace since the 1930's. Forms part of various enzymes, mostly in mitochondria, the submicroscopic organelles important in extracting energy from oxidation reactions. Deficiency has been induced in various species. In human, experimental Mn deficiency is said to cause defect in the synthesis of vitamin K, which could lead to excessive bleeding. Manganese deficiency is associated with osteoporosis, epilepsy, diabetes and atherosclerosis. Taken by mouth, its compounds are relatively nontoxic. In miners, fume containing manganese leads to manganic madness, a hallucinatory psychosis; chronic exposure has caused Parkinson-like disease.
Mercury (Hg hydrargyrum, Latin, quicksilver)  has 2 electrons in outermost orbital; its reactivity is Hg+ (mercurous or mercury I) or Hg++ (mercuric or mercury II). It occurs in nature as HgS, the main ingredient of the painter’s cinnabar, and, in modern times via industrial pollution, mostly as the methyl mercury pollutants. Either way you get it by mouth and as far as known it has no nutritional value but can cause toxic illness mostly to the brain. Seafood is the main source of toxicity. Low-mercury fish (Good) are shrimp, canned light tuna (opposed to “white tuna,” read on can label), salmon, pollack and catfish. The white tuna is the most dangerous because of the habitual eating of tuna salads and sandwiches. Among light tuna products, a can using water is lower mercury than with oil. The symptoms of low-level mercury toxicity are controversial but it may harm learning in children and worsen dementia like Alzheimer's. The blood mercury ought to be less than 10 microgram per liter serum. Persons having 10 to 20 micros, should strictly avoid all but low-mercury fish; above 20 micros seek chelation treatment from a metabolic MD specialist. The Mad Hatter in Alice in Wonderland is example of chronic mercury poisoning that used to afflict British hatters because of use of mercury in cleaning the hats. In our time Minamata disease is infamous in Japan from contaminated sea fish.

Molybdenum, Mo: Hard silvery white metal used in steel alloy; it forms Mo6+ and Mo2- ions. In body and in food it mainly exists as part of molybdate (MoO42-) salt. Mo has tiny nutritional need making it ultra-trace mineral. It functions as part of some enzymes, and its deficiency has been noted in a few cases of chronically ill patients being fed purely by IV fluid. The deficiency syndrome is mainly chemical with low blood uric acid (good if you worry about gout) and low blood sulfate levels. (All these patients had severe chronic illness so it is hard to connect symptom with deficiency state) A rare, deadly genetic inborn error of metabolism "sulfite oxidase deficiency", may be improved by treating the newborn infants with molybdenum.

Nickel, (Ni) is a hard metal element resembling iron and attracted by magnet. The 5-cent USA coin is partly made of it. Its ions are Ni2+ and Ni3+. It plays part in forming metal-enzymes. Function and deficiency has not been found but evidence is enough to say it has essential status in trace in human diet. It is involved in vitamin B12 and folic acid so one might expect deficiency anemia. Except for huge overdose, toxicity is limited to Ni allergy from rings on fingers, causing itchy eczema rash. Symptom of poisoning occurs with oral dose Ni salt 250 mg. Food sources of Ni include chocolate, nut, dried bean, pea and grain. Given the low need, deficiency must be rare.

Rubidium (Rb) is soft silvery white alkali metal in group of Na and K. Deficiency syndrome has been shown in goat.

Silicon, Si: Brown semi-conducting non-metal. Tiny Si chip is at heart of every computer. With 4 electrons in outer orbital, it resembles carbon in its chemical reactions. Planetologists speculate on an ET form of life based on silicon rather than carbon as we are. Early as 1911, research suggested small amount of Si in diet had anti-atherosclerosis action but no proof. As recently as 1972 it was considered nonessential to diet. Intestinal absorption of Si in usual inorganic form (glass, sand) is nil so, if you worry about Si poisoning from glass, re---lax. Silicon is absorbed well from seafood such as mussel and is measurable in urine, suggesting we are subject to it in diet. Its importance is in connective tissue – cartilage and tendon; incorporated into bone.
   Silicon deficiency has not been defined for human. In animal experiment with artificial low Si diet, bone and cartilage abnormalities abound. Most interest today is potential relationship of Si to Alzheimer's disease. Rats fed diet low in calcium and silicon and high in aluminum accumulate higher aluminum in brain than rats fed same diet but without the silicon. Using such animal as control, silicon supplementation prevents it. Is Si supplement preventive of Alzheimer’s?  And if one wishes to try, what safe dose?  Experimental questions that still need answering.

Thallium (Tl) has no nutritional value and is only mentioned because it is touted in health food store as supplement. It is poisonous in almost any dose. Avoid it.

Tin (Sn, Latin stannum, “ingot”, from ductile bars of tin in Ancient Rome): It is silvery white metal, from ancient times, a close cousin of lead Pb and exactly above it in the Periodic Table. Like lead Pb, its advantage is its low melting point and ability to form useful alloy, of which, bronze (with copper), gave name to a historical period. Unlike lead, it is nontoxic. Because tin is not chemically reactive with acid foods its use in tin-can gives it interest. (Cf. the Tin Man of The Wizard of Oz) Dietary deficiency has been demonstrated in rat but, surprisingly, considering the long history of eating out of tin can, reports of chronic tin toxicity are rare. It has no known nutritional value.

Vanadium (Va) for goddess Vanadis, or Freya (Of Friday fame) is gray, high-melting soft metal in steel. It reacts in 4+ or 5+ electron donating state and in body as VO2+, vanadyl ion. No nutritional or toxic significance. Some consider it a healthy longevity ion, in low dose. My doctor's office in Tokyo offers special Va water in its waiting room office cooler. I drank it once and I'm still standin.
   End of Chapter. For next now, click 2.13a The Water of Our Body - Internal Milieu



No comments: