Aluminum (Al)

Al – Aluminum is found in igneous rocks at 5,000 ppm, shales at 82,000 ppm, sandstone at 25,000ppm, limestone at 4,200ppm and clay at 71,000 ppm. Aluminum represents 12% of the Earth’s crust (most common metal in the Earth’s crust) and is found in high concentrations in all plants grown in the soil including food crops. Acid soils yield highest amounts of soil aluminum to plants. It is found in marine plants at 60 ppm and is especially high in plankton and red algae; land plants at (0-5 to 4,000 ppm) an average of 500 ppm; marine mammals at 19 to 50 ppm and is found in the highest levels in the hair and lungs. Known biological function is to activate the enzyme succinic dehydrogenase, increases survival rate of newborn and according to Professor Gerhardt Schrauzer, head of the department of chemistry at UCSD, is probably an essential mineral for human nutrition.

Aluminum does not appear as a free metal in nature, but is found only in tight combination with oxygen forming a hard oxide known as alumina. When contaminated with traces of other elements alumina becomes a gem such as rubies or sapphires (used in Ayruvedic medicine).

Sir Humphrey Davy, a prominent English chemist of the 16th century named the metal of clay “aluminum”.

The Danish physicist, Hans Christian Oerstad (1825) “discovered” electromagnetics and first isolated aluminum by treating alumina containing clay with carbon, chlorine amalgam of potassium to get a mixture of volatile mercury and aluminum; he boiled the mercury away as a vapor which left a powdery metal that “in color and luster somewhat resembles tin.”

Kaolin, another fine particle clay used medicinally to control diarrhea (kaopectate) is a clay with a high alumina content (35 %!). Alunite and anorthosite are aluminum containing rocks that are found in Wyoming, Utah and other western states. Laterite, a low yield bauxite has been discovered in large quantities in Oregon, Washington and Hawaii. Metallic aluminum is also found in oil shale and fly ash from coal furnaces (the metallic aluminum from these industrial pollutants contaminate our air, water and food supply).

Aluminum makes up 12 % of Earth’s crust and is therefore the Earth’s most abundant metallic element. Aluminum is found in large biological quantities in every plant grown in soil, animal and human. You can’t eat any grain, vegetable, fruit or nut or drink any natural water source or juice without taking in large quantities of aluminum!

The aluminum found in plants is organically bound colloidal aluminum and appears not to have any negative affect and in fact appears to be an essential element in human nutrition.

Many studies have linked chronic exposure to metallic aluminum to Alzheimer’s Disease, a relatively new disease that results in a loss of reasoning, memory and speech. Alzheimer’s Disease strikes 4 million Americans annually and is the fourth leading cause of death in adults after cancer, heart disease and stroke.

In a study that appeared November 5, 1992 in the science journal, Nature, Frank Watt, et al (University of Oxford) used a highly accurate laboratory technique to quantify the levels of aluminum in the brains of Alzheimer’s patients. To their great surprise, they found the same levels of aluminum in the brains of the non-Alzheimer’s controls as they did in their Alzheimer’s patients! Watts believes that aluminum contaminated stains gave faulty results in the early studies that high lighted aluminum. A 1994 study “implicated” zinc as a causative factor in the genesis of Alzheimer’s disease.

A July 1992 study released by UCSD stated that vitamin E would relieve memory loss in Alzheimer’s patients – this result is not too surprising in light of the history of it star-gazing” in poultry, where encephalomalacia or brain wasting (Alzheimer’s Disease) was prevented and in the early stages cured by high doses of vitamin E and selenium.

A study reported in the Medical Journal of Australia, that it was a fact that drinks in aluminum cans contained more aluminum than water from the local water supply. In 106 aluminum cans and bottles representing 52 different beverages, all had higher aluminum content than the local water supply which was 1.8 umol/L. Non cola soft drinks averaged 33.4 umol/L from cans and 5.6 umol/L from bottles cola drinks averaged 24.0 umol/L from aluminum cans and 8.9 umol/L from bottles; beer in cans and bottles averaged 6.0 umol/ L thus adding another source of metallic aluminum to the human food chain.

A. Distribution and Sources

Aluminum is the third most abundant element in the earth’s crust, exceeded only by oxygen and silicon. However, it is found only in trace amounts in biological organisms. Because of its reactive nature, Al occurs in combination with oxygen, silicon, fluoride (F), and other elements and compounds. In many of its compounds Al is insoluble, and its concentrations are quite low in most surface and ground freshwater supplies (Miller et al., 1984).

B. Metabolism

Aluminum is abundant in the environment; however, despite this consistent exposure, little Al is absorbed or retained. Rats and mice presented with a moderately high dietary Al content (160 to 335 ppm) simply excreted most of it in the feces. A larger dose fed to rats overwhelmed their resistance to absorption and resulted in increased urinary, as well as fecal, excretion (Ondreicka et al., 1966). The gastrointestinal absorption in children was less than 1% for different Al salts (Wilhelm et al., 1990). Retained Al in rats, mice, and dogs is deposited in the liver, skeleton, brain, and probably other tissues (NRC, 1980). The kidneys are the major pathway for the elimination of any absorbed or systemically administered Al (Alfrey, 1986).

C. Aluminum as an Essential Element

There is no conclusive evidence that Al has any essential function in animals, but indirect evidence suggests it may (Sorenson et al., 1974). Aluminum accumulates in regenerating bone, stimulates certain enzyme systems involved with succinate metabolism, and is reported essential for fertility in female rats (NRC, 1980). Aluminum increased the growth rate of poults, but this may have resulted from prevention of the absorption of high levels of F (Struwe and Sullivan, 1975). For goats, Anke et al., (1990) found low-Al diets did not affect feed consumption and growth, but life expectancy was reduced.

D. Natural Sources of Aluminum in Food and Water

Most foods and beverages contain low concentrations of aluminum naturally. The exceptions are herbs and tea leaves, which often contain more than 100 mcg aluminum per gram. However, the real contributions of these products to the aluminum intakes of humans are small for two reasons. Most adults consume only small amounts (Averages can be misleading because the aluminum content of plant materials, especially “aluminum accumulators” such as tea, can vary greatly because of differences in plant varieties and soil conditions including pH. For example, Eden observed that although tealeaves often contain approximately 1,000 mcg Al/g; some have been found to contain 17,000 mcg Al/g.

Aluminum is naturally present in surface and groundwaters. Aluminum-containing flocculants that are used to clarify municipal water supplies might be assumed to add significant amounts of aluminum to finished waters. However, the Safe Drinking Water Committee of the National Academy of Science doubted this assumption. Miller et al. found that the concentrations of aluminum in finished water at 186 water utilities in the United States ranged from A typical adult in North America or Europe would probably consume 2-10 mg of aluminum daily from natural sources.

E. Food Additives as a Source of Aluminum

Food additives are generally the major dietary source of aluminum in the United States. In 1982 approximately 4.0 million pounds of aluminum was used in food additives in the United States. This means that the average U.S. citizen theoretically consumed 21.5 mg aluminum daily in food additives. Usage of food disappearance data in this manner tends to overestimate intake somewhat.

The intake of aluminum from food additives varies greatly among individuals because although aluminum-containing food additives are widely used, only a few foods contain significant quantities of these additives. The Committee on the GRAS List Survey-Phase III estimated that 5% of adult Americans consume more than 95 mg aluminum daily in food additives. In 1982, the most commonly used aluminum-containing food additives were bentonite, sodium aluminum phosphate-acidic, sodium aluminum silicate, sodium aluminum phosphate-basic, aluminum lakes of various food dyes and colors, and aluminum sulfate. Baked goods prepared with Chemical leavening agents and certain processed cheeses were the foods that contributed the greatest amounts of aluminum in food additives to the diets of Americans in 1982.

F. Packaging and Utensils as a Source of Aluminum

Several researchers have suggested that aluminum cooking utensils were a major source of aluminum in food. Generally, investigators have found that most foods stored or cooked in aluminum pans, trays, or foil accumulated some aluminum. However, most foods have been found to accumulate less than 2 mcg Al/g of food during preparation and storage.

Several factors appear to influence the accumulation of aluminum by foods cooked in aluminum pans, i.e., pH, length of cooking period, and usage of new pans or pressure cookers. Thus tomato sauces cooked for several hours in aluminum pans accumulated 3-6 mg of aluminum/100 g serving. In foods, citric acid, not just acid in general, may also lead to increased solubilization of aluminum. Tennakone and Wickramanayake also reported that the presence of fluoride in the cooking water would increase the accumulation of aluminum in foods cooked in aluminum pans.

G. Pharmaceutical Sources of Aluminum

The quantities of aluminum consumed in food and beverages are small compared to the amounts of aluminum that can be ingested in pharmaceutical products, such as antacids, buffered analgesics, antidiarrheals, and certain antiulcer drugs. Lione estimated that 840-5,000 mg aluminum and 126-728 mg aluminum were possible daily doses of aluminum in antacids and in buffered analgesics, respectively.