Bulletin Board
Archived Bulletin Board
About John
Latest Ideas
Symptoms
Tests and Drugs
Weight Loss Experiment
Hyperthyroidism
Hypothyroidism
Supplement List
Medical Science
Heredity
Other Diseases
Thyroid Physiology
Deeper Studies
Nutrients and Toxics
Hair Analysis
Book Reports
Glossary
Table of Contents | |
GERMANIUM
- Rough file:
-
Regul Toxicol Pharmacol 1997
Jun;25(3):211-9 |
|
Hazard assessment of germanium supplements.
Tao SH, Bolger PM
Center for Food Safety and Applied Nutrition, Food and Drug
Administration, Washington, DC 20204, USA.
Germanium-containing dietary supplements became popular in the 1970s in
Japan and later in other countries, as elixirs for certain diseases
(e.g., cancer and AIDS). Germanium is not an essential element. Its
acute toxicity is low. However, at least 31 reported human cases linked
prolonged intake of germanium products with renal failure and even
death. Signs of kidney dysfunction, kidney tubular degeneration, and
germanium accumulation were observed. Other adverse effects were anemia,
muscle weakness, and peripheral neuropathy. Recovery of renal function
is slow and incomplete even long after germanium intake was stopped. The
total dose of ingested germanium (as dioxide, carboxyethyl germanium
sesquioxide, germanium-lactate-citrate, or unspecified forms) varied
from 15 to over 300 g; the exposure duration varied from 2 to 36 months.
In laboratory animals, elevated germanium in tissues and impaired kidney
and liver function were observed in a life-time drinking water (5 ppm
germanium) study. Other toxicities associated with ingested germanium
products in human cases were also demonstrated in animal studies with
germanium dioxide and sometimes other germanium compounds. Based on the
evidence of persistent renal toxicity associated with germanium dioxide,
the lack of conclusive findings of differential nephrotoxicity of
organic germanium compounds, and the possibility of contamination of the
organic germanium products with inorganic germanium, it is clear that
germanium products present a potential human health hazard.
Title
- Nephrotoxicity and neurotoxicity in humans from organogermanium compounds
and germanium dioxide.
- Author
- Schauss AG
- Address
- Life Sciences Division, American Institute for Biosocial Research, Inc.,
Tacoma, WA 98401.
- Source
- Biol Trace Elem Res, 29(3):267-80 1991 Jun
- Abstract
- There is no known biological requirement for germanium (Ge),
germanates, or any organogermanium compound. Ge deficiency has not been
demonstrated in any animal. The estimated average dietary intake of Ge in
humans is 1.5 mg/d. Ge is widely distributed in edible foods, all of which,
with few exceptions, contain less than 5 ppm Ge, since higher levels are
toxic to most plants. Ingestion of Ge compounds has been shown to produce
toxic effects in experimental animals. In recent years inorganic germanium
salts and novel organogermanium compounds, such as carboxyethyl germanium
sesquioxide (Ge-132) and lactate-citrate-germanate (Ge lactate citrate) have
been sold as "nutritional supplements in some countries for their
purported immunomodulatory effects or as health-producing elixirs, resulting
in intakes of Ge significantly exceeding the estimated average dietary
intake. Since 1982, there have been 18 reported cases of acute renal
dysfunction or failure, including two deaths, linked to oral intake of Ge
elixirs containing germanium dioxide (GeO2) or Ge-132. In
these cases, biopsies show vacuolar degeneration in renal tubular epithelial
cells, without proteinuria or hematuria, in the absence of glomerular
changes. Serum creatinine levels have been well above 400 mumol/L in such
patients. In 17 of 18 cases, accumulated elemental Ge intakes reportedly
ranged between 16 to 328 g over a 4-36 mo period, or between 100 to 2000
times the average estimated dietary intake for human. In surviving patients,
renal function improved after discontinuation of Ge supplementation.
However, in no case was recovery complete. One organogermanium compound, an
azaspiran organogermanium compound, 2-aza-8-germanspiro[4,5]
decane-2-propamine-8,8-diethyl-N,N-dimethyl dichloride (spirogermanium), has
been found to cause both neurotoxicity and pulmonary toxicity in phase I and
II studies examining its chemotherapeutic potential as an antitumor drug in
the treatment of various malignancies. In cancer patients given the drug
spirogermanium, 40% experienced marked, yet transient neurotoxicity. Two
patients suffered from pulmonary toxicity. Results of phases I and II human
cancer trials for spirogermanium have not been favorable, with the exception
of moderate benefits for three types of malignancies. It is recommended that
patients exposed to long-term (greater than 3 mo) Ge supplementation at
levels well above the estimated daily intake be medically supervised and
monitored for potential renal-, pulmonary- or neurotoxicity. Further study
regarding the mechanism of Ge-induced nephrotoxicity in human is warranted.
|