Of late there appears to be a spurt in usage of copper containers, flasks and tumblers for storing and consumption of water. This is due to perceived health benefits. Such waves are not uncommon in India. This is also related to a fad that we should relive our ancient wisdom, Ayurveda in the present case.
If one googles for “health benefits of copper vessel”, one gets umpteen number of web sites which laud the beneficial effects. Terms such as Copperized water and copper infused water which are not supported in chemistry are found in such articles. The claimed benefits are wide ranging. Anti-aging, promoting weight reduction, anti-oxidant, preventing cancer etc. Of al the perceived benefits the one concerning weight reduction is interesting. It is not clear whether the effect is unconditional or conditional. It is also supposed to balance three Doshas (kafa, vaata and pitta) present in the body, which incidentally the very foundation of the Ayurvedic system of medicine. None of them is based on any study and hence is neither authentic nor reliable. A typical web page can be browsed at thehealthsite.com
COPPER AND WATER
According to chemistry copper does not react with water. Copper may react with the dissolved oxygen and form cupric or cuprous oxide. These oxides form a dull layer on the surface. It is known that copper attains a bright shiny surface just after cleaning. But when exposed to moist atmosphere the shine disappears and we observe oxide coating resulting in dull surface. The oxides can dissolve in ater.From this consideration stainless steel is superior.
Copper, however, is superior to stainless steel in one respect. It has pronounced Oligodynamic effect along with silver and brass. The Oligodynamic effect is defined (source: Wikipedia) as "a toxic effect of metal ions on living cells, algae, moulds, spores, fungi, viruses, prokaryotic and eukaryotic microorganisms, even in relatively low concentrations”. Water stored in such containers gets relieved of bacteria after several hours.
COPPER AND HEALTH
Copper is an essential trace element present in the human body. The amount present is about 2 milligrams per kilogram of body mass. This means that an average male has less than 0.2 grams of copper present in the body. Copper deficiency is very rare and hence people need not bother about copper at all. Though supplements are available they need to be taken only in exceptional cases that too under proper medical supervision. Copper presence in excess can be detrimental and can even cause neurological disorders. We get copper from greens, nuts, dark chocolate, certain types of seafood, livers of animals etc.
Words of caution from some of the proponents
Copper is not innately utilized by our body. That is why too much of the metal can be detrimental. According to the FDA, about 12 mg/day is more than sufficient for the body to use without causing any harm. So, do not overdo the entire exercise. Drinking water twice or thrice in a day from a copper vessel is more than enough to reap its benefits.
Do not overdo it, drinking water stored in a copper bottle twice a day (morning and evening) is more than enough to provide the necessary amount of copper to your body.
Take breaks from drinking water stored in a copper bottle. For example, take a month long break after regularly drinking water stored in a copper bottle for two months. This allows the body to flush out the extra copper.
Copper containers are to be used solely for water at room temperature.
Some of the main disadvantages of drinking water in a copper vessel for a long period are digestive discomfort, vomiting, and nausea. While drinking water from a copper vessel, you should ensure that the pitcher or vessel you use is clean. Do not scrub the inside of the bottle or use detergent to clean the vessel. Rub the vessel with lemon and wash with water.
To Sum up
Let us take copper and stainless steel for comparison. But for Oligodynamic effect one can say that stainless steel is superior. For drinking and cooking we generally use treated water which is generally free from bacteria. So the benefit due to Oligodynamic effect is marginal. On the flip side copper jugs and tumblers need to be treated with special care to ward off the detrimental effects of oxidation. Stainless steel is totally free from any such chemical changes. Also copper is recommended by proponents for only storing cold water. Stainless steel containers, on the other hand, are all-purpose utensils. Many of the proponents are also warning against over usage.
Thus drinking water stored in copper vessels is at best equivalent to drinking water from stainless steel containers. However one needs to exercise certain caution in respect of copper which are not warranted in the case of stainless steel.