While the concept of storing water in a copper water bottle or other copper vessel arose centuries ago and has its origins in Ayurvedic principles, the practice is gaining increasing attention from the scientific community. In fact, several recent studies have substantiated that drinking water stored in a copper vessel is a safe and beneficial health practice. In this blog post, we'll summarize the results of three recent scientific studies concerning the use of copper water vessels as well as a report from the World Health Organization.
In one recent study, which was published in the Journal of Health, Population and Nutrition, scientists studied the effect of storing water in a copper pot on microbially-contaminated drinking water, including harmful bacteria such as E.coli and salmonella. In particular, scientists stored water contaminated with this bacteria in copper pots for 16 hours at room temperature. Incredibly, following the 16-hour storage period, the scientists were unable to recover any bacteria from the water. In addition, the scientists found that the water's pH level had increased, meaning that it had naturally become more alkaline. As other studies have shown, natural alkaline water has a variety of health benefits.
Significantly, the scientists also determined that the copper content of the water was less than 0.2 ppm (parts per million), which represents an amount far less than the permissible limit set by the World Health Organization ("WHO"). As the study states, “safety of leached copper does not appear to be an issue since studies have shown that the current WHO guideline of 2 mg Cu/L is safe” and the levels absorbed in the study were well within permissible limits.
The WHO's recent report entitled Guidelines for Drinking Water Quality identified an upper limit for consumption of copper in water as 2.0 ppm (or 2 mg per litre), which is far higher than the amount of copper found in the water that was stored overnight in the copper pots as part of the study. Accordingly, the scientific evidence shows that there is no realistic risk of consuming too much copper by drinking water stored in a copper vessel, even when that water is stored in the copper vessel overnight or even for several days (more on that below). As a result, there is no realistic risk that drinking water from a copper water bottle will cause gastrointestinal irritation or other health issues.
In another recent study, scientists again studied the effect of storing water in a copper pot on water contaminated with bacteria. In this study, the scientists incubated water with a colony of harmful bacteria and then stored the water overnight at room temperature in both copper pots and glass bottles. In the morning, the bacteria was no longer recoverable from the water that had been stored in the copper pots, although it was recovered from the water stored in the glass bottles. The study found that the water stored in the copper pots had also become more alkaline.
Significantly, the scientists also determined that while the water stored in the copper pots absorbed some of the copper overnight, the water’s copper content was less than 0.475 ppm, which is well within the permissible limits for human consumption and is thus safe for drinking.
In yet another recent study, researchers stored water contaminated with bacteria in a variety of different water containers, including copper and silver containers, in order to determine their efficacy at removing biological contamination from drinking water. The study revealed that the copper vessels had a significant inhibitory effect on the bacteria in the water after only a few hours of exposure. The scientists found that the pH of the water had also increased within a healthy range.
The scientists in that study also measured the concentration of copper in the water every 2 hours in order to determine whether the water remained safe for consumption. While the scientists detected a gradual increase in the amount of copper absorbed by the water, they determined that the amount still remained well within the permissible limits laid out by the WHO even after the water was stored in the copper vessel for several days.
The following graph from the report provides a helpful illustration of the rate at which copper was absorbed into the water. In particular, the data shows that the copper levels in the water remained within permissible levels even after several days. This study suggests that storing water in a copper bottle overnight or even for a few days does not pose any risk to health.
The conclusions of these and many other research studies support what Ayurvedic medicine has been telling us for centuries: that drinking water stored in a copper vessel can be a safe and beneficial health practice. We look forward to seeing more evidence in support of the use of copper water bottles as the practice gains increased attention from scientific community.