Researchers at Brock University in Ontario have recently found an interesting correlation between Alzheimer’s disease (AD) and drinking water—and no, it doesn’t have to do with the government lacing the water with mind-altering compounds. The researchers collected statistics on the levels of lithium in drinking water in 234 counties across the state of Texas. The investigators compared lithium levels naturally found in tap water with AD mortality rates, along with the incidence of obesity and diabetes, in the Texas counties.
“We found counties that had above the median level of lithium in tap water (40 mg per liter) experienced less increases in AD mortality over time, whereas counties below that median level had even higher increases in AD deaths over time,” explained lead study investigator Val Fajardo, Ph.D., a postdoctoral fellow at Brock University.
Findings from the new study were published recently in the Journal of Alzheimer's Disease in an article entitled “Examining the Relationship between Trace Lithium in Drinking Water and the Rising Rates of Age-Adjusted Alzheimer’s Disease Mortality in Texas.”
Lithium is a water-soluble alkali metal found in igneous rocks and mineral springs. While it is commonly used to treat bipolar and other mood disorders, it is administered at much higher doses than what occurs naturally in drinking water. The Brock University team focused on Texas because data on lithium levels were freely available.
“6,180 water samples from public wells since 2007 were obtained and averaged for 234 of 254 Texas counties. Changes in AD mortality rates were calculated by subtracting aggregated age-adjusted mortality rates obtained between 2000–2006 from those obtained between 2009–2015,” the authors wrote. “Using aggregated rates maximized the number of counties with reliable mortality data. Correlational analyses between average lithium concentrations and changes in AD mortality were performed while also adjusting for gender, race, education, rural living, air pollution, physical inactivity, obesity, and type 2 diabetes.”
Interestingly, the research team found that in addition to lower AD rates, the frequency of obesity and type 2 diabetes also went down when the drinking water contained similar lithium levels. Previous studies have demonstrated lithium's ability to protect against AD, obesity, and diabetes. Additionally, this study comes on the heels of data released in August from the University of Copenhagen linking high lithium levels in drinking water to decreases in dementia rates.
“However, we are one of the first groups to show that lithium's potential protective effect against AD, obesity, and diabetes may translate to the population setting through very low levels of lithium in tap water,” Dr. Fajardo remarked.
While the scientists were excited by their findings, Dr. Fajardo warned that it’s too early to start advising authorities to add lithium to drinking water. “There's so much more research we have to do before policy-makers look at the evidence and say, OK, let's start supplementing tap water with lithium just like we do in some municipalities with fluoride to prevent tooth decay,” he concluded.