Lithium is a naturally occurring element found in groundwater. When you drink tap water, you consume small amounts of lithium, depending on its concentration in your geographic area.

Environmental studies have shown a link between higher lithium levels in drinking water and lower rates of suicide and crime. Scientists suggest this may be due to lithium’s mood-stabilizing effects. Another potential benefit that has been explored is cancer protection.

A study published in JAMA Network Open by Luo et al. examined the relationship between cancer risk and lithium levels in drinking water. Researchers analyzed health records from 252,178 Americans and compared them with estimated lithium exposure based on ZIP codes across different regions of the United States.

The analysis showed that eastern states generally had lower estimated lithium exposure, while western states had higher levels.

Estimated Lithium Exposure From Drinking Groundwater. Eastern states had a lower estimated lithium exposure compared with western states.

The study evaluated the risk of several types of cancer, including:

• Breast cancer (female)

• Prostate cancer (male)

• Bladder and urinary cancers

• Central nervous system cancers

• Colorectal cancer

• Kidney cancer

• Leukemia

• Non-Hodgkin lymphoma

• Thyroid cancer

The key finding was consistent: people living in areas with higher lithium levels in drinking water had lower rates of cancer. This pattern was observed across men and women, different regions of the U.S., and individuals who had lived in the same location for many years.

Most of the apparent benefit occurred as lithium levels increased from very low to moderate. At higher levels, the additional benefit was smaller.

Regions in the western United States, where lithium levels tend to be higher, also showed lower cancer rates. However, the study has important limitations. The authors note that the observed effect may not be caused by lithium itself. Other factors, such as sunlight exposure or regional lifestyle differences, could also play a role.

Researchers have proposed possible biological mechanisms. Lithium is known to interact with enzymes such as GSK-3β and inositol monophosphatase, both of which are involved in pathways linked to cancer development.

There is also indirect evidence from clinical observations: some patients taking lithium for psychiatric conditions have been reported to have lower cancer rates.

Nonlinear Association Between Estimated Lithium Exposure From Drinking Groundwater and Risk of All Cancers. Most of the apparent benefit occurred as lithium levels increased from very low to moderate, with smaller additional effects at higher levels.

Overall, the findings suggest an association between lithium exposure in drinking water and reduced cancer risk. However, this does not prove causation, and further research is needed to clarify whether lithium itself plays a direct protective role.

Science Sources:

• Cancer Risk and Estimated Lithium Exposure in Drinking Groundwater in the US

• Inhibitory phosphorylation of glycogen synthase kinase-3 (GSK-3) in response to lithium: evidence for autoregulation of GSK-3

• Glycogen Synthase Kinase 3β in Cancer Biology and Treatment

• Emerging role of inositol monophosphatase in cancer

Read Next:

• Lithium Ascorbate: A New Look at an Old Element

• Healthy People Benefit from Taking Lithium

• American Doctors Often Don’t Follow Lithium Treatment Guidelines