WEDNESDAY, Feb. 18, 2026 (HealthDay News) -- Cumulative lead exposure is suggested as a potential dementia risk factor, according to a study published online Feb. 12 in Alzheimer's & Dementia.
Xin Wang, Ph.D., M.P.H., from the University of Michigan in Ann Arbor, and colleagues examined prospective associations between lead exposure and incident Alzheimer disease (AD) and all-cause dementia. Blood lead was measured at baseline and patella and tibia lead were estimated for 6,217 and 5,865 participants, respectively, from the National Health and Nutrition Examination Survey (NHANES)-III (1988 to 1994) and 8,038 and 4,824 participants, respectively, from continuous NHANES (1999 to 2016), and was then linked to Medicare and the National Death Index for incident AD and all-cause dementia.
In continuous NHANES, the researchers found that when comparing quartile 4 with quartile 1, estimated patella lead was associated with AD and all-cause dementia (hazard ratios, 2.96 and 2.15, respectively). Weaker associations were observed in NHANES-III. No association was seen for blood lead.
"Once lead enters the body, it can remain stored in the bones for decades," Wang said in a statement. "As individuals age, lead may be released from the bones and migrate to organs such as the brain. This underscores the importance of assessing cumulative lead exposure when studying long-latency brain diseases, including dementia."