High cadmium exposure from smoking may be linked to an increased risk of thinking and memory issues, according to a study reported in Neurology. The investigation followed about 2,000 adults with an average age around 64 who did not have cognitive problems at baseline. Urinary cadmium was measured at the start, and participants completed annual reasoning and memory tests over a mean follow-up of roughly ten years.
Over the study period, 195 participants developed cognitive impairment. When the data were examined for the entire group, there was no overall association between cadmium levels and cognitive decline. However, analyses stratified by race revealed a different pattern: white participants with higher cadmium levels exhibited about double the risk of developing cognitive impairment compared with whites with lower cadmium exposure. Across the entire cohort, 9.2 percent of those with high cadmium developed thinking or memory problems, compared with 6.7 percent of those with lower cadmium exposure.
The researchers adjusted for several known risk factors for cognitive impairment, including a sedentary lifestyle, alcohol consumption, and education level. These adjustments aimed to isolate the potential contribution of cadmium exposure to cognitive outcomes while recognizing the influence of lifestyle and socioeconomic factors.
One proposed explanation for the racial difference observed might involve smoking patterns. The study found that among participants with the highest cadmium levels, white individuals had a smoking index roughly twice that of white individuals with the lowest exposure, and highercadmium levels did not align in the same way across different racial groups. This finding suggests that smoking-related cadmium exposure could interact with other health or environmental factors to influence cognitive trajectories in later life. Further research is needed to understand these relationships and to determine whether specific public health strategies could mitigate risk in high-exposure populations.
In broader terms, these results highlight the ongoing importance of reducing smoking and monitoring environmental toxins as part of strategies to support cognitive health in older adults. While findings point to potential differences by race in how cadmium exposure relates to cognition, they underscore the general principle that modifiable behaviors and exposures can play a role in brain aging. Ongoing investigations will help clarify which individuals are most at risk and how best to intervene to preserve memory and reasoning abilities over time.
Because the study relied on urine cadmium measurements and annual cognitive testing over a long period, it reflects a careful approach to observing real-world exposure and its possible cognitive consequences. Clinicians and public health professionals may use such data to counsel patients about the risks of smoking and environmental cadmium exposure, particularly for older adults who may already face a heightened vulnerability to cognitive changes.