UMass Chan Medical School in Worcester will use a $4.1 million grant from the National Institutes of Health to investigate whether exposure to metals like cadmium, zinc and manganese plays a role in cognitive decline and Alzheimer’s disease risk. The project, announced October 28, will draw on blood samples and health records from more than 3,000 participants in the long-running Framingham Heart Study.
The research is led by Honghuang Lin, a professor of medicine and co-director of UMass Chan’s Program in Digital Medicine, according to UMass Chan. As reported by This Week in Worcester, the National Institutes of Health provided the funding, and Lin and his colleagues will measure 18 metals total, including cadmium and zinc, while examining associations between metal levels and signs of cognitive decline, including changes in brain structure.
Tracking Decades of Health Data
The study leans on one of medicine’s most enduring research resources. The Framingham Heart Study began in 1948, when it initially recruited 5,209 men and women ages 30 to 62 from the town of Framingham, and it has since enrolled the children and grandchildren of those original volunteers, per This Week in Worcester. The National Heart, Lung and Blood Institute describes the study’s history and procedures, noting that participants return for exams and lab tests every two to six years.
Because some participants have been followed for more than seven decades, the UMass Chan team can test whether metal levels measured earlier in life are associated with brain health later on, the university’s announcement states. Lin’s team will track which participants go on to develop Alzheimer’s disease or a related dementia, and the project builds on Lin’s prior use of Framingham data in dementia research, including a 2025 UMass Chan study that used regularly updated cognitive measures to predict Alzheimer’s risk.
Why Metals Are Under Scrutiny
Metals occupy a complicated place in brain science. Some are essential for normal brain function, while others affect the nervous system, and Lin said that metal exposure and how the body processes it may interact with genetics and other biological factors to influence cognitive aging and Alzheimer’s risk, according to the university’s announcement. Lin said the findings could ultimately help guide efforts to protect brain health and reduce the burden of Alzheimer’s disease.
Outside research offers some early, though unresolved, clues about what such a study might find. A 2026 study found that cumulative exposure to metal mixtures was associated with detrimental effects on cognitive function in older adults, according to a report published in BMC Geriatrics. That research, which followed 349 older adults in 2021 and 2024 and measured cumulative metal exposure through blood samples, found cognitive decline significantly linked to the metal mixtures, including attention deficits associated with copper and lead and altered amyloid markers tied to lead.
Animal Research and Competing Findings
Separate research out of the University of Washington found that low-dose cadmium exposure accelerated cognitive impairment in mice, particularly those carrying the APOE E4 gene variant linked to Alzheimer’s risk, per the University of Washington School of Public Health. In that study, cadmium impaired short-term spatial working memory in all of the tested animals, with deficits appearing as early as three weeks after exposure.
Iron has drawn its own, somewhat conflicting attention. A 2026 NIH Alzheimer’s disease and related dementias research progress report described a study in which higher brain iron levels, particularly in the entorhinal cortex, predicted both the onset of mild cognitive impairment and faster cognitive decline over time. Separately, a study listed on PubMed described excessive iron load and accumulation in older age as potentially capable of triggering neuroinflammation and cognitive decline, while a review published in PMC pointed to arsenic, manganese, lead and cadmium as critical environmental risk factors for the development and progression of Alzheimer’s disease. None of these findings have been confirmed within the UMass Chan project itself, which has not yet produced results.
A Growing Local and National Concern
The stakes for Massachusetts are considerable. The Alzheimer’s Association has reported that more than 135,000 Massachusetts residents have Alzheimer’s disease, and the organization estimated that 7.4 million Americans ages 65 and older were living with the condition in 2026. Without medical breakthroughs, the Alzheimer’s Association has projected that number could reach 13.8 million nationwide by 2060, a trajectory UMass Chan’s own announcement echoed in describing a disease that could affect nearly 14 million Americans by that year.
For now, the UMass Chan project remains in its early stages, with no results yet available on whether metal exposure actually drives the cognitive changes researchers are watching for. The scale of the Framingham Heart Study’s decades-long records gives Lin’s team an unusually long runway to look for answers, even as the broader scientific record on metals and brain health remains mixed.
