Environmental metals like arsenic, copper, cadmium and mercury could be contributing factors to cardiovascular disease—even at low levels of exposure and in developed countries, Cambridge researchers reported in the BMJ Aug. 29.
Toxic heavy metals have been a point of concern for environmentalists for years, first author Rajiv Chowdhury, PhD, and colleagues at the University of Cambridge said in the journal, but those worries centered mostly around the metals’ carcinogenic properties. However, as toxic chemicals continue to make their way through the world’s water supplies and irrigation systems and leak into our food supply, growing research suggests they could have consequences beyond cancer.
“Whether a detrimental association with cardiovascular disease exists in low or medium levels of exposure remains unclear,” Chowdhury, an associate professor in global health at Cambridge’s School of Clinical Medicine, and co-authors wrote. “Therefore, given the global nature of the toxic metal contamination, accurate characterization of the associations between these environmental contaminants and cardiovascular disease is essential to understand to etiology of cardiovascular disease, and, critically, to inform public health efforts to reduce toxic metal exposure.”
Chowdhury et al. conducted a large-scale review of published studies on the subject, gathering data from 350,000 unique participants across 37 countries. They found those with the highest exposure to arsenic, lead, cadmium and copper were between 30 percent and 80 percent more likely to develop CVD than the lowest-exposure group. Mercury wasn’t associated with an increased risk of heart disease.
“It’s clear from our analysis that there’s a possible link between exposure to heavy metals or metalloids and risk of conditions such as heart disease, even at low doses—and the greater the exposure, the greater the risk,” Chowdhury said in a release from Cambridge. “While people shouldn’t be overly worried about any immediate health risk, it should send a message to policymakers that we need to take action to reduce people’s exposure.”
The authors said exposure to these elements disproportionately affects people in low- and middle-income countries, but that doesn’t mean places like the U.S. or U.K. are spared. Exposure is still a threat to people's’ health, even if it’s at a lower level.
They said smaller steps like using environmentally friendly water filters at home and rinsing rice and vegetables before cooking could go a long way.
“These findings reinforce the often under-recognized importance of environmental toxic metals in cardiovascular risk, beyond the roles of conventional behavioral risk factors,” Chowdhury and colleagues wrote. “Further detailed work, however, to better characterize these associations and to assess causality, is needed.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.