Lead by the Heart

Tobacco smoke, diabetes, obesity, dyslipidemia. What do they have in common? For one, they are all well-known risk factors of cardiovascular disease (CVD) – the world’s biggest killer. Now, The American Heart Association has released a statement confirming a close link between CVD and metal exposure – a factor that is hard to regulate and harder to avoid. 

“Work by us and others has found that contaminant metals – in particular lead, cadmium, and arsenic – are associated with increased risk of CVD across populations globally,” says Ana Navas-Acien, Professor at the Department of Environmental Health Sciences, Columbia University. The metals have been associated with a wide range of heart-related health issues, including coronary artery stenosis, left ventricular hypertrophy, and peripheral artery disease. And although the FDA seeks to regulate the amount of lead leaching into our environment, exposure still occurs in contaminated groundwater, industrial fertilizer, paint, and some foods.

The paper focused on the clinical and public health implications of such exposure, and how particular sociodemographic factors increase CVD risk. In the US, communities of lower socioeconomic status and communities of color are more affected by metal contaminants in the air and water. Why? Risk of exposure is greater for those living near industrial plants or in places where environmental complaints are not adequately addressed. “This is a source of environmental injustice,” exclaims Navas-Acien. 

To approach this disparity, the study recommends rigorous government and public health intervention. “Urgent protocols are needed to protect community water systems from lead contamination and private well users from arsenic exposure,” suggests Navas-Acien. Further regulations include new medical treatments that eliminate metals or counteract their toxic effects on the heart. The study reviewed a past clinical trial – one that assessed chelation therapy – and were surprised to discover that metal chelation helped prevent CVD and diabetes. The information proved diabetes to be a disorder that impairs metal metabolism, which can be fixed by removing contaminant metals.

Though further research is needed to characterize the effect of metals on the cardiovascular system, Navas-Acien concludes: “This is an exciting time in the field of cardiology. This new sub-discipline focused on environmental strategies will contribute to further prevention and intervention strategies and mitigate current inequalities in the burden of cardiovascular disease.”