Think You Know Everything About the Risk Factors that Increase Your Odds of Developing Heart Disease Leading to Cardiac Arrest, Stroke, and Early Death? New Study Suggests You’re Probably Wrong

Globally, cardiovascular ailments constitute a significant health challenge, as they are implicated in over 30 percent of mortalities, with an escalating incidence rate.

Cardiac disorders encompass a spectrum of conditions that may result in the constriction or occlusion of blood vessels, thereby impeding circulatory function. Furthermore, the structural integrity and performance of cardiac muscles and valves, as well as the regulation of heart rhythm, may be compromised, leading to perilous outcomes.

The etiology of heart disease is multifactorial, with genetic predisposition playing a role in some instances. However, lifestyle choices significantly contribute to the development of these conditions. For example, dietary habits lacking in nutritional adequacy, physical inactivity, and tobacco consumption are acknowledged as risk factors for cardiac ailments.

Additionally, recent findings from the American Heart Association reveal that chronic low-level exposure to lead, cadmium, and arsenic, through everyday sources such as domestic goods, air, water, soil, and food, can contribute to a heightened risk of cardiovascular disease.

This statement, published in the Journal of the American Heart Association, delves into the link between chronic low or moderate exposure to these three metals and cardiovascular ailments including coronary artery disease, stroke, and peripheral artery disease.

The study sheds light on the clinical and public health impacts of these environmental toxicants, which are currently not recognized as traditional risk factors for cardiovascular disease. Environmental cardiology is an emerging field that identifies exposure to pollutants, including these metals, as potential modifiable risks for cardiovascular disease.

As noted by Dr. Gervasio A. Lamas, the head of the panel responsible for the scientific statement and a distinguished faculty member at Mount Sinai Medical Center, large-scale epidemiological studies suggest that exposure to these metals is nearly ubiquitous and contributes significantly to the prevalence of cardiovascular diseases, notably myocardial infarctions, strokes, and peripheral vascular diseases.

These metals, as elucidated by Dr. Ana Navas-Acien, vice-chair of the panel and a renowned expert in environmental health sciences at Columbia University, “interfere with essential biological functions and affect most populations on a global scale.

“After exposure, lead and cadmium accumulate in the body and remain in bones and organs for decades. In the U.S. alone, one large study suggested that more than 450,000 deaths annually could be attributed to lead exposure.”

How does exposure to pollutant metals occur?

The ubiquitous presence of pollutant metals in our environment leads to involuntary exposure, typically via routine daily activities. Lead, for instance, is found in a myriad of materials including old house paints (the US prohibited the use of lead-based paints in 1978), tobacco-related products and second-hand smoke, tainted foods, water conduits, spices, cosmetics, electronic equipment, and industrial discharges. Both cadmium and lead can enter the body via cigarette smoking.

The sources of cadmium include nickel-cadmium batteries, colorants, plastic materials, ceramics, glassware, and construction-related items. Fertilizers produced industrially often utilize phosphate rock abundant in cadmium, thereby resulting in contamination of root vegetables and green leafy crops, tobacco included.

In the case of arsenic, the principal route of exposure is groundwater, influencing the purity of drinking water, soil, and the produce cultivated in polluted soil. It’s worth noting that arsenic tends to accumulate in rice more than in other food crops.

Although exposure and risk are prevalent among various demographic groups irrespective of socioeconomic status, certain populations may experience amplified exposure to these toxic metals. According to the statement, people living in proximity to high-traffic routes, industrial activities, and hazardous waste locations; dwelling in aged structures; or residing in areas with lax environmental regulatory enforcement and insufficient responsiveness to community grievances, are at a heightened risk.

Dr. Navas-Acien points out that this global challenge affects lower-income communities disproportionately due to their exposure to pollutant metals through contaminated air, water, and soil.

“Addressing metal exposure in these populations may provide a strategy to reduce cardiovascular disease disparities and advance environmental justice.”

What is the cardiovascular impact of pollutant metals?

The scientific statement incorporates global epidemiological studies that verify the association between lead, cadmium, and arsenic exposure, and elevated mortality rates, primarily driven by an increased risk of cardiovascular diseases. The global studies include:

• A 2021 American Heart Association scientific statement recognized toxic metal exposure as a non-traditional risk factor for peripheral artery disease.
• A comprehensive review in 2018, published in the British Medical Journal, encompassed 37 studies involving nearly 350,000 participants from over a dozen nations. The review found that heightened levels of arsenic in urine and elevated blood concentrations of lead and cadmium corresponded to an augmented risk, ranging from 15% to 85%, for cerebrovascular and cardiac diseases.
• A study conducted in China observed a correlation between increased blood lead levels and the presence of carotid plaque in individuals with Type 2 diabetes. Moreover, it found an association between cadmium and arsenic exposure and elevated incidences of cardiac diseases and ischemic stroke.
• A research study among the general population in Spain discovered a link between urinary cadmium levels and rising incidences of newly diagnosed cardiovascular diseases.

How can we mitigate environmental metallic contamination?

The advisory panel suggests regular monitoring of environmental metal concentrations and testing individuals for metal exposure as crucial measures to devise effective public health strategies. While children with symptoms suggestive of metal exposure undergo blood testing for lead levels, there are currently no monitoring guidelines or exposure limits for adults, except in specific occupational contexts. There is a need for future research to determine whether such testing could be an effective approach to identifying and safeguarding individuals at risk of cardiovascular disease.

The authors of the statement underscore that reducing metal exposure in tobacco, safeguarding community water supplies and wells, and curtailing metal pollution in air, food, and soil are all viable public health interventions that may diminish metal exposure.

Dr. Lamas, who is also a professor of medicine at Columbia University Irving Medical Center in New York City, posits that “a multi-pronged approach that recognizes environmental cardiology and includes environmental monitoring and biomonitoring of contaminant metals; controlling for sources of exposure; and developing clinical interventions that remove metals or weaken their effects on the body.”

Currently, there are no established medical treatments to counteract the vascular consequences of pollutant metals, but research is underway to explore potential therapeutic options. Some research is examining the efficacy of chelating agents, drugs that can remove pollutant metals, predominantly lead and cadmium, from the body. These agents bind to metals, facilitating their excretion.

Furthermore, the statement calls for research into nutritional supplements that might attenuate the effects of pollutant metals and expedite their excretion. Preliminary trials indicate that supplements such as folate and N-acetyl cysteine may show promise in this regard.

Source: 10.1161/JAHA.123.0298521

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