Groundbreaking new research links climate change to cardiovascular health

Cardiovascular disease (CVD) stands as the leading cause of death globally, responsible for approximately one-third of all deaths. In 2021 alone, over 20 million people lost their lives to heart-related conditions, according to a 2024 report from the World Heart Federation.

While advances in heart disease prevention and treatment have significantly reduced CVD deaths in recent years, the ongoing threat of climate change poses a new and formidable challenge. The steady rise in global temperatures, fueled by relentless fossil fuel combustion, threatens to reverse these hard-won gains.

NASA has documented a rise in the average global temperature by more than two degrees Fahrenheit over the past century. This warming has driven long-term shifts in weather patterns, disrupted ecosystems, and caused sea levels to rise. Alarmingly, the past decade has recorded the ten hottest years in history. This trend is more than just a climate concern; it directly impacts human health, particularly heart health.

A new study conducted by researchers at Beth Israel Deaconess Medical Center (BIDMC) sheds light on the connection between climate change and cardiovascular disease. By reviewing 492 observational studies, the researchers explored how climate-related environmental stressors impact heart health.

Their findings, published in JAMA Cardiology, highlight that extreme temperatures and severe weather events like hurricanes significantly increase both CVD mortality and the incidence of heart diseases. Particularly vulnerable to these effects are older adults, racial and ethnic minorities, and those in lower-income communities.

“Climate change is already affecting our cardiovascular health,” stated Dhruv S. Kazi, associate director of the Richard A. and Susan F. Smith Center for Outcomes Research at BIDMC.

Related Stories

He explained, “Exposure to extreme heat can adversely affect heart rate and blood pressure; ozone or wildfire smoke can trigger systemic inflammation; living through a natural disaster can cause psychological distress; and hurricanes and floods can disrupt healthcare delivery through power outages and supply chain interruptions. Long-term, the changing climate is expected to decrease agricultural productivity and the nutritional quality of our food supply, further compromising cardiovascular health.”

Kazi emphasized the urgent need to understand the full extent of these impacts and identify which populations are most at risk.

In their extensive review, Kazi and his team screened nearly 21,000 studies published from 1970 to 2023, focusing on acute cardiovascular events, CVD mortality, and healthcare utilization linked to climate change-related phenomena. These included extreme temperatures, wildfires, air pollution, and various severe weather events like hurricanes and droughts. The 492 studies that met their criteria spanned high-income countries, middle-income countries, and only one from a low-income country.

Their analysis revealed stark findings: extreme temperatures significantly increased the risk of cardiovascular disease and mortality. The effects varied based on the severity and duration of the temperature extremes. Severe weather events, such as hurricanes and floods, were also linked to heightened cardiovascular risk, with impacts lasting long after the events themselves.

For instance, a study on Hurricane Sandy, which caused nearly $20 billion in damages in New York City in 2012, found that the risk of death from cardiovascular disease remained elevated for up to a year post-storm. Similarly, exposure to wildfire smoke, which can affect areas far from the source, was associated with increased risks of cardiac events, though findings varied across studies.

Kazi pointed out the need for more research, especially given the increasing exposure to wildfire smoke in recent years. “With so many Americans experiencing wildfire smoke annually, like the smoke from Canadian fires affecting New York City last summer, it is crucial to conduct further studies to accurately quantify this risk,” he said.

A significant concern raised by the study is the lack of data on how climate change impacts cardiovascular risk in low-income countries. Out of all the reviewed studies, only one was conducted in a low-income nation, and just five were based in Africa, despite the expectation that these regions will suffer disproportionately from climate change.

Mary B. Rice, MD, MPH, a senior author of the study and a physician in the division of Pulmonary and Critical Care Sleep Medicine at BIDMC, highlighted the gaps in knowledge. “Our study shows that environmental stressors linked to climate change are increasing cardiovascular risk. However, data on low-income countries are critically lacking,” she noted.

The findings suggest that healthcare providers should consider how climate change exposures contribute to each patient’s cardiovascular risk. This means assessing individual, community, and systemic vulnerabilities. For example, in hurricane-prone areas, clinicians should help patients develop plans to maintain access to necessary medications and healthcare during and after such events. Healthcare systems also need to evaluate their infrastructure's resilience to climate impacts.

Kazi stressed the immediate need for action: “Climate change is already adversely affecting cardiovascular health in the U.S. and worldwide. Urgent measures are needed to mitigate climate change-related cardiovascular risks, especially for our most vulnerable populations.”

As the planet continues to warm, the intersection of climate change and cardiovascular health becomes an increasingly critical issue. Addressing this challenge will require not only robust scientific research but also comprehensive public health strategies and policies to protect the most at-risk populations from the dual threats of climate change and heart disease.

Note: Materials provided above by The Brighter Side of News. Content may be edited for style and length.

Like these kind of feel good stories? Get the Brighter Side of News' newsletter.