Most people think of body fat as something visible, measurable on a scale or in the mirror. But some of the most influential fat in the body is hidden deep inside, quietly affecting vital organs. One example is fat around heart, a specific form of visceral fat that surrounds the heart muscle. Unlike surface fat, this type interacts directly with cardiac tissue, blood vessels, and metabolic signals. Science now shows that understanding this fat can provide valuable insight into cardiovascular risk, even in people who appear otherwise healthy.
What Is Fat Around Heart From a Medical Perspective
Epicardial and pericardial fat explained
Clinically, the fat located on the surface of the heart is known as epicardial adipose tissue. It sits between the heart muscle and the protective sac around it. Pericardial fat lies slightly farther out. Epicardial fat is especially significant because it shares blood supply with the heart itself. Research published in the Journal of the American College of Cardiology describes it as metabolically active tissue capable of releasing hormones and inflammatory molecules that influence heart function.
Why location matters more than body weight
Studies using CT and MRI imaging show that people with normal body weight can still have elevated epicardial fat. This is why cardiologists increasingly focus on fat around heart rather than relying solely on body mass index. Location determines impact, and fat stored directly next to coronary arteries behaves very differently from fat stored under the skin.
How Fat Around Heart Differs From Other Body Fat
Visceral fat versus subcutaneous fat
Subcutaneous fat mainly serves as energy storage and insulation. Visceral fat, including epicardial fat, is biologically active. It produces inflammatory cytokines and free fatty acids that influence metabolism. According to studies in Circulation, visceral fat contributes to systemic inflammation in ways subcutaneous fat does not.
Direct interaction with coronary arteries
Because epicardial fat lies directly against coronary arteries, its secretions can affect these vessels locally. This proximity helps explain why fat around heart is associated with coronary artery disease even after adjusting for cholesterol levels, waist size, and overall obesity.
Scientific Evidence Linking Fat Around Heart to Heart Disease
Coronary artery disease risk
Large population studies, including data from the Framingham Heart Study, show that higher epicardial fat volume correlates with increased plaque buildup in coronary arteries. Researchers have found this relationship remains significant even when traditional risk factors are controlled.
Inflammation and plaque vulnerability
Epicardial fat releases inflammatory mediators such as interleukin-6 and tumor necrosis factor-alpha. These substances can weaken atherosclerotic plaques, making them more prone to rupture. Reviews in Nature Reviews Cardiology emphasize that this inflammatory activity makes epicardial fat a contributor to cardiovascular events rather than a passive bystander.
Metabolic Effects of Fat Around Heart
Insulin resistance and glucose metabolism
Epicardial fat volume is closely linked to insulin resistance. Research using advanced metabolic testing shows that individuals with more epicardial fat often have impaired glucose handling, regardless of body size. This connection helps explain why fat around heart frequently appears alongside type 2 diabetes and metabolic syndrome.
Influence on blood pressure and cholesterol
Studies published in Hypertension demonstrate associations between epicardial fat and elevated blood pressure. The fat releases free fatty acids directly into nearby circulation, influencing vascular tone and lipid metabolism in ways that increase cardiovascular strain.
Fat Around Heart and Heart Rhythm Disorders
Atrial fibrillation risk
One of the most consistent findings in recent research is the link between epicardial fat and atrial fibrillation. Imaging studies show that higher levels of fat around heart increase the likelihood of developing this common arrhythmia. Inflammatory signaling appears to disrupt the electrical pathways that regulate heart rhythm.
Structural changes in cardiac tissue
Excess epicardial fat has also been associated with enlargement of the atria and subtle stiffening of heart muscle. These changes may impair the heart’s ability to relax properly, contributing to diastolic dysfunction over time.
How Doctors Detect Fat Around Heart
Imaging techniques used in practice
Cardiac CT and MRI scans are the most accurate methods for measuring epicardial fat. These tools allow clinicians to assess fat volume and thickness precisely. Such measurements are often obtained incidentally during imaging performed for other cardiac reasons.
Why it is not routinely screened
Routine screening is not currently recommended because imaging involves cost and, in the case of CT, radiation exposure. Instead, clinicians focus on managing overall cardiovascular risk factors that influence fat around heart accumulation.
Can Lifestyle Changes Reduce Fat Around Heart
Weight loss and physical activity
Randomized clinical trials show that weight loss leads to significant reductions in epicardial fat. Research published in Obesity demonstrates that aerobic exercise combined with calorie control can reduce epicardial fat thickness within a few months.
Diet quality and metabolic health
Mediterranean-style eating patterns rich in vegetables, olive oil, fish, and whole grains are associated with lower levels of epicardial fat. Improving insulin sensitivity and reducing inflammation are key mechanisms through which lifestyle changes influence this fat depot.
Who Should Pay Special Attention
High-risk groups
People with type 2 diabetes, hypertension, sleep apnea, or chronic inflammation are more likely to have increased epicardial fat. In these populations, fat around heart may contribute to elevated cardiovascular risk even when symptoms are absent.
Prevention over fear
The presence of epicardial fat is not a diagnosis or a sentence. It is a modifiable marker. Focusing on sustainable habits offers meaningful protection without unnecessary anxiety.
Conclusion
Fat around heart represents a unique and important form of visceral fat that directly influences cardiovascular and metabolic health. Scientific evidence shows it plays an active role in inflammation, coronary artery disease, insulin resistance, and heart rhythm disorders. The encouraging message is that this fat responds well to lifestyle changes supported by strong research. By prioritizing movement, nutrition, and metabolic balance, individuals can meaningfully reduce risk and support long-term heart health.
Sources
- ScienceDirect, From Cushion to Culprit: The Role of Epicardial Adipose Tissue in Cardiovascular Disease
- PubMed Central (PMC), Role of Epicardial Adipose Tissue in Cardiovascular Diseases: A Review
- Frontiers, The role of epicardial adipose tissue dysfunction in cardiovascular diseases: an overview of pathophysiology, evaluation, and managemen
- JAMA Network, Cardiovascular Significance and Genetics of Epicardial and Pericardial Adiposity
