Can Fat You Can't See Put You at Risk for Stroke and Heart Attack? - Video

A new study published in Communications Medicine reveals that fat stored deep within the abdomen and liver, often invisible on the surface, can silently damage arteries, increasing the risk of heart attacks and strokes even in people who appear outwardly healthy.

The research focuses on visceral fat, which surrounds internal organs, and hepatic fat, which accumulates in the liver. Both have previously been associated with chronic conditions like Type 2 diabetes and high blood pressure, but their direct effect on artery health was less understood. Using advanced MRI imaging and data from more than 33,000 adults in Canada and the United Kingdom, the researchers found a strong link between these hidden fats and the thickening and clogging of the carotid arteries, major blood vessels that supply the brain.

“This study shows that even after accounting for traditional cardiovascular risk factors like cholesterol and blood pressure, visceral and liver fat still contribute to artery damage,” said Russell de Souza, co-lead author and associate professor at McMaster University.

The team analyzed data from two large population cohorts—the Canadian Alliance for Healthy Hearts and Minds (CAHHM) and the UK Biobank. They used MRI scans to assess fat distribution and carotid artery health. The findings revealed that visceral fat was consistently associated with plaque buildup and arterial thickening, while liver fat had a weaker but still significant impact. Crucially, these associations remained even after adjusting for metabolic and lifestyle factors.

The implications are significant. For doctors, it suggests that BMI and waist size are not enough; advanced imaging may be necessary to detect cardiovascular risks in seemingly healthy individuals. For middle-aged adults, it serves as a reminder that what’s happening inside the body matters more than what’s visible on the outside.

Reference: de Souza, R.J., Pigeyre, M.E., Schulze, K.M. et al. Visceral adipose tissue and hepatic fat as determinants of carotid atherosclerosis. Commun Med 5, 424 (2025). https://doi.org/10.1038/s43856-025-01123-y