Study Finds Cocoa and tea may protect your heart from the hidden damage of sitting - Video

Sitting for long hours can silently wreak havoc on your blood vessels, but what if a simple dietary change could shield your heart? New research from the University of Birmingham shows that consuming flavanol-rich foods-such as tea, berries, apples, and cocoa-can protect men’s arteries from the vascular damage caused by prolonged sitting.

The findings were published in the Journal of Physiology.

Sitting for long hours may seem harmless but seriously harms your cardiovascular health. Research shows that prolonged sitting reduces blood flow and vessel function, leading to higher blood pressure, increased cholesterol, and insulin resistance. This creates a cascade of metabolic problems, including obesity and heightened risk of heart disease, stroke, and type 2 diabetes. Even among those who exercise regularly, sitting more than 10 hours a day sharply raises the likelihood of heart failure and cardiovascular death.

In this innovative study, 40 healthy young men with varying fitness levels participated in a two-hour sitting trial. Before sitting, they consumed either a high-flavanol cocoa drink or a low-flavanol version. Researchers measured key indicators of vascular health, including flow-mediated dilatation (FMD) in arm and leg arteries, blood pressure, blood flow, and muscle oxygenation both before and after sitting.

Results revealed striking differences: men who drank low-flavanol cocoa experienced significant declines in artery elasticity (FMD), increased diastolic blood pressure, reduced blood flow, and lower muscle oxygen levels—effects linked to higher risks of cardiovascular disease. Interestingly, these detrimental changes occurred in both fitter and less-fit individuals, indicating that physical fitness alone does not protect against sitting-induced vascular damage.

Conversely, participants consuming the high-flavanol cocoa drink maintained stable vascular function, with no significant drop in artery elasticity or muscle oxygenation. This is the first study to demonstrate that flavanols effectively prevent sitting-induced vascular dysfunction regardless of fitness levels.

The study’s lead author, Dr. Catarina Rendeiro, emphasized that incorporating high-flavanol foods and drinks during long sitting periods could help reduce cardiovascular risks associated with sedentary lifestyles. She recommends pairing such dietary habits with regular activity breaks—standing or walking—to further enhance vascular health.

REFERENCE: Alessio Daniele, Samuel J. E. Lucas, Catarina Rendeiro. Dietary flavanols preserve upper‐ and lower‐limb endothelial function during sitting in high‐ and low‐fit young healthy males. The Journal of Physiology, 2025; DOI: 10.1113/JP289038