University of Birmingham researchers found a simple dietary move that could protect your heart—even when you’re stuck sitting all day. The secret? Flavanols, natural compounds found in cocoa, berries, apples, tea, and nuts.
Why it matters
Just two hours of uninterrupted sitting can harm blood vessel function, raising your risk of heart disease, stroke, and heart attack. Consuming flavanol-rich foods, however, can help block this damage before it occurs, regardless of your fitness level.
The problem
Young adults spend about six hours a day sitting. Prolonged sitting reduces flow-mediated dilation (FMD), a key measure of artery health. A 1% drop in FMD equals a 13% higher risk of cardiovascular disease.
The study
Forty healthy young men—half highly fit, half less fit—drank either a high-flavanol cocoa drink (695 mg flavanols) or a low-flavanol version (5.6 mg). Then they sat still for two hours.
A closer look
Those who drank the low-flavanol drink saw FMD drop in both arm and leg arteries. Their diastolic blood pressure rose, blood flow slowed, and leg muscle oxygenation fell. Fitness offered no protection.
The big picture
What about the high-flavanol group? No decline in FMD. Zero. Their arteries stayed as healthy after two hours of sitting as they were before.
This is the first study to show flavanols can fully prevent sitting-induced vascular dysfunction.
What to know
- Flavanols work whether you’re super fit or not.
- Baseline cardiorespiratory fitness didn’t change the outcome.
- Everyone benefited equally from the high-flavanol drink.
The backstory
Flavanols are plant-based polyphenols known to support vascular health during mental stress. This study tested them against the physical stress of stillness—and they delivered.
Reality check: The trial only included men. Hormonal fluctuations in women (like those during the menstrual cycle) may affect how flavanols work, so future studies will explore this gap.
How it works
Flavanols appear to maintain healthy blood flow and arterial elasticity during inactivity. They're a dietary shield when movement isn’t an option.
The takeaway
Adding flavanol-rich foods can help offset the hidden harms of sitting.
- Cocoa
- Apples
- Plums
- Berries
- Nuts
- Black or green tea
The bottom line
Look, we can't always avoid sitting—but we can fight back. Add a quick walk and some flavanol-packed foods to your day, and you're basically giving your heart a secret shield.
