Research from the University of Birmingham indicates that regularly consuming foods high in flavanols, such as cocoa and tea, can help mitigate the detrimental effects of prolonged sitting on cardiovascular health. The study, published on November 25, 2025, highlights the potential of flavanol-rich foods to preserve vascular function, even among physically fit individuals.
With sedentary behavior becoming increasingly common, young adults reportedly spend around six hours a day sitting. This prolonged inactivity has been linked to significant declines in blood vessel function. Past studies show that even a mere 1% decrease in vascular function, assessed through a method known as brachial flow-mediated dilation (FMD), can elevate the risk of serious cardiovascular conditions, including heart disease and strokes, by approximately 13%.
The research aimed to investigate whether specific dietary interventions, particularly those focused on flavanol intake, could counteract the vascular deterioration associated with extended periods of sitting.
Understanding Flavanols and Their Impact
Flavanols are natural polyphenolic compounds found in various fruits, nuts, tea, and cocoa beans. Previous studies have established their cardiovascular benefits, including the enhancement of vascular health during periods of psychological stress.
Dr. Catarina Rendeiro, Assistant Professor in Nutritional Sciences at the University of Birmingham and the lead author of the study, emphasized the importance of addressing the health risks linked to sedentary lifestyles. She noted, “Finding ways to mitigate the impact that sitting for uninterrupted periods has on our vascular system could help us cut the risk of developing cardiovascular diseases.”
The British Heart Foundation reported a concerning rise in cardiovascular-related deaths among working-aged adults in the UK, with figures increasing by 18% to 21,975 in 2023 compared to 2019. This underscores the urgent need for effective dietary strategies to improve vascular health.
Examining the Effects of Flavanols During Prolonged Sitting
To explore the protective potential of flavanols, the researchers conducted a study involving forty healthy young men, evenly split between those with higher and lower fitness levels. Participants consumed either a high-flavanol cocoa drink, containing 695 mg of flavanols, or a low-flavanol counterpart with just 5.6 mg, prior to a two-hour sitting session. Women were excluded from the study due to potential hormonal variations affecting vascular responses.
Before and after the sitting period, researchers evaluated various indicators of vascular health, including FMD, blood pressure, and muscle oxygenation levels. The findings revealed that participants consuming the low-flavanol drink experienced notable declines in FMD and increases in diastolic blood pressure.
In contrast, those who consumed the high-flavanol cocoa maintained stable FMD levels, demonstrating that flavanols can effectively prevent the vascular dysfunction induced by prolonged sitting. Dr. Sam Lucas, Professor of Cerebrovascular, Exercise & Environmental Physiology at the University of Birmingham and co-author of the study, stated, “Our experiment indicates that higher fitness levels do not prevent the temporary impairment of vascular function induced by sitting when only drinking low-flavanol cocoa.”
The results also indicate that flavanol intake positively impacts vascular health irrespective of an individual’s fitness level, suggesting a broader applicability of flavanol-rich foods for promoting cardiovascular wellness.
Incorporating Flavanol-Rich Foods into Daily Life
A key takeaway from the research is the ease of integrating high-flavanol foods into everyday diets. Alessio Daniele, a PhD student at the University of Birmingham, pointed out that products rich in flavanols, such as certain cocoa items and fruits like apples and berries, are widely available in supermarkets and health stores.
Dr. Rendeiro added, “Given how common sedentary lifestyles have become, using flavanol-rich food and drink, especially in combination with breaking up periods of inactivity by going for a short walk or standing up, could be a good way to enhance long-term health, no matter the individual’s fitness level.”
As the prevalence of cardiovascular diseases continues to rise, this research underscores the potential of simple dietary changes to improve vascular health and combat the adverse effects of a sedentary lifestyle.
