Healthcare (Commonwealth Union) – Recent research from the University of Birmingham reveals that consuming foods high in flavanols—such as tea, cocoa, apples, and berries—can help protect men’s blood vessel health from the negative effects of extended sitting.
Prolonged sitting is a common feature of modern lifestyles, with young adults estimated to remain seated for around six hours each day. However, spending long periods inactive can lead to a decline in vascular function.
Earlier studies have found that even a 1% drop in vascular function, assessed through brachial Flow-Mediated Dilatation (FMD)—a measure of arterial flexibility—can raise the risk of cardiovascular problems like heart disease, stroke, and heart attacks by 13%.
The researchers aimed to determine whether diet—especially foods rich in flavanols—could help guard the vascular system against the harmful effects of prolonged, uninterrupted sitting.
Flavanols are naturally occurring polyphenol compounds found in foods such as fruits, tea, nuts, and cocoa beans. Previous studies have linked them to cardiovascular benefits, including protection of the vascular system during times of mental stress.
The findings were published recently in The Journal of Physiology.
Dr Catarina Rendeiro, Assistant Professor in Nutritional Sciences at the University of Birmingham, who is also the leading author, says “Whether we are sitting at desks, behind the wheel of a car, on a train, or on the sofa reading a book or watching TV, we all spend a lot of time seated. Even though we are not moving our bodies, we are still putting them under stress. 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.”
Cardiovascular-related deaths are increasing in the UK. According to the British Heart Foundation, fatalities among working-age adults rose by 18%—reaching 21,975 in 2023, compared with figures from 2019. Moreover, new research estimates that cardiovascular diseases cost the UK around £29 billion annually.
The study explored whether drinking flavanol-rich beverages before prolonged sitting could help maintain blood vessel function in the arms and legs. Forty healthy young men participated—half with higher fitness levels and half with lower fitness levels. Each consumed either a high-flavanol cocoa drink (containing 695 mg of total flavanols) or a low-flavanol version (containing 5.6 mg of total flavanols) before undergoing a two-hour sitting test.
Women were not included in this trial because fluctuations in oestrogen during the menstrual cycle are believed to influence how flavanols affect vascular health during periods of sitting. Researchers recommend that future studies investigate this effect in women.
Researchers of the study pointed out that both the lower- and higher-fitness participants who consumed the low-flavanol cocoa before sitting showed reductions in FMD in the arteries of their arms and legs. This indicates that having higher fitness levels does not protect against the vascular effects of prolonged sitting. The low-flavanol drink also led to a significant rise in diastolic blood pressure, reduced shear rate and blood flow in both arteries, and caused declines in muscle oxygenation in both fitness groups.
In contrast, participants in both fitness groups who drank the high-flavanol cocoa did not experience any FMD reductions in either the arm or leg arteries. This marks the first evidence that flavanols can prevent sitting-related vascular dysfunction in young, healthy men.
Dr Sam Lucas, Professor of Cerebrovascular, Exercise & Environmental Physiology at the University of Birmingham and co-author of the study, indicated that their experiment that increased fitness levels do not avoid the temporary impairment of vascular function brought about by sitting when just drinking low-flavanol cocoa. Dr Lucas further indicated that what is significant is following the high-flavanol drink, fitter together with the less-fit participants maintained their FMD the same as it was prior to sitting for two hours.
