Does sitting all day harm your heart? A new study reveals how flavanols in foods like cocoa and berries can protect your blood vessels. Discover how to stay healthy.
A new study from the University of Birmingham suggests that consuming foods rich in flavanols, such as tea, berries, apples, and cocoa, could help protect the heart and blood vessels from the damage caused by sitting for extended periods.
In modern life, sitting has become a common activity. Young adults typically spend around six hours each day sitting, whether at a desk, in a car, on public transport, or while relaxing at home. However, sitting for long periods can weaken blood vessel function. Even a small decline in blood vessel performance is associated with a greater risk of serious heart issues, including heart disease, strokes, and heart attacks.
This research aimed to determine if eating foods high in flavanols might help counteract these negative effects.
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What Are Flavanols?
Flavanols are natural substances found in many fruits, nuts, tea, and cocoa beans. They have been linked to benefits for heart health, such as aiding blood vessels under stress. Earlier studies suggested that flavanols may help protect the cardiovascular system, and this new research supports that finding.
Heart disease remains a significant health issue. In the UK, deaths among working-age adults rose by 18% to 21,975 in 2023 compared to 2019. Cardiovascular conditions cost the country about £29 billion annually.
Can Flavanols Help Protect Blood Vessels While Sitting?
The researchers tested if flavanols could help maintain healthy blood vessels during a two-hour sitting session. Forty healthy young men participated. They were divided equally between those with higher and lower fitness levels. Each participant drank either a high-flavanol cocoa drink (695 mg of flavanols per serving) or a low-flavanol cocoa drink (5.6 mg per serving) before sitting.
Women were not included in this study because hormonal changes during the menstrual cycle can affect how flavanols work. However, the researchers hope to include women in future studies.
Before and after the sitting session, the team measured several indicators of blood vessel health, including:
• Blood vessel function in the arm and leg arteries (known as Flow-Mediated Dilatation or FMD)
• Blood flow and shear rate (how blood moves through the arteries)
• Blood pressure
• Oxygen levels in the leg muscles
High-Flavanol Cocoa Helps Maintain Blood Vessel Health
Men who drank the low-flavanol cocoa experienced a drop in blood vessel function, higher blood pressure, slower blood flow, and lower oxygen levels in their leg muscles, despite being physically fit. This shows that being fit alone does not fully protect against the effects of sitting for long periods.
In contrast, men who drank the high-flavanol cocoa did not experience these declines. Their blood vessels stayed healthy throughout the two-hour sitting period, regardless of their fitness level. This is the first study to show that flavanols can prevent the negative effects of sitting on blood vessel function in healthy young men.
Dr Sam Lucas, Professor of Cerebrovascular, Exercise, and Environmental Physiology and a co-author of the study, said: “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. Importantly, after the high-flavanol drink, both fitter and less-fit participants kept their FMD the same as it was before sitting for two hours.”
The study also found that a person’s initial fitness level does not affect how flavanols influence blood vessels. This suggests that flavanol-rich foods may support heart health for everyone, not just those who are physically active.
How to Include Flavanols in Your Daily Life
Alessio Daniele, a PhD student at the University of Birmingham, said it’s easy to add flavanol-rich foods to your diet. Many cocoa products found in supermarkets and health stores are processed to keep flavanol levels high. Other options include fruits like apples, plums, and berries, as well as nuts and black or green tea.
So, while we can’t always avoid sitting, small changes to your diet, along with simple movement breaks, could go a long way in keeping your heart healthy.
