Most of us spend long hours sitting: at a computer at work, driving, on the train, in class, or in the evening in front of the TV. Even though sitting feels like “rest,” our bodies, especially our blood vessels, pay a price for it. A new study from the University of Birmingham in England shows that the damage begins after just two hours without movement, and that even people in excellent shape are not protected.
But the truly surprising part is the solution the researchers suggest. Drinking a cocoa beverage rich in certain natural compounds, or eating foods such as tea and apples, can almost completely prevent the drop in blood flow. To understand why, it helps to know what happens in the body during prolonged sitting.
When we sit, blood flows more slowly in the legs, and the arteries respond by losing some of their ability to widen properly. This decline is measured by an index called FMD, or flow mediated dilation. Previous studies have shown that even a small drop of just 1% in this measure raises the risk of heart disease, stroke and heart attacks by 13%. In simple terms, even if you are young and healthy, prolonged sitting harms blood vessels in a way that cannot be ignored.
Even top athletes were not able to escape the damage
That is where flavanols come in. Despite a name that sounds like something found only in a lab, these are natural substances present in tea, berries, apples, nuts and, of course, cocoa. For years they have been known to support heart health and help blood vessels handle stress, including mental stress. The researchers wanted to see whether these substances could also protect the body during long periods of sitting, and it turns out they can, very clearly.
The study included 40 young, healthy men. Half had high physical fitness and half had lower fitness. Before a continuous two-hour sitting session, each participant drank one of two beverages: a cocoa drink very rich in flavanols, or a low-flavanol cocoa drink, meaning regular cocoa you would find in stores. The study has not yet been expanded to women because hormonal changes could affect the results, but the researchers say this is planned for future studies.
During the experiment, several measures were taken: the ability of blood vessels to widen (FMD), blood flow in the legs and arms, shear rate, which reflects the impact of flow on arteries, blood pressure and oxygenation levels in leg muscles. The results were sharp and consistent. Men who drank the low-flavanol beverage showed a significant decline in blood vessel function. Fitness did not protect them, even the most athletic participants were affected. They also showed an increase in diastolic blood pressure and a drop in muscle oxygenation.
By contrast, those who drank the flavanol-rich beverage showed no decline in blood vessel function, neither in the arms nor the legs. In effect, their bodies behaved as if they had not sat at all. This is the first study to clearly show that simple natural compounds found in cocoa can almost entirely neutralize the harm of prolonged sitting.
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It kept participants’ blood vessels working as if they had not sat at all: cocoa
(Photo: Shutterstock)
“Even people with high fitness are affected by sitting, but after a flavanol-rich drink their blood vessels stayed exactly as they were before the sitting,” said Prof. Sam Lucas, one of the study leaders. “That is a meaningful difference.”
One of the study’s more surprising findings was that fitness level did not change the body’s response to flavanol intake at all. In other words, even people who run, swim or train regularly are still harmed by long sitting, and can still benefit from drinks rich in these natural compounds. That makes the recommendation relevant to nearly everyone.
What can you do at home?
The researchers stress that there is no need to start drinking a special lab-made cocoa beverage. Plenty of everyday foods are easy to add: high-quality cocoa sold in health stores, black and green tea, apples, plums, berries and nuts. The idea is to supply the body with those natural substances that help keep blood vessels open and active even while we sit for hours.
Dr. Catarina Rendeiro summed it up simply: “If we are already sitting a lot, it is worth giving the body something that helps it cope. A cup of tea, a high-quality cocoa drink, or fruits rich in flavanols are an easy way to reduce the damage from sitting. And if you add a short break to stand up, stretch your legs or take a few steps, that is even better.”