Study reveals cocoa’s protective role in vascular health during stressful periods

New research has discovered that a cocoa drink rich in flavanols can help protect the body’s vascular system from stress, even after consuming high-fat foods.

Food choices during stressful times can influence how stress affects cardiovascular health. For instance, recent studies from the University of Birmingham found that high-fat foods can impair vascular function and reduce oxygen delivery to the brain. On the other hand, flavanols, compounds abundant in cocoa and green tea, are known to support vascular function during everyday stress, Caliber.Az reports per foreign media.

In their latest study, the same research team found that drinking cocoa high in flavanols along with a fatty meal can mitigate some of the negative effects of high-fat food and help safeguard the vascular system from stress. The research was published in the Food and Function journal. Dr. Catarina Rendeiro, Assistant Professor in Nutritional Sciences at the University of Birmingham and lead author, stated, "We know that when people are stressed, they tend to gravitate towards high-fat foods. We have previously shown that fatty food can impair the body's vascular recovery from stress. In this study, we wanted to see if adding a high-flavanol food to the fatty meal would alleviate the negative impact of stress in the body."

Rosalind Baynham, the first author of the study, explained, "Flavanols are a type of compound that occur in different fruits, vegetables, tea, and nuts, including berries and unprocessed cocoa. Flavanols are known to have health benefits, particularly for regulating blood pressure and protecting cardiovascular health." In a recent study, researchers investigated the impact of flavanol-rich cocoa on vascular function after consuming a high-fat breakfast and undergoing mental stress. Dr. Catarina Rendeiro and her team at the University of Birmingham conducted the experiment with a group of young, healthy adults, giving them a breakfast of two butter croissants with salted butter, cheddar cheese, and whole milk, followed by either a high-flavanol or low-flavanol cocoa drink. 

"We took a group of young healthy adults and gave them two butter croissants with 10 g salted butter, 1.5 slices of cheddar cheese, and 250 ml of whole milk as breakfast, and either a high-flavanol cocoa or a low-flavanol cocoa drink," Dr. Rendeiro explained. After a rest period, participants were asked to complete a challenging mental math test, which became progressively faster, with corrections given if answers were wrong. During the test and rest period, the researchers measured participants' forearm blood flow, cardiovascular activity, and oxygen levels in the prefrontal cortex (PFC). 

"We also measured vascular function using Brachial Flow-mediated dilatation (FMD), which is a prognostic measure for future risk of cardiovascular disease. This stress task induced significant increases in heart rate and blood pressure, similar to the stress you may encounter in daily life," Dr. Rendeiro added. To prepare the cocoa drinks, the researchers dissolved 12 g of cocoa powder into 250 ml of whole milk. The low-flavanol cocoa powder, an alkalized form, was processed to reduce flavanols to just 5.6 mg per serving, while the high-flavanol cocoa powder, a non-alkalized variety, contained 695.0 mg of flavanols per serving. Alkalization, a process used in chocolate making, enhances flavor but significantly reduces flavanol content. 

By Naila Huseynova