Recent studies have shown that a cocoa drink packed with flavanols can help safeguard the vascular system from stress, even after indulging in high-fat foods.
The foods we choose when dealing with stress can have significant effects on our cardiovascular health. Research from the University of Birmingham indicates that consuming high-fat foods can harm vascular function and oxygen supply to the brain. On the other hand, flavanol compounds found in cocoa and green tea can help maintain vascular health during everyday stress.
In a new study, the same research team discovered that drinking a flavanol-rich cocoa beverage alongside a fatty meal can help mitigate some of the adverse effects of fatty foods and protect the vascular system from stress.
This research was published today (18th November) in the journal Food and Function.
Dr. Catarina Rendeiro, an Assistant Professor in Nutritional Sciences at the University of Birmingham and the lead author, stated: “When people experience stress, they often turn to high-fat foods. Previous studies have shown that fatty meals can hinder the body’s ability to recover its vascular functions post-stress. In this study, we aimed to determine whether incorporating a high-flavanol food into a fatty meal could mitigate the negative effects of stress.”
Rosalind Baynham, the study’s first author, elaborated: “Flavanols are compounds found in various fruits, vegetables, teas, and nuts, like berries and unprocessed cocoa. They are recognized for their health benefits, especially in regulating blood pressure and supporting cardiovascular health.”
“In our study, we provided a group of young, healthy adults with breakfast comprising two butter croissants with 10 g of salted butter, 1.5 slices of cheddar cheese, and 250 ml of whole milk, along with either a high-flavanol cocoa drink or one low in flavanols. After a rest period, participants completed a challenging mental math test over eight minutes, which increased in speed, with alerts for incorrect answers. Throughout this period, we measured forearm blood flow, cardiovascular function, and oxygen levels in the prefrontal cortex (PFC). Vascular function was assessed using Brachial Flow-mediated dilation (FMD), a predictive measure for cardiovascular disease risk. This mental task induced notable increases in heart rate and blood pressure, resembling common everyday stress experiences.”
The cocoa drinks were prepared by mixing 12 g of cocoa powder with 250 ml of whole milk. The low-flavanol cocoa used was an alkalized powder, which had its flavanol content reduced to 5.6 mg per serving, while the high-flavanol cocoa was non-alkalized, providing 695.0 mg of total flavanols per serving. The alkali process, often used to enhance chocolate flavor, unfortunately diminishes flavanol content.
The research team found that consuming fatty foods with the low-flavanol cocoa drink during mental stress significantly decreased vascular function (by 1.29% FMD) and this impact lasted up to 90 minutes post-stress. Conversely, the high-flavanol cocoa drink effectively preserved vascular function following both stress and fat consumption. Brachial flow-mediated dilation readings were significantly better after the high-flavanol cocoa compared to the low-flavanol cocoa at both 30 and 90 minutes after the stress task. Additionally, their prior research indicated that high-fat foods reduced oxygen levels in the prefrontal cortex during stress, but flavanols did not improve cerebral oxygenation or affect mood.
Dr. Catarina Rendeiro emphasized: “This study demonstrates that consuming foods or drinks rich in flavanols can serve as an effective strategy to lessen the adverse effects of poor dietary choices on the vascular system. It empowers us to make more informed dietary decisions during stressful times.”
When shopping, look for minimally processed cocoa powder. If cocoa isn’t your preferred choice, other sources of flavanols include green tea, black tea, and berries. Recent guidelines suggest a daily intake of between 400 to 600 mg of flavanols, achievable through consuming two cups of black or green tea or a mix of berries, apples, and high-quality cocoa.
Jet Veldhuijzen van Zanten, a Professor of Biological Psychology at the University of Birmingham and co-author of the study, remarked: “Modern life presents numerous stressors, and the effects of stress on our health and the economy are well-documented. Any steps we can take to shield ourselves from the impacts of stress are beneficial. For those who are prone to reaching for unhealthy snacks in stressful situations or rely on convenience foods due to busy lifestyles, incorporating these small changes can lead to significant improvements.”
