COCOA, GREEN TEA: Their flavanols against STRESS

Food choices made during periods of high stress can influence and further exacerbate the effect of stress on cardiovascular health. Previous research from the same team had shown that foods high in fat can negatively affect endothelial function and oxygen supply to the brain, while flavanol compounds present in abundance in cocoa and green tea can protect the Vascular function during periods of daily stress. Several studies have also suggested that “cocoa is good for cardio”.

The study is carried out with a group of healthy young adults who received, in addition to a rich meal, a cocoa drink rich in flavonoids or low in flavonoids. After a rest period, participants were asked to complete a mental arithmetic test that increased in speed for 8 minutes, alerting them when they gave a wrong answer. Their forearm blood flow, cardiovascular activity and prefrontal cortex (PFC) tissue oxygenation were assessed during the rest period and during the test. Vascular function was also assessed based on brachial artery flow-mediated dilation (FMBD) which is a prognostic measure of future cardiovascular disease risk. The analysis reveals that:

• the test and associated stress induce significant increases in heart rate and blood pressure, similar to the stress encountered in daily life;
• the consumption of the cocoa drink – or chocolate – rich in flavanols in combination with the fatty meal counteracts part of the harmful impact of fatty foods and protects the vascular system, thus reducing in particular inflammatory and psychological stress;
• specifically, the drink rich in flavanols is effective in preventing the decline of vascular function following stress and fat consumption;
• FMBD was significantly higher after consumption of high-flavanol cocoa vs. low-flavanol cocoa, 30 and 90 minutes after the stress period.

Lead author Dr Catarina Rendeiro, Professor of Nutritional Sciences at the University of Birmingham notes that: “When people are stressed, they are even more likely to turn to high-fat foods. However, fatty foods can harm the body's vascular recovery after stress. We observe that providing a food rich in flavanols at the meal, particularly if it is fatty, alleviates the negative impact of stress on the body.”

Les flavanols are present in different fruits, vegetables, tea and nuts, including berries and unprocessed cocoa. Flavanols are known to have many health benefits, in particular, they help regulate blood pressure and protect cardiovascular health.

This research reveals that consume -reasonably- a type of food rich in flavanols, such as chocolate for exampleEast an effective strategy to mitigate part of the impact of poor dietary choices on the vascular system.