Sipping on green tea or cocoa might just be your best defence against the detrimental effects of stress and fatty foods, a new study by the University of Birmingham suggests. The research indicates that a drink rich in flavanols can protect one’s body even after consuming high-fat meals, with choices made during stressful periods potentially altering how stress affects cardiovascular health.
It follows previous findings by the team that high-fat diets can hinder vascular function and oxygen delivery to the brain. However, compounds in green tea and cocoa known for their flavanol content were seen to shield vascular function under stress.
Now, they’ve determined that coupling cocoa abundant in flavanols with a fatty meal can mitigate some negative effects of such foods, thus safeguarding the vascular system amidst stress.
Dr Catarina Rendeiro, who is an Assistant Professor in Nutritional Sciences, commented on the discovery: “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 study’s lead author and a research fellow, has highlighted the potential health benefits of flavanols, stating: “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.”
She detailed an experiment involving young adults who were given a breakfast followed by either a high-flavanol or low-flavanol cocoa drink and then subjected to a mental maths test: “During the eight-minute rest period and eight-minute mental maths test, we measured forearm blood flow, cardiovascular activity and prefrontal cortex (PFC) tissue oxygenation. 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.”
The cocoa beverages were concocted by mixing 12g of cocoa powder with 250ml of whole milk. One variant used low-flavanol cocoa powder which had been alkalized, reducing its flavanol content to a mere 5.6mg per serving, while the other was created using high-flavanol, non-alkalized cocoa powder, boasting 695mg of total flavanols per serving, reports Surrey Live.
The study results, which found their way into the pages of the journal Food and Function, indicate that pairing high-fat meals with the low-flavanol cocoa drink amid mental stress led to a reduction in vascular function by 1.29% FMD, an effect lingering long after the stressful incident, up to 90 minutes. Conversely, the high-flavanol cocoa drink was hailed as an “effective” countermeasure against stress and fatty food-induced decline in vascular health, with a “significantly higher” brachial flow-mediated dilatation noted post-consumption at both 30 and 90-minute marks following stress.
Dr Rendeiro said: “This research shows that drinking or eating a food high in flavanols can be used as a strategy to mitigate some of the impact of poorer food choices on the vascular system. This can help us make more informed decisions about what we eat and drink during stressful periods.”
She highlighted that for those keen on keeping their health in check, it’s best to opt for a minimally processed cocoa powder while shopping. Additionally, green tea, black tea, and berries are also potent sources of flavanols. According to the latest guidelines, a daily intake of 400 to 600 mg of flavanols is recommended, achievable by consuming two cups of black or green tea, or a mix of berries, apples, and high-quality cocoa.
Professor Jet Veldhuijzen van Zanten, who co-authored the study, said: “Modern life is stressful and the impact of stress on our health and the economy has been well documented, so any changes we can make to protect ourselves from some of the symptoms of stress is positive.”
She added: “For those who tend to reach for a treat when stressed or depend on convenient food because they work high-pressure jobs or are time-poor, incorporating some of these small changes could make a real difference.”