Drinking flavanol-rich cocoa can protect the body’s vasculature against stress even after eating fatty food, a study suggests.
Food choices made during periods of stress can influence the effect of stress on cardiovascular health: high-fat foods, for example, can negatively affect vascular function and oxygen delivery to the brain.
Conversely, flavanol compounds found in cocoa and green tea can protect vascular function during periods of stress – and now, UK-based researchers say that drinking cocoa high in flavanols in combination with a fatty meal can help mitigate some of the food’s effects on the body.
Lead author Dr Catarina Rendeiro, assistant professor in nutritional sciences at the University of Birmingham, said: “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.”
Flavanols, found in some fruits, vegetables, teas, and nuts, are known to have health benefits, particularly in regulating blood pressure and protecting cardiovascular health.
The randomised, double-blinded intervention study, which was published in the journal Food and Function, sought to explore whether flavanols consumed in combination with fat can mitigate the negative impact of fat on stress-induced impairments in endothelial function.
Participants ingested a high-fat meal (56.5 g fat) with either high-flavanol (150 mg of epicatechin) or low-flavanol (<6 mg of epicatechin) cocoa 1.5 hours before being asked to perform an eight-minute mental stress task. The researchers then measured their forearm blood flow, cardiovascular activity, and prefrontal cortex tissue oxygenation to assess their stress levels.
They also measured participants’ vascular function using brachial flow-mediated dilatation, a prognostic measure for future risk of cardiovascular disease.
Consuming fatty foods with the low-flavanol drink when mentally stressed reduced vascular function, with the effect lasting up to 90 minutes after the stress task was over.
However, the cocoa drink high in flavanols was effective at preventing the decline in vascular function: brachial flow-mediated dilatation was significantly higher following high-flavanol cocoa compared with low-flavanol cocoa 30 and 90 minutes after the task.
The researchers previously found that eating high-fat foods attenuated cerebral oxygenation in the pre-frontal cortex during stress.
For consumers who feel compelled to snack on fatty foods when stressed or depend on convenience meals because of work pressures or time scarcity, a shift in behaviour could result in meaningful changes, according to the study authors.
Drinking or eating flavanol-rich foods can be used as a strategy to mitigate some of the effects of poorer food choices on the vascular system, they suggested, helping people make more informed decisions about their diet when under stress.
In 2022, the US Academy of Nutrition and Dietetics published guidelines for flavanol intake, which recommend between 400 to 600 mg/day. This can be achieved by consuming two cups of black or green tea, or a combination of berries, apples, and high-quality cocoa.
Co-author Jet Veldhuijzen van Zanten, professor of biological psychology at the University of Birmingham, 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.
“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.”
Rendeiro added: “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.”
