Chocolate Counteracts the Effects of Sleep Deprivation

SOURCE: Grassi D, Socci V, Tempesta D, et al. Flavanol-rich chocolate acutely improves arterial function and working memory performance counteracting the effects of sleep deprivation in healthy individuals. J Hypertens 2016;34:1298-1308.

Sleep deprivation has become a major health issue in the United States, with more than 50-70 million adults suffering from sleep disorders. It has been found that sleep deprivation can be detrimental for cardiovascular health and cognitive function. Sleep alters the autonomic nervous system; therefore, disorders interrupt the normal regulation of blood pressure (increasing BP) and can lead to increased inflammation, endothelial dysfunction, and increase oxidative stress. Taking it one step further, high BP has been linked to Alzheimer’s disease, cognitive impairment, and vascular dementia.

There has been great interest in finding a product that can ameliorate the side effects of sleep deprivation. One food that has caught many people’s attention because of its high flavonoid content and potential cardiovascular benefits is cocoa, the (usually) powdered product of chocolate “beans.” Flavanols (a subclass of flavonoids, which include catechins, epicatechins, proanthocyanidins, theaflavins, and thearubigins) have been found to improve endothelial function by increasing nitrous oxide availability (aiding in BP regulation). Hence, they might help increase cerebral blood flow and cognitive impairment. To date, many studies have shown an improvement of hippocampal functioning and cognition in general with a flavanol-rich diet, but none have studied whether flavanols in cocoa can diminish the impairments caused by restricting sleep. In a double-blind, randomized, controlled trial, Grassi et al studied whether cocoa could acutely improve cardiovascular and cognitive function after a night of sleep deprivation.

The study recruited 32 healthy participants (16 men and 16 women) with no history of medical, neurological, or psychiatric disorders. Participants all had a blood pressure of less than 140/90 mmHg and a body mass index (BMI) between 19-30 kg/m². The researchers excluded smokers, habitual cocoa consumers, and subjects with sleeping disorders, metabolic diseases, or any major cardiovascular risk factor.

Each participant attended four testing sessions: two control sessions in which they were evaluated after undisturbed sleep and two experimental sessions in which they were evaluated after total sleep deprivation. Testing sessions were separated by one week and participants were asked...