Once again, green tea is in the news. This time, researchers have discovered that certain chemicals found in green tea may be able to protect against the cognitive problems that occur in people who have obstructive sleep apnea (OSA). The numbers of people with sleep apnea are recognized as being quite large, with few people actually seeking out treatment or help from doctors.
The new study published in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine shows that green tea polyphenols (GTP), administered through drinking water to rats who were intermittently deprived of oxygen during their 12-hour night cycles gave the rats a level of protection that other rats did not have.
People with sleep apnea have increased markers of oxidative stress and exhibit significant changes in their brain tissue in areas involved in learning and memory. Rats produce similar neurological deficit patterns when they are subjected to the intermittent loss of oxygen that mimics this sleep apnea.
GTP, the chemical in green tea, is known to possess anti-oxidant properties, acting as a free radical scavengers, and research has shown that the compounds may reduce the risk of a variety of different diseases.
“Recent studies have demonstrated the neuroprotective activity of GTP in animal models of neurodegenerative conditions such as Parkinson’s and Alzheimer’s disease,” wrote Dr. Gozal, lead author and professor at the University of Louisville.
In this study, the researchers divided 106 male rats into two groups that underwent intermittent oxygen depletion during the 12-hour “night” cycle for 14 days. One group received drinking water treated with GTP; the other received plain drinking water.
They were then tested for markers of inflammation and oxidative stress, as well as for performance in spatial learning and memory tasks—namely a water “maze” in which the rat had to memorize the location of a hidden platform.
The rats that received the green tea-treated water performed significantly better in a water maze than the rats that drank plain water. Dr. Gozal writes that GTPs “may represent a potential interventional strategy for patients” with sleep-disordered breathing."