Green tea is made from the plant Camellia Sinensis’s leaves without fermentation (Suzuki, Miyoshi & Isemura, 2012) and is regarded as a popular and healthy drink in Asian countries because of its health-promoting potentials such as protecting against cancer and cardiovascular disease (Harvard Health Publications, 2012; Iwasaki et al., 2014). Lots of the positive effects are due to the antioxidative activity of (-)-epigallocatechin gallate (EGCG) which is a major component of green tea (Suzuki et al., 2012). And it draws researchers’ interests and attentions to further investigate. According to Suzuki et al., one example of the health advantages is that catechins in green tea bring an anti-obesity effect by stimulating lipid metabolism in liver (2012).
However, green tea may bring us undesirable outcomes due to some constituents. Caffeine is one of those substances that is diuretic and reduces the fatigue sensation but the consequences of overconsumption are well proved that it will decrease sleeping duration and worsen sleeping quality by inducing sleeplessness (Suzuki et al., 2012). A study found out that tea intake of university students was significantly linked to sleeping quality (Cheng et al., 2012). However, the types of tea were not investigated. The effect of green tea consumption on sleep quality is still not well documented.
Sleep is very important to our body for relaxation, preparing ourselves for the next day. Unfortunately, poor sleeping quality is prevalent in modern cities such as Hong Kong. An increasing number of university students have stated sleep problems. (Suen, Hon & Tam, 2008). Meerlo, Mistlberger, Jacobs, Heller & McGinty (2009) have reported that prolonged sleep loss may affect the rate of neurogenesis related to hippocampus-dependent learning. According to Meerlo et al. (2009), as memory formation can be disturbed by sleep deprivation, learning and memory processes are borne out by sleep. And it has been proved that poor sleeping quality and sleep debt have a correlation to poor academic performance which is bad news for students (Trockel et al., 2000, cited in Cheng et al., 2012; Mak, Lee, Ho, Lo & Lam, 2012; Curcio, Ferraraa & De Gennaro, 2006). As a result, the target group of current study is young adults who are community college or university students so as to see whether green tea affects their sleep.
Also, in Asian countries like China, drinking tea is a part of the social activities. We should pay more attention to the behavior of drinking tea especially green tea because of its increasing popularity and health benefits. According to Tseng et al. (2014), in spite of the higher popularity of drinking green tea consumption than coffee in Asia, many studies of caffeine intake on young adults are based on coffee drinking. This research is attempting to have a discussion on sleep quality, duration and green tea drinking habit among young adults.
The purposes of this research are to look into the behavior of...