**6. Health importance of tea antioxidant properties**

In this write-up, I will highlight the oxidative impact of tea polyphenols on cancer, cardiovascular conditions, neurodegenerative disorders, diabetes, and their role in boosting fertility in human beings.

### **6.1 Cancer**

The role of EGCG, as an active compound of green tea, is to deter and ameliorate disease courtesy of its antioxidant and anti-inflammatory properties, in conformity the with a validated myriad of study findings. Scientists have proven the effectiveness of this green tea compound in the inhibition of carcinogenesis processes in many types of cancer, though it is still under investigation for effectiveness in other types. Furthermore, catechins are effective in modulating the complexity of chemical processes in the mitochondrion and act in synergy with chemotherapeutic agents to reduce toxicities and anti-carcinogenic outcomes [12, 35, 39, 41]. **Figure 5** shows the spectrum of EGCG action on numerous cancer sites.

Besides hampering the accumulation of ROS in human bodies to prevent cancer, EGCG also blocks the DNA synthesis of cancer cells without interfering with the

*Considering the Antioxidant Properties of Tea to Improve Human Health DOI: http://dx.doi.org/10.5772/intechopen.107148*

**Figure 5.** *Role of EGCG in the inhibition of numerous types of cancers [41].*

division of normal body cells [10]. In an experiment aimed at establishing the role of EGCG in stimulating hepatocytes in goats, findings revealed efficacy in promoting cell proliferation, improving the integrity of cell membranes, and cell endurance and function under stress from oxidation, [10, 35].

More findings by Niedzwiecki et al. [42] from several other experiments agreed that tea polyphenols, in combination act synergistically to inhibit tumor growth and metastasis, thus efficacious if used against multiple targets and levels of cancer development and progression, and thus, could be a safe and efficacious approach in cancer prevention and therapy.

Given the numerous findings, scientists recommend that medics could use the synergistic competence of tea catechins with anticancer medications to support therapy as well as cancer prevention [43]. Almatroodi et al. [41] further contend that the combined therapy helps to enhance more anti-cancerous activity and reduction of toxicities by the mitigation of the after-effects sometimes witnessed during single chemotherapy use, which though efficacious in the treatment of cancer, and causes adverse side effects, including malaise, hair loss, infection, nausea, and vomiting, appetite complications, mood swings, and changes in physiologic and biochemical processes Tang et al. [44]. See **Figure 6** for illustration.

Further findings from clinical trials as discussed by Musial et al. [35] produced interesting results which portrayed a positive response when Polyphenon E was administered as a supplement, consisting of thriving catechins: EC, EGC, ECG, and EGCG to patients with carcinoma effectiveness. Each capsule contained a decaf EGCG mixture with 200 mg content. During the first phase of the experiment to determine the required dose of EGCG, investigators established a limit of 1200 mg EGCG as a thresh hold for future safety. They also discovered that effective prevention against colorectal adenocarcinoma required consuming ten cups of tea of 150 milliliters each per day.

Other findings from reviews of *in vivo* and *in vitro* studies by Tang et al. [44] recommended the consumption of five cups of tea per day for four weeks to achieve anticancer effectiveness. Also, oral bacteria that could be a causative agent in oral

**Figure 6.** *The most molecular target of tea on targeting cancer [44].*

cancer would be neutralized by drinking five cups of infusion tea extracted from two grams of tea daily for six months; this practice also applies to reducing oxidative stress and stopping the initiation of prostate cancer. However, a warning based on findings from an isolated study indicated an increased risk of developing bladder cancer when one consumed five to nine cups of tea per day [35].
