Dr. Geo Espinosa | Sep 27, 2012 | Comments 1
Over the years, there have been dozens of studies pclaiming the health benefits of green tea, along with some reports that have dismissed the claims.
Now a new review of the clinical evidence related to green tea and health has just been published, so it seems like a good time to look at the role green tea can play in men’s health. First, however, let’s explore the basics of green tea.
What’s Special About Green Tea?
Green tea comes from the same plant as black and oolong teas, Camellia sinensis, but it’s what tea producers do with the tea leaves that makes the difference among these types of tea. Oxidation is the process that alters the chemical makeup, appearance and flavor of tea leaves. Both black and oolong teas are processed in a manner that breaks down the cell walls and triggers enzymes to cause oxidation. Leaves for green tea are not broken down in this way and are not oxidized. The absence of oxidation not only makes the taste and appearance of green tea different from those of black and oolong teas, but it also means green tea retains high levels of important plant substances called catechins.
Experts generally agree that the medicinal powers credited to green tea come from catechins. Although black and oolong teas (as well as apples, apricots, berries and chocolate) also contain catechins, green tea is an excellent source, including one catechin in particular: EGCG, or epigallocatechin gallate, which is credited as being the most powerful of the bunch.
Studies Of Green Tea And Health
In the latest meta-analysis, [1] eight studies on green tea and health were reviewed: two concerning cancer, two on weight loss and four on cardiovascular risk. The reviewers, researchers at the University of Bristol, reported several points of good news:
- “Positive evidence for risk reduction of breast, prostate, ovarian and endometrial cancers with green tea.” Numerous studies have looked at the effect of green tea on prostate cancer, and we discuss one of them below.
- “Green tea may reduce low-density lipoproteins and total cholesterol.” Men should be concerned about both of these factors, as they are risks for cardiovascular disease.
- A “considerable number” of trials suggest that “green tea does reduce body weight in the short term.” Being overweight or obese is associated with a wide range of health risks ranging from prostate cancer to heart disease, diabetes, gallstones, stroke and arthritis, among others.
Beyond this meta-analysis, other studies have examined the potential role of green tea in critical health issues. For example:
- In a large study involving 49,920 men who were followed for at least a decade, researchers examined the impact of drinking green tea on the risk of prostate cancer. They found that men who drank five or more cups of green tea per day had a lower risk of advanced prostate cancer when compared with men who drank less than one cup per day. [2]
- Catechins may also help men who have pre-cancerous prostate lesions called prostate intraepithelial neoplasia (PIN), a condition associated with a higher risk of developing prostate cancer. In a study of 60 men with high-grade PIN, half were given 200 mg of catechins daily while the other group received placebo. After one year, only one tumor had developed among the men who took catechins while 9 cases of prostate cancer were found in the placebo group.
- Although it’s a little soon to sing the praises of green tea for diabetes, a number of studies have examined its role and seen promising results. In one recent study in diabetic rats, the authors reported that “green tea reduced hyperglycemia [low blood sugar], prevented renal injury and autonomic dysfunction, suggesting reduced cardiovascular risk and target organ damage in diabetes.”[4]
- A study published in the International Journal of Epidemiology reported that risk of stroke, cerebral infarction and cerebral hemorrhage was reduced by 50 percent among people who drank several cups of green tea every two to three days.[5]
Enjoy Green Tea
Choosing to include green tea as part of your daily routine is an easy and delicious way to support your overall health. Enjoy green tea hot to start your day or cold with a lemon slice to cool down. Green tea makes a delicious smoothie as well as a unique slush.
Not all green tea is alike, and this applies not only to its taste but also to the amount of catechins in the leaves. If you want to get the most benefit — and the highest amount of EGCG — from your green tea, choose Japanese over Chinese green tea. A highly rated Japanese green tea is Matcha, which reportedly has about 10 times the amount of EGCG of other green teas. You can also enjoy the benefits of green tea in supplements, but be sure to talk to your healthcare provider before starting a supplement program.
Sources
[1] Green tea and green tea catechin extracts: an overview of the clinical evidence. http://www.ncbi.nlm.nih.gov/pubmed/22986087
[2] Green tea consumption and prostate cancer risk in Japanese men: a prospective study. http://aje.oxfordjournals.org/content/167/1/71.long
[3] Chemoprevention of human prostate cancer by oral administration of green tea catechins in volunteers with high-grade prostate intraepithelial neoplasia: a preliminary report from a one-year proof-of-principle study. http://cancerres.aacrjournals.org/content/66/2/1234.long
[4] The effects of green tea consumption on cardiometabolic alterations induced by experimental diabetes. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3299256/
[5] Consumption of green and roasted teas and the risk of stroke incidence: results from the Tokamachi-Nakasato cohort study in Japan. http://ije.oxfordjournals.org/content/37/5/1030.long
http://easyhealthoptions.com/mens-health/green-tea-for-mens-health/
