Green Tea to Lower Cholesterol? Not So Fast
Does Green Tea Lower Cholesterol?
All right, this green tea article has been hanging over my head for at least a month now.
I just couldn't get motivated to wade through all the research to determine if yes, this is an effective way to lower cholesterol and预防心脏病, or no, it's just a lot of hype.
好吧，我今天坐下来整理它，这就是我发现的。
Health Clai
The proposed health claim for green tea is that drinking at least 5 fluid ounces as a source of catechins may reduce risk factors associated withcardiovascular disease.
What are catchins?
Green tea contains catechins, which are a type of flavenoid with antioxidant properties.
抗氧化剂缓慢氧化过程。
LDL分子的氧化是斑块形成的结果。因此，增加抗氧化剂摄入量应该缓慢氧化LDL., resulting in less arterial plaque formation.
而且，当分子被氧化时，释放自由基损伤细胞。
这些自由基可以增加与心血管疾病相关的炎症问题。
皮肤病如何工作
身体将黄素素作为异物颗粒识别，并用于消除身体的原因。
Flavenoids themselves do not act as an antioxidant and they are poorly absorbed by the body.
However, the proposed benefit of extra flavenoids is that as the body eliminates the unwanted flavenoids, damaging free radicals are also eliminated.
Tea productio
The various types of tea are produced differently.
乌龙茶和红茶的叶子被允许氧化（茶叶中的酶变化到较大的分子）。
绿茶未被氧化，但通过蒸汽鲜切片产生的，酶被灭活并且发生较少的氧化。
The least processed tea is white tea, which contains the highest levels of catechins.
绿茶含有第二高的儿茶素水平，每份约125毫克儿茶素（或〜25％的新鲜茶叶）。
Here's a little breakdown on tea oxidation:
Black tea - Highest oxidation; also, highest caffeine content and strongest flavor; 90% of all tea served in the West is black tea
Oolong tea - 10-70% oxidized
绿茶——oxidati低on
White tea - Minimal oxidation; Uncured, unfermented; Lower caffeine content that other teas
FDA Revie
In 2005, the FDA did not approve the health claim for green tea, because the link between green tea and reduced cardiovascular disease risk was too weak and more conclusive evidence was needed.
Recent Research
This past June, 2008, a study was published that links green tea to reduced flow-mediated dilation of brachial arteries (major blood vessels in the upper arms).
Flow-mediated dilation is related to coronary endothelial function and is an indicator for cardiovascular disease risk.
Increased dilation is good.
这意味着心脏必须在整个循环过程中减少血液。
(The endothelium is the inner layer of an artery, which blood flows against.)
这是对14个健康个体的研究，消耗了6克绿茶，然后是流量介导的扩张。
The results showed an increased flow-mediated dilation with tea (peak at 30 minutes post consumption).
There was no change to antioxidant status after consumption.
It's proposed that the improved flow-mediated dilation is how green tea reduces cardiovascular disease risk.
炒作
自本研究于6月份发表以来，我遇到了多个文章，头条新闻尖叫着“绿茶防止心脏病”。
I think there is significant research that still needs to be completed before it can be determined for sure how tea works to prevent heart disease.
A study of 14 individuals is a small study.
Drinking 6 grams of green tea, would equal about three - 6 ounce cups of green tea each day.
(Based on making 1 six ounce cup of tea with 1 teaspoon or 2.25 grams of green tea.)
However, the study results are based on consuming 6 grams of tea in one setting followed by improved flow-mediated dilation at peak levels 30 minutes after consumption.
How likely is it for you to drink three cups of tea quickly, back-to-back to reproduce the short-term benefit shown in this study?
To me, that is not a very effective way to reduce心脏病风险.
但是，如果你喜欢绿茶 - 喝它。
Many studies are showing that green tea is beneficial to heart disease.
The what, how, and how much is yet to be determined.
Who knows what future studies will find?
