It's Good To Be Green

These days there seems to be a continuous message about the importance of "going green." While "going green" may be crucial to preserve our external environment it may also be paramount in conserving our internal environment. We have always heard about consuming adequate volumes of our GREEN vegetables to maintain iron and folic acid levels but there is also a GREEN beverage that has shown some health promise-Green Tea. As I have stated before in this blog, the premise of my writing these entries is a doctor taking his own advice. Since I have been trying to substitute green tea for coffee over the last year or so, not always successfully, I figured it was time to review the literature and pass it on to you all.

The last entry focused on supplements, specifically Vitamin D and omega-3 fatty acids, that have shown proven benefit in clinical trials and from my literature review green tea also has demonstrated impressive health results. After all, as I have alluded to before it is expensive to maintain our health these days so we only want to invest in products that are evidence based.

Green tea's health benefits are primarily based on its rich content of flavonoids, specifically catechins and their derivatives. Epigallocatechin-3-gallate (EGCG, since I refuse to type out the long version again in this entry) is a potent anti-oxidant (similar to Vitamins C and E) which scavenges free radicals in the body. Free radicals are basically a result of stress on the cellular level that can destroy various tissues in the body and lead to harmful conditions such as cancer, heart disease and diabetes.

Over the last few years some of the major medical journals have covered this green tea story. In 2006 in the European Journal of Clinical Nutrition a published study found that green tea is healthier than any other beverage, including water, because not only does it rehydrate but it also contains a rich supply of polyphenols protective against heart disease. Additionally, a 2006 Japanese study in JAMA suggested that drinking green tea lowered death due to all causes, including cardiovascular disease. That is pretty significant!

I am currently overwhelmed by the amount of research on green tea as I try and squeeze the pertinent information into this entry which is intended to be a quick read. Some other benefits suggested include lowering LDL (bad cholesterol), preventing blood clots, protecting the heart and brain during acute attacks (myocardial infarction and stroke), protection against cancer, weight loss and control of diabetes. As a physician and human being I am interested in all of these but I will focus on weight loss and diabetes since this is my career path.

We have previously discussed the importance of avoiding insulin spikes throughout the day to prevent weight gain. This is primarily achieved by eating frequent small meals that are high in protein and less simple sugars (processed foods). Well studies have shown that insulin is more effective in lowering blood glucose in the body when the diet is supplemented with green tea. For example, in a study whereby one group of rats ate a diet rich in high fructose corn syrup and the other group had the same diet but with the addition of green tea over 12 weeks it was found that the group with green tea supplementation had lower blood glucose, lower blood pressure and lower insulin levels than the other group. Maybe I should have been drinking green tea with my burgers and fries all these years!

It is only recently that I learned the difference between good fat and bad fat by working on a research project. Most of us have heard about the apple shape versus pear shaped obesity in terms of risk factors, or the term "skinny fat." The apple shape essentially means a high amount of abdominal fat (visceral fat) which is more metabolically detrimental because there is more turn over of cholesterol and higher insulin resistance. Actually peripheral superficial fat (the thighs, butt, arms, etc.) are protective because they serve as a cholesterol depot which means that there is a lower amount of fat circulating in the blood that can cause heart attacks, etc. Green tea has been shown to not only promote overall body fat loss, but specifically visceral fat (the most risky).

As any good doctor should do I must provide some warnings about consuming green tea. Green tea may lower the absorption of warfarin (coumadin-a common blood thinner), pseudoephedrine and codeine. Also should be cautious in those with iron deficiency anemia and limited in the first trimester of pregnancy. If you require high levels of caffeine to function then you will need to consumee double the green tea than coffee since there is about 1/2 the caffeine, although you will be very well hydrated and healthy! All this information is available on-line if you have further concerns.

I have thoroughly enjoyed writing these entries as I am learning valuable information through this process. Please continue to spread the word if you are enjoying and encourage people to sign up for email updates. Hopefully we can make an impact on the health of others through continuing to learn and educate.