I’ve previously written about green tea catechins but it was merely a brief overview. The benefits that this ingredient possesses is so extensive, I felt compelled to write a follow up article and explain exactly why this is in my health supplement daily regimen year round (regardless of some only using it during fat loss phases for its potential fat burning effects.)
Green tea leaves are comprised of four main compounds called catechizes (epigallocatechin-3-gallate (EGCG), epi-gallocatechin (EGC), epicatechin gallate (ECG) and epicatechin (EC.) Of these four, there is a reason why only one of them gets the spotlight. That being EGCG, mainly due to it having the most potency. Even though it is the most potent of all four of the catechins, it is still not extremely bioavailable in regards to human consumption. Due to the structure of these catechins, intestinal absorption is as low as 2% in humans (1.) It is because of these low absorption rates that two things need to happen in order to increase their bioavailability. Adding in an ingredient such as piperine (black pepper extract) has been shown to increase the absorption of EGCG drastically as well as taking EGCG on an empty stomach (2, 3, 4.) A study from Lee et al showed ingesting 400mgs and 800mgs of EGCG with only a light breakfast increased circulating levels of EGCG by roughly 92%. The more interesting part of this study was seen with the higher dose of 800mgs which showed an increased half life (5.)
Now that the basic pharmacokinetics of EGCG is understood, we can look into the benefits to supplementing with it. Like I previously said, the list truly does go on and on in terms of potential health benefits so we will stay within the framework of “why I chose to implement them year round” so you can better understand where I’m coming from. First and foremost is its anti-cancer properties. I think we can all agree that within today’s society, cancer and overall health disorders are at an all time high due to the nature of our environment. To me, anything I can use to help prevent anything of a cancerous nature from occuring, is more than worth its cost. These catechins effect cancer metabolism via telomerase inhibition, tNOX inhibition, induction of cellular apoptosis, and many other ways (6, 7, 8.) Although I havent seen conclusive literature to support all of these claims and to name it as a true anti-cancer agent, it still holds enough evidence to win me over. Moving forward into the second portion are its effects on fat mass and overall effects on body composition. A double blind study from Wang et al looked at the effects of catechin enriched green tea on body composition. They had four groups broken apart into low, moderate, and high groups. The low catechin group had 30mg catechins and 10mg caffeine. Two moderate catechin groups consisted of 460mgs catechins and around 115mgs of caffeine but undulating their frequency of use between groups. The final high catechin group consisted of 886mgs catechins and 200mgs of caffeine. They found that all groups decreased their waist circumference with the most changes noted in the high catechin group (9.)
As we are on the focal point of body composition, its also been shown to have favorable effects from a hormonal metabolism standpoint. Green tea can in fact inhibit the UGT2B17 enzyme. This is the enzyme which conjugates Testosterone into testosterone glucuronide (a less potent form) and can increase the active AUC of testosterone (10.) EGCG even further might have the potential to inhibit 5-alpha reductase, but the literature on this isn’t quite complete as its failed to do so in whole-cell cultures (11.) One bit of literature from Wu et al looked at the effects of 2 months usage of green tea in postmenopausal women, looking mainly at lipoprotein cholesterol, glucose, and hormone levels. There were no significant hormonal effects but there was a reduction in LDL cholesterol (10.) The reason I bring this study up in particular is because I wanted to show just how vast the research is on both sides of the “hormonal” equation. Pharmacokinetically it possesses the ability to do so. Now whether that truly takes effect in application can depend on personal metabolic rates, gender, age, and a host of other biological differences. To me, I feel it is worth noting as a possible benefit however.
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The last points I want to cover are its effects on fasting glucose levels and cognition. In regards to fasting glucose levels, the very interesting part is just how much of an interaction EGCG has with carbohydrate metabolism. It has been show to have favorable partitioning effects by suppressing adipocyte GLUT4 translocation and stimulating myocyte GLUT4 translocation. This was seen in a piece of literature from Hitoshi et al that concluded by saying “green tea modulates the glucose uptake system in adipose tissue and skeletal muscle and suppresses the expression and/or activation of adipogenesis-related transcription factors, as the possible mechanisms of its anti-obesity actions” (12.) This can mean that taking EGCG in a fed state may not be a bad idea. In regards to EGCG’s effects on cognition, we see it once again has the vast potential for overall learning and memory increases. EGCG very easily crosses the blood brain barrier. Once it does, brain activity is increasing for a few hours following ingestion. Park and colleagues actually looked at the popular combination of green tea extract and l-theanine (LGNC-07.) This was a randomized, double-blind, placebo-controlled study on the effect of LGNC-07 on memory and attention in subjects with mild cognitive impairment (MCI.) Ninety-one MCI subjects whose Mini Mental State Examination-K (MMSE-K) scores were between 21 and 26 and who were in either stage 2 or 3 on the Global Deterioration Scale were enrolled in this study. The treatment group (13 men, 32 women; 57.58 ± 9.45 years) took 1,680 mg of LGNC-07, and the placebo group (12 men, 34 women; 56.28 ± 9.92 years) received an equivalent amount of maltodextrin and lactose for 16 weeks. Neuropsychological tests (Rey-Kim memory test and Stroop color-word test) and electroencephalography were conducted to evaluate the effect of LGNC-07 on memory and attention. Further analyses were stratified by baseline severity to evaluate treatment response on the degree of impairment (MMSE-K 21-23 and 24-26). LGNC-07 led to improvements in memory by marginally increasing delayed recognition in the Rey-Kim memory test (P = .0572). Stratified analyses showed that LGNC-07 improved memory and selective attention by significantly increasing the Rey-Kim memory quotient and word reading in the subjects with MMSE-K scores of 21-23 (LGNC-07, n = 11; placebo, n = 9). Electroencephalograms were recorded in 24 randomly selected subjects hourly for 3 hours in eye-open, eye-closed, and reading states after a single dose of LGNC-07 (LGNC-07, n = 12; placebo, n = 12). Brain theta waves, an indicator of cognitive alertness, were increased significantly in the temporal, frontal, parietal, and occipital areas after 3 hours in the eye-open and reading states. Therefore, this study suggests that LGNC-07 has potential as an intervention for cognitive improvement (13.)
As it is abundantly clear, EGCG possesses more than enough reasons to give it a further analysis and possibly implement it into your own supplement regimen. From having possibly positive body composition effects to its anti-cancer, anti-obesity, positive blood pressure, decrease in insulin secretion, increased cerebral blood flow, and decreased glucose levels, it clearly has its place. As I’ve stated before, there are an endless amount of beneficial health supplements. I merely want to shed light on some of the ones I feel deserve more credit as well as a proper understanding before deciding or not deciding to utilize them.
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