Anti-Cancer Foods... Part 2

Yesterday I received my new bed! OMG! What an amazing difference that made. When my brother and I went looking at beds... he bought me mine for my birthday 'cause he's the best brother ever... the salesman was appalled. He asked my brother, "Well, how old is your mattress?" We told him that it was the same mattress and box springs that my brother had used as a kid so they must be a good 40+ years old. The guys jaw dropped, he shook his head and said "I'd say it's about time you got a new one." I was all laughing at my brother until I realized the mattress I had was a hand-me-down from a friend and that my mattress was just as old as my brothers. Maybe that's why it was all lumpy-bumpy and had a divot in the middle that you rolled into every night. Did you know you're supposed to turn or flip your mattress regularly? Sad, sad, sad. I've been so mattress ignorant all these years.

So back to our discussion about phytochemicals that help fight cancer. I believe we left off at tumeric.

Green tea contains catechins. More specifically, it contains the all important catechin called epigallocatechin gallate. Since this is way to long and difficult to pronounce much less remember, we'll just use the acronym EGCG. EGCG has been demonstrated to inhibit the growth of cancerous cell lines, especially bladder and prostate cancers. It also inhibits the formation of blood supply to tumors.

Just because I think it's interesting, I'm going to go into depth about how tea is grown and prepared so you can understand the importance of the next bit of data. Teas, like most plants, are affected by soil composition, climate and preparation of the tea leaves themselves. Although there is some variation in tea plants the most important variable is how it is processed. Processing style is what determines if a tea is green, yellow, white, oolong, black, etc.

 

The step of greatest importance is the oxidation step. Oxidation is highly important in the formation of many taste and aroma compounds that give a tea its liquid color, strength and briskness. Oxidation also determines the level of preservation and phytochemical destruction. Black teas undergo 100% oxidation which allows them to retain their flavor for many years. They account for over 90% of all teas sold in the West. The downside to black tea is that all the EGCG has been oxidized out. For oolong teas there may be anywhere from 5-70% oxidation depending on if it is a light or dark variety. Of all the teas, green tea undergoes the least amount of oxidation. The oxidation processes for green tea is halted by the quick application of heat after leaf picking, either with steam (Japanese method) or by dry cooking in hot pans (Chinese method). When done correctly the tea retains most of the chemical composition of fresh leaves - the all important phytochemical EGCG!


When different green teas were evaluated, the Japanese green teas contained massively more EGCG per gram of tea than any others. That said, it must be high quality Japanese green tea. The two that demonstrated the highest levels were the Gyokuro and Sencha  teas. Gyorkuro tea is a darker green as it is cultivated in the shade, while the Sencha tea is cultivated in direct sunlight and is a lighter green color. These delicate leaves are damaged by boiling water, so they must be steeped in water no warmer than 175 degrees F or it will add a bitter flavor to the tea. I haven't tested this theory yet. According to the book, to maximize the EGCG one must brew the tea for 8-10 minutes. This will provide the drinker with 540 mg of EGCG/cup of tea. If the tea is steeped <5 minutes, the EGCG is decreased to 108 mg/cup. The tea sellers were appalled at the idea of brewing green tea longer than 1 minute and claimed that the tea would be unpalatable with that much steeping. I cannot agree with them. It taste's just fine to me... but then I'm not a tea connoisseur either.

So there you have it. Three cups per day of high quality Japanese green tea steeped 8-10 minutes in 175 degree F water.

Anti-Cancer Foods... Part 3 coming soon to a blog near you!