 Tea consumption is associated with a reduced risk of heart disease, stroke, and premature death in general, with each additional cup of green tea a day associated with a 4% lower mortality risk. So maybe drinking several cups of tea daily can keep the doctor away, as well as the mortician. But what about cancer? There is growing evidence from laboratory population and human interventional studies that tea can exert beneficial disease-preventive effects, and further may actually slow cancer progression. Let's review some of that evidence. Not only do those who drink a lot of tea appear to live years longer than those who drink less, drinking lots of tea may delay the onset of cancer. These are in Japanese tea cups, which only contain half a cup, so the highest category here is greater than or equal to five full cups of tea, not ten. The women who did get cancer appeared to get it seven years later if they'd been drinking lots of tea compared to those who consumed less, whereas men had a three-year delay, the difference male versus female potentially due to smoking habits. Green tea may be able to interfere with each of the stages of cancer formation, the initiation of the first cancer cell, promotion into a tumor, and then the subsequent progression and spread. Drinks often initiated when a free radical oxidizes our DNA, causing a mutation, but within 40 minutes of drinking green tea, you can get a nice spike in the antioxidant power of your bloodstream. This increase, in turn, made lower oxidative damage to DNA and so decreased the risk of cancer. Furthermore, in terms of genome-protective effects protecting our genes, pre-existing oxidation-induced DNA damage was lower after drinking green tea, suggesting that it can boost DNA repair as well. But we didn't know for sure until now. There's a DNA repair enzyme in our body called OGG1, and within one hour of drinking a single cup of green tea, we can boost its activity. Though after a week of tea drinking, we can boost it even higher, so regular intake of green tea may have additional benefits in the prevention and or repair of DNA damage. Tea is so DNA protective, it can be used for sperm storage, for fresh samples, until it can be properly refrigerated. And so anti-inflammatory, it can be used for pain control as a mouthwash after wisdom tooth surgery. And in terms of controlling cancer growth at a dose of green tea compounds that would make it into someone's organs after drinking six cups of tea, it can cause cancer cells to commit suicide. Apoptosis, programmed cell death while leaving normal cells alone. There's lots of chemo agents that can kill cancer through brute force, but that can make normal cells vulnerable too. So green tea appears to be potentially an ideal agent for cancer prevention. Little or no adverse side effects, efficacious for multiple cancers at achievable dose levels, can be taken orally. We have a sense of how it works by stopping cancer cells from growing, causing them to off themselves. It's cheap and has a history of safe acceptable use. But this was all based on in vitro studies in a test tube. It needs to be evaluated in human trials, give people with cancer green tea to see if it helps. Which we'll explore next.