In late 2004, an episode featuring Dr Nigel Perricone aired on The Oprah Winfrey Show. Mr Perricone has written a number of books including the Perricone Prescription, that relate to diet and health (the main premise of his diet is improving skin condition).
Dr Perricone said some interesting things about green tea, which has inspired some aggressive marketing.
Here is the original transcript from the Oprah show:
Oprah: Now I’ve read in your book that you said if I just replaced coffee with green tea instead, that I could lose 10 pounds in six weeks.
Dr. Perricone: Absolutely.
Oprah: Now really. How could that — what is the big deal about this?
Dr Perricone: Coffee has organic acids that raise your blood sugar, raise insulin. Insulin puts a lock on body fat. When you switch over to green tea, you get your caffeine, you’re all set, but you will drop your insulin levels and body fat will fall very rapidly. So 10 pounds in six weeks, I will guarantee it.
Oprah: I’m gonna do that. OK. That is so good! Whoo! That is great.
— The Oprah Winfrey Show: “Look 10 Years Younger in 10 Days” – Nov 10, 2004
Perhaps the doctor got a bit over exuberant – guaranteeing anyone’s weight loss is a risky thing to do. But what about green tea? There is no doubt that green tea has numerous health properties. You can go search through study after study, and discover the enormous body of evidence indicating green tea’s healthful properties.
Green tea and weight loss? It isn’t hard to come up with a study or two. One of the most cited articles is this one, that summarizes “Green tea has thermogenic properties and promotes fat oxidation beyond that explained by its caffeine content per se”.
As for the coffee there seem to be many contradictions – some raised by this recent study into the affects of caffeine on insulin. The researchers did point out that coffee is a different beast to caffeine – “When you give somebody caffeine without all of the other substances that are in coffee you have a very different situation,”.