A snippet from the just released October JASS:
Tea and olive oil
Tea is made from the leaves of the Camellia sinensis plant. There are basically three kinds of tea - green, oolong and black tea - three billion kilograms of which are consumed each year which makes tea the most popular beverage in the world.
Green tea contains polyphenols which have a theoretical role in the prevention of cardiovascular disease, but it is unclear if this has any effect on tea drinkers in the real world. To test the effects, Kuriyama et al (JAMA 2006;296:1255-65) followed 40 000 Japanese adults for a decade and related their mortality rates from cardiovascular disease to their tea consumption.
They found the more green tea people drank, the lower their risk of dying from cardiovascular disease. There was a “dose-related” response and the effect was more marked in women. The strongest association was with a decrease in stroke mortality. There was no link with cancer mortality.
And while on the subject of polyphenols, it appears that virgin olive oil is better than refined olive oil when it comes to raising your high-density lipoproteins and decreasing your oxidative stress markers. Covacs et al (Ann Int Med 2006;145:333-41) showed that taking an unrefined olive oil supplement as opposed to a refined olive oil one, positively affected serum markers of good cardio-vascular health. These effects were in addition to olive oil being a monounsaturated fat, so it seems the Mediterranean diet using virgin olive oil is underpinned by solid science.
