The elixir of life: green tea or red wine? Green tea, steeped in an ancient civilization, conquered the West because of its supposed health effects. Wine, particularly red wine, is a relative newcomer to the health scene. Tea leaves and red grapes are said to line the path to a long and healthy life. The evidence, however, is not convincing

Hot infusions of the leaves of Camillia sinensis have been used in China for "thousands of years," supposedly discovered by emperor Shen-Nung in 2737 B.C. He accidentally dropped a few leaves into boiling water, and the warm drink made him feel better. Tea drinkers outside Asia prefer black tea, made by roasting and fermenting the leaves. Tea contains caffeine, which stimulates the central nervous system. It is also a diuretic and a respiratory stimulant. That a warm cup of tea can "perk you up" has a firm physiological basis. This is also true for other caffeine-containing stimulants, like coffee or cocoa, but tea boasts that romantic history of an ancient emperor fumbling with tea leaves and hot water.

Initially, green tea became important in human health because of the stimulating effect of caffeine; the emperor did not know about antioxidants. Today, antioxidants in tea, particularly green tea, are said to protect us from cancer. Why? Notwithstanding high rates of cigarette smoking, the tea-drinking Chinese have one of the lowest lung cancer rates in the world.

But what about the other killer, heart disease? Green tea research makes no mention of our hearts at all. Well, it appears we just have to drink more. Red wine this time, another beverage rich in antioxidants. That is because of the French. They eat a rich diet with butter and creamy cheeses like Camembert and Brie, and according to a French diet writer, few or no vegetables (Montignac 1998). Yet the French enjoy the lowest rate of heart disease among Western countries. Apparently, this so-called French Paradox is explained by the French custom of drinking wine with their meals (Renaud and de Lorgeril 1992).

The wine antioxidants occur mostly in grape skin, so only red wine, which is fermented "on the skin," will do. However, the antioxidants in green tea are close chemical relatives of the antioxidants in red wine. So the real paradox is this: antioxidants in green tea specifically protect the Chinese from lung cancer while other, very closely related antioxidants in red wine specifically protect the French heart. Obviously we must drink both green tea and red wine. And, according to other nutrition authorities, we already need three glasses of milk and six glasses of water a day. This could give a whole new meaning to "being on a liquid diet." The question is, how solid is the evidence?

Antioxidants

There is no question about the antioxidant properties of some green tea constituents like epigallocatechol gallate (EGCG). Like many other plant extracts, green tea inhibits growth of cancer cells in the lab and in some rodents, but studies on humans are quite inconclusive. In fact, a meta-analysis of some thirty studies mentions several reports that link green tea consumption with an increased incidence of some cancers (Bushman 1998).

On the other hand, the French Paradox has become a popular overlay on the picture of the much-studied Mediterranean diet, which is rich in antioxidant-containing vegetables, like cabbage and tomatoes, unsaturated fats like olive oil, and wine (Matalas et al. 2001). This diet is said to decrease the incidence of heart disease and promote longevity. The French Paradox made the benefits of red wine into nutritional doctrine. Resveratrol, the main antioxidant in red wine, may even protect against cancer (Jang et al. 1997), although it can also promote atherosderosis (Wilson et al. 1996).

As is the case with the green tea literature, there is also disagreement on the wine story. Some reports mention increased antioxidant activity in blood serum after red wine consumption (Maxwell et al. 1994), while others suggest it is just the alcohol, independent of the type of beverage, that does the trick (Klatsky et al. 1997). So, the paradox remains. Surely if antioxidants protect the Chinese from lung cancer and the French from heart attacks, we would also expect the Chinese to have fewer heart attacks, and the French to have low lung cancer rates. And shouldn't both the Chinese and the French live longer than the rest of us?

Reading the Numbers in the Tea Leaves

Experts in tea, wine, and the Mediterranean diet often mention higher life expectancies and frequently make claims of exceptional longevities. These numbers can be measured and are available in several places. The United Nations publishes a vast amount of information on many aspects of human life. The forty-eighth issue of the United Nations Demographic Yearbook (1996) concentrated on mortality statistics.

Unfortunately, the life expectancy statistics are not very helpful. The Yearbook's table 4 gives us male and female life expectancy at birth. When we follow the example of some actuaries and average the male and female numbers to get a less complex picture of unisex data, we see that Mediterranean Greece and France don't particularly stand out from other industrialized countries. The tea-drinking Japanese are indeed at the top but the tea-drinking Chinese rank last.