For the past several years, the popularity of slimming teas (most commonly, that of the Chinese green tea) as an effective weight-loss tool has grown exponentially. Everyone from dieticians to movie stars and athletes seems to be swearing by its many benefits.
However, as trends go, this one cannot be dismissed as just a fad, because people in China and India have been consuming green tea for thousands of years and even using it in traditional medicines. That it offers several health benefits is beyond doubt, but to assume that green tea is really the magic potion to end all health problems may be a bit premature.
For starters, green tea’s anti-carcinogenic qualities come chiefly come from polyphenols, which have been shown to decrease tumors in laboratory studies, by inhibiting two proteins that promote tumor cell growth and migration. Research also suggests that for each additional two cups per day of tea consumed, the risk of developing Type 2 diabetes dropped by 4.6 percent. A Chinese study published in the Archives of Internal Medicine also showed a 46%-65% reduction in hypertension risk in regular consumers of oolong or green tea, as compared to non-consumers of tea. Daily consumption of green tea may also be good for your eyes, according to this study, due to the presence of catechins, an antioxidant in green tea.
But let’s get to the point. The main reason why green tea is so popular worldwide is largely due to its supposed metabolism-boosting, calorie-burning properties. Although evidence has shown that green tea extract may be an effective herbal remedy for weight control in overweight and obese adults, the actual weight lost in the studies were quite minimal. This brings us to…
A lot of the hype surrounding green tea disappears when you take a closer look at scientific evidence. Most studies pointing to green tea as a weight reduction tool either report really insignificant amounts of loss or are not tested on humans at all. There are also several recent scientific studies claiming that green tea flavanols can lower the risk of dementia and Alzheimer’s but the actual link between the two is weak, and calls for further study. Green tea’s anti-carcinogenic properties have also been put to test: A 2009 review of 51 different studies, consisting of over 1.6 million participants in total, found that “evidence of a link between green tea and cancer was weak and highly contradictory,” even as it concludes that “drinking green tea appears to be safe at moderate, regular and habitual use”.
A 2001-study further reported that green tea extract reduces the absorption of iron by 25%; while the presence of tannin reduces the absorption of folic acid, which plays an important role in preventing birth defects. Pregnant women and anemic patients should therefore watch their intake of green tea carefully and possibly under medical supervision.
Okay, there’s nothing ugly about green tea but too much can be dangerous, as per this report of a teenage girl who drank three cups a day for three months in a bid to lose weight, and contracted acute hepatitis. While the authors of her medical report maintained that “green tea is predominantly a very safe and healthy drink”, they also indentified her particular source of imported Chinese green tea as a “causative agent” and asked her to stop drinking it immediately.
To sum it up, green tea while not inherently harmful is not a miracle cure-all either. Our bodies adjust differently to different foods and this is no exception. As long as we keep our intake moderate and watch out for side effects, a cup of green tea every now and then can safely continue to be a part of our lives.