There are many claims about the health benefits of green tea, especially for those trying to lose weight. Though green tea has been used for thousands of years and its health benefits have been widely documented, there are side effects attached to its use in weight loss.
Contrary to what many people believe, green tea does contain caffeine. Depending on the brewing method, green tea has 24 to 48 mg per cup. According to the University of Maryland, if you are replacing meals and other liquids with green tea in the belief that it will speed weight loss, you run the risk of dizziness, heart palpitations, insomnia and irritability.
It is possible to actually overdose on caffeine. If you experience abdominal spasms, appetite loss, diarrhea, headaches, nausea and vomiting, stop drinking green tea and contact your health care provider.
Drinking plenty of water is necessary to anyone wanting to lose weight, because a dehydrated body will hang onto every extra ounce of fat. According to Dr. Andrew Weil, you cannot substitute green tea for water as you lose weight. Caffeine is a diuretic, so you are losing water from your body even as you drink the green tea.
Your body needs about eight cups of water a day. Dr. Weil explains that you need to drink three cups of tea to get two cups of water. Unless you are drinking twelve cups of tea a day, you run the risk of dehydration, which can lead to serious heart problems.
And drinking twelve cups of tea a day--even weak green tea--puts you in danger of caffeine poisoning.
Not all green teas used by people trying to lose weight are pure. Some contain blends of other herbs, including senna--a natural laxative. According to Dr. Mark Bayatsky at EveryDayHealth.com, use of senna can lead to diarrhea. If you continue using a green tea weight loss blend that contain senna, the production of necessary neuropeptides can stop, which leads to chronic constipation.
Even pure green tea can cause nausea, because the tannins it contains interferes with your body's absorption of iron, which can also lead to anemia.
Green tea is also acidic which can irritate the stomach lining and aggravate a peptic ulcer.
Anytime you reduce your caloric intake, you run the risk of not getting all of the vitamins, minerals, amino acids, proteins, carbohydrates and healthy fats that your body needs.
Drinking green tea instead of eating as a part of your weight loss plan can actually rob your body of the nutrients it needs, leading to malnutrition.
Malnutrition can cause your body to start taking nutrients from your muscles, bones and organs, severely weakening them. According to the entry in The Physician's Desk Reference, malnutrition can also cause irritability, dry or patchy skin, hair loss and brittle nails.
Aluminum and Fluoride
All rapid weight loss puts a strain on the body, making it more susceptible to problems.
Studies, such as one published in the European Journal of Nutrition December of 2007, have found a troubling link between the aluminum content of green tea and low iron levels in rats. According to Oregon State University, green tea also contains fluoride. There are also concerns that the combination of the two could pose a health risk; but many more studies are needed.