There has been recently a lot of news concerning green teas.
Green tea, which has been reported to have anticancer properties and to raise levels of antioxidants in the blood that may ward off heart disease, now appears to have the potential to promote weight loss. Preliminary lab tests in mice put forth the ability of green tea in weight loss by burning of calories and fat needed to lose weight.
Health hazards of green teaBut there are some disadvantages linked to the use of green for weight loss. Some people might tell you that green tea is the be-all-end-all for weight loss success. This means that you can’t go on consuming unlimited calories and drink a cup of green tea with the hope of making it all go away. It is important to realize that a healthy diet and increased exercise will go a long way in helping you lose weight and keeping it off.
Caffeine in green tea might prove harmful for people with heart problems, high blood pressure or stimulant sensitivities. Such people can try taking green tea extract. Most green tea extract is made from decaffeinated green tea so you can still get the weight loss benefits without the caffeine. It is wise to consult a doctor before starting green tea for weight loss.
Benefits of green tea for weight loss
Impact of green tea on metabolismGreen tea contains powerful antioxidants called catechin polyphenols that are responsible for many of the health benefits of green tea. Catechin-polyphenols, in particular epigallocatechin gallate (EGCG) and caffeine that naturally occur in green tea work synergistically to stimulate thermogenesis and augment and prolong sympathetic stimulation of thermogenesis. Thermogenesis is the process of the body burning fuel without making chemical energy and the calories are released as heat.
The researchers from the American Journal of Clinical Nutrition concluded that that green tea extract has been shown to increase 24-hour energy expenditure and fat oxidation, and over a 24-hour period, green tea extract increases the metabolic rate by 4%. It is also important to note that researchers found that the combined ingredients of green tea were much more effective at this process than just caffeine by itself.
Impact of green tea on fat absorption and glucose regulationGreen tea catechins can help prevent obesity by inhibiting the movement of glucose in fat cells. EGCG has been found to be especially effective. Green tea also acts as a glucose regulator. It causes carbohydrates to be released slowly, preventing sharp increases in blood-insulin levels. This promotes the burning of fat.
Also, green tea contains three major components i.e. catechins, caffeine and theanine that promote fat loss. Studies suggest that green tea compounds promote fat loss by inhibiting both gastric and pancreatic lipase, the enzymes that digest triglycerides, and fatty acid synthetase, the enzyme responsible for synthesizing fatty acids into the form in which they can be stored in the body's adipose cells.
Impact of green tea on appetiteLeptin is a protein produced by fats that appear to play an important role in managing fat storage in the body through brain signals. Years ago it was thought by scientists that lower leptin levels would increase appetite. However, current research has now found that it does just the opposite and decreases appetite. There is clear evidence that green tea polyphenols (EGCG) are a factor in depressing leptin as well as affecting other hormone levels important in regulating appetite.
A 2000 study conducted at the University of Chicago found that green tea caused rats to lose up to 21 percent of their body weight. Rats injected with a green tea extract lost their appetites and consumed up to 60 percent less food after seven days of daily injections. This may be due to the blood sugar regulating effects of green tea.
Impact of green tea on saving caloriesIn present times, the calories that we ingest just to get our morning caffeine are wreaking havoc on our waistlines. If you intend to save these mega-calories in the morning but still get your caffeine fix, try substituting green tea for coffee. There will definitely be difference in your waistline in a few weeks.
So, stop drinking coffee and soft drinks and switch to green tea exclusively. You will thus get a healthy dose of powerful antioxidants while simultaneously dropping the calories and sugar.
Impact of green tea on longer exerciseExercise burns calories (by engaging in physical activities), boosts metabolism (as energy levels are raised on doing physical exercise) and increases muscle mass (as exercise develops lean muscle mass). The catechin polyphenols in green tea appear to stimulate the use of fatty acids by liver and muscle cells. This subsequently reduces the rate that carbohydrates are used and allows for more endurance and longer exercise times. In fact, a study using green tea extract on lab rats increased the amount of time the animals could swim before becoming exhausted by as much as 24%.
To match the beneficial effect on test animals' endurance capacity seen in the experiments, the researchers estimated that a 165-pound athlete would need to drink about 4 cups of green tea daily.
Green tea may ward off weight gainAccording to preliminary lab tests in mice, the benefits of green tea might include blocking fat, improving metabolic rate, regulating blood sugar, suppressing appetite and keeping extra pounds at bay.
But there's no proof yet that sipping green tea will do the same for human beings. Researchers suggest that while the work is interesting and put forth the findings that compounds in green tea other than caffeine are involved in thermogenesis and weight control, caution should be used in interpreting animal data and applying it to humans. And until better clinical trials are done to humans, it is hard to indicate the physiological significance of green tea in humans.
Researchers also suggest that green tea can't be used, and it shouldn't be used, as a 'magic bullet' for weight loss. It must be combined with other changes, including increasing physical activity and reducing a high-calorie diet.