Substances in tea: Caffeine

The benefits of appropriate usage of caffeine and the side effects of chronic over-dosage

People are giving up coffee for tea. One popular reason is for reducing caffeine intake. There could be a couple hundred mg of caffeine in the cuppa while it can be as little as 1 mg in tea (1).

Before we go further to discuss this topic, however, the reader has to be aware that moderate intake of caffeine is not a bad idea for most people. Especially for those who know how to use fine teas for their caffeine content.

Detox, fight Alzheimer’s and fatty deposits

After all, the presence of methylxanthines in tea, such as caffeine and theobromine, not only keeps you alert, but may very well help fight Alzheimer’s disease. Caffeine also relaxes the bronchial smooth muscle in the air tract, and therefore helps breathing. The materials are also diuretic. Passing waste liquids is critical in detoxification. The presence of theobromine is also associated with preventing formation of fatty cells in the human body (2). It is therefore a contributive element in tea’s health effects for waist line control and prevention for cardiovascular diseases.

Much work is still needed for a usable database of the caffeine contents of various teas. Tea type and quality have systematically been made unclear in most surveys and researches regarding health related contents in tea. Anyway, there can still be an average of 40 mg of it in the cup of green tea (1); so why is it that people feel much better drinking tea?

Caffeine works in synergy with others

A key may lie in tea’s other key contents: polyphenols and theanine. Especially abundant in green tea, epigallocatechin 3-gallate (EGCG or EGC3G) is found to be the most potent tea polyphenols for anti-oxidative, anti-mutagenic and anti-pathogenic effects. Scientists isolating this substance from green tea for experiments discovered that it is often bonded with caffeine to form larger particles. Some found that the two substances working together would be much more effective in the said preventive functions, particularly in burning more calories and preventing cancer (3).

Liver Health

Caffeine intake protects the liver (4). It works better together with green tea catechin for synergic effectiveness. It has been found that the intake of catechins in its pure extract form does not show the same high effectiveness as in drinking green tea, with its caffeine content (5). This is one more reason tea drinking as a habit is far more helpful for your health than taking supplements.

Calm and Focused

While coffee keeps you awake and tense, tea helps to stay calm and focused. Theanine, another key salutary element unique in tea, plays an important role. It has been proven that the material effectively calms the person by working as a facilitator in signal transmission between nerve cells. This relaxing effect balances out the tenseness that may have brought about by caffeine. That is why while both coffee and tea help you to stay alert, tea has a very different and much more desirable effect.

Better bones

Some people would also be concerned of caffeine causing the loss of calcium in the bones. There have been findings that people with coffee habits have a tendency of bone problems in older age. Some scientists therefore hypothesize that all beverages with caffeine should be avoided. There are other studies that prove tea to be contributive to stronger bones, though. A study in Australia (6) involving 1,500 women between the age of 70 to 85 concluded that tea drinking helps preservation of hip bone structure in older women. In another word, prevention of osteosclerosis not uncommon in the post-menopause population. Similar studies in the Netherlands, UK, Turkey, Iran, Japan and China have all point to the beneficial effects of tea in preventing bone problems such as osteoporosis. The hypothesis that tea would cause bone weakening as would coffee, therefore, does not have a strong ground. The positive effects, however, are caused by EGCG and quercetin (a kind of flavonols) rather than by caffeine.

There are, however, cases of acquired osteosclerosis or fluorosis because of chronic exposure to fluoride in tea. Fluoride is typically higher in over-grown tealeaves. Over-growns are used by large scale farms to make low quality tea products, such as commercial grade tea bags, bottled drinks and instant mixes. Exceptionally large quantity of consumption of such products may lead to the named side effects.

Next> Caffeine: How Much is Safe?

footnotes

1. Survey of Caffeine Levels in Hot Beverages, Food Standards Agency, UK, August 2004

2. J Söhle et al, White Tea Extract Induces Lipolytic Activity and Inhibits Adipogenesis in Human Subcutaneous (Pre)-Adipocytes, Nutrition & Metabolism May 2009, doi:10.1186/1743-7075-6-20

3. C. Cabrera, R. Artacho, R. Giménez: Beneficial Effects of Green Tea—A Review. Journal of the American College of Nutrition, Vol. 25, No. 2, 79–99, 2006 / F.L. Chung, J. Schwartz, C.R. Herzog, & Y.M. Yang. Tea and cancer prevention: Studies in animals and humans. Journal of Nutrition, 133, 3268S–3274S, 2003

4. C. Ruhl, J Everhart: Coffee and Tea Consumption Are Associated With a Lower Incidence of Chronic Liver Disease in the United States, Gastroenterology 2005; 129:1928–1936

5. X. Jin et al, Green tea consumption and liver disease: a systematic review, Liver International 2008 Aug;28(7):990-6 / K Imai, K Nakachi: Cross sectional study of effects of drinking green tea on cardiovascular and liver diseases, BMJ (British Medical Journal) 1995;310:693

6. A. Devine, J.M. Hodgson, I.M. Dick, R.L. Prince: Tea drinking is associated with benefits on bone density in older women. American Journal of Clinical Nutrition, 86:1243–7, 2007