Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

about us





Bad breath from proteins? Green tea helps

The polyphenols in green tea can help solve a problem that many athletes on a protein-rich diet are familiar with: bad breath. A Japanese study on the subject, published in the Journal of Nutritional Science and Vitaminology, shows that substances in green tea such as EGCG [structure shown below] inhibit the production of sulphurous gases by micro-organisms in the mouth.

Bad breath from proteins? Green tea helps

Complete animal proteins contain the amino acids methionine and cysteine. These amino acids are also found in dead cell material in the mouth. Organisms that live in the mouth cavity - bacteria such as Streptococcus are well-known examples - use these amino acids to produce sulphurous gases like hydrogen sulphide [H2S] and methanethiol [CH3SH]. If you exhale large quantities of these gases chances are you have bad breath.

Hydrogen sulphide smells of rotten eggs, methanethiol smells like a marsh with lots of decaying organic material. If you eat a lot of animal protein, these gases are probably present in high concentrations in your breath. Especially products that leave a thin film of proteins behind in your mouth and throat can really mess up your breath - whey shakes for instance.

Substances such as EGCG probably inhibit the formation of sulphurous gases. EGCG is toxic to streptococci, and because the latter also cause cavities in your teeth, EGCG can also have a catabolic effect on your dentist's bill. Surely then it's logical that green tea would promote fresh breath?

To test the theory the researchers did a study on fifteen test subjects whose breath stank of rotten eggs and fetid swamps. They got the test subjects to brush their teeth, chew sugar-free chewing gum, suck peppermints, chew parsley seed - or keep a couple of teaspoons of green tea powder in their mouth for two minutes. The amount of polyphenols in the powder was about seven hundred milligrams, the equivalent of seven cups of green tea.

Afterwards the researchers measured the concentration of sulphurous gases in the test subjects' breath. The figure below illustrates the effect right after the treatment.

Bad breath from proteins? Green tea helps

Those who had used green tea powder had a considerably lower concentration of sulphurous gas in their breath. The effect is fairly short-lived however.

The worst smelling gas in the breath is the marsh gas methanethiol. Fortunately green tea has a longer lasting effect on this foul-smelling gas in the breath it still works after an hour. See the table below.

Bad breath from proteins? Green tea helps

The effect of green tea powder on hydrogen sulphide [rotten eggs] lasts much less long, as you can see below.

Bad breath from proteins? Green tea helps

Proteins neutralise the polyphenols in green tea. The effect of green tea on the breath is therefore stronger the less food remains there are in your mouth.

Bad breath is not only a social problem, but it is not healthy for your mouth. Sulphurous gases inhibit the growth of connective tissue.

J Nutr Sci Vitaminol (Tokyo). 2008 Feb;54(1):89-94.

Meta-study reveals best way to lose weight by green tea supplements 09.05.2020
Green tea has a slightly anabolic effect on strength athletes 14.01.2013
Drink three cups of tea a day and add five years to your life 11.09.2009


Green tea healthier and more effective on empty stomach Green tea inhibits cortisol synthesis Green tea improves cholesterol

Green tea healthier and more effective on empty stomach
If you drink green tea or take capsules containing green-tea extract in the hope that they'll make you healthier, fitter or slimmer, then do so on an empty stomach.

Green tea inhibits cortisol synthesis
Green tea is a cortisol inhibitor, and it may well be a very effective one.

Green tea improves cholesterol
When a meta-study shows that green tea also improves cholesterol levels, we are not a bit surprised.