�Our studies show that some of the most important antioxidant enzymes
in the body are induced by this herbal tea,� said de Mejia of her
study in September�s Planta Medica.
�Because Argentina has the different mate varieties, we�ll be able to
do more comparisons and characterizations between the different
genotypes and the benefits of different growing conditions�whether in
sun (on a plantation) or in shade (under the rainforest canopy),� she
added.
Not only does de Mejia hope to identify the most nutritionally
beneficial genotypes of the herbal tea, she hopes that Argentine
experience with drying and processing mate will lead to improved
extraction of the tea�s bioactive compounds. �Food companies are very
interested in adding tea extracts to juices, soda, and even beer to
increase the nutritional value of their products,� she said.
In the cholesterol study, blood levels of the cardio-protective enzyme
paraoxonase-1 were measured before and after healthy volunteers
consumed either 0.5 liters of mate tea, milk, or coffee. Activity of
the enzyme increased an average of 10 percent for mate tea drinkers
compared to the other drinks.
�The tea used in the study was prepared at the same concentration used
in South America, although they usually drink 2 to 3 liters per day,�
said de Mejia.
In South America, mate is usually drunk from a dried gourd and
consumed through a metal straw. About 50 grams of dry leaves are
packed into the gourd and hot water is poured over them; this is
repeated many times, with as much as � to 1 liter of water. This
method of consumption allows tea drinkers to slowly extract the
antioxidants and polyphenols before they can be oxidized.
�To duplicate these results with mate teabags, you would need to use
four or five teabags instead of one. It�s a strong taste, but many
people say that coffee has a strong, bitter taste. This is more of a
grassy herbal taste. It may be an acquired taste, but I seem to have
acquired it,� said graduate student Caleb Heck who accompanied de
Mejia to Argentina.
Heck characterized the tea consumed in the cholesterol study in de
Mejia�s U of I labs and is now working with the tea brought back from
Argentina. He said that mate is high in xanthines (mainly caffeine),
and he has found 12 polyphenolic compounds at different concentrations,
depending on where the tea was grown. Polyphenols are thought to have
a protective effect against cancer and cardiovascular disease.
He is quickly becoming something of an authority on the subject, and
he and de Mejia have written a comprehensive review of mate tea,
including its chemistry, health implications, and the technological
considerations involved in its processing, that has been published in
November�s Journal of Food Science. The study was funded by the
University of Illinois Research Board.
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