When a study in her lab showed that mate tea drinkers
had experienced a significant increase in the activity
of an enzyme that promotes HDL (good) cholesterol while
lowering LDL (bad) cholesterol, University of Illinois
scientist Elvira de Mejia headed for Argentina where mate
tea has been grown and taken medicinally for centuries.
She returned with a five-year agreement with La Universidad
Nacional de Misiones to cooperate in the study of 84 genotypes
of mate tea, both cultivated and wild, never-before-studied,
"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
"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
"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 ½ 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
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
Heck and de Mejia of the U of I and Teresita Menini and
Alejandro Gugliucci of Touro University co-authored the
study of the effect of mate tea on HDL cholesterol, which
appears in the September issue of Planta Medica. The study
was funded by the University of Illinois Research Board
and Touro University.