Proportion
of Tannin
Class of Number of Per cent. Per cent. Per cent. corresponding
Teas. Analyses. Extract. Alkaloid. Tannin. to 2·8
per cent.
Alkaloid.
Indian Teas 18 26·11 2·84 7·43 7·32
Ceylon Teas 12 26·04 2·68 7·85 8·20
China Teas 13 22·12 2·40 6·08 7·09
Thus the Ceylon teas under the conditions of experiment part with
slightly more tannin than the India or China teas. It will be noticed
that the proportional tannin figures for the India and China teas are
not very different, although some of the individual China teas give out
less tannin than any of the India or Ceylon samples. It is possible
that the China average is rendered rather high by an undue proportion
of green tea which of course shows excess of tannin. The question will
naturally be asked whether as a nation we do not drink too much tea,
and there is a very simple means of solving the problem. As shown
in table A the average consumption per head per annum in the United
Kingdom is 6·1 pounds, or 117 grains of tea per diem. The average
percentage of alkaloid in tea, as consumed, I calculate to be 2·8 per
cent., and of tannin 7·5 per cent. This will mean that each person
will take a daily dose of 3·28 grains of alkaloid and 8·8 grains of
tannin. According to the last Census 3,716,708 out of 32,527,843, or
10 per cent. of the population of England and Wales, are under five
years of age; these might almost be neglected as far as tea-drinking
is concerned, so that we must add one-tenth to the average daily dose
of the alkaloid and tannin, which will come to 3·6 grains of alkaloid,
and 9·7 grains of tannin. The dose of caffeine according to the British
Pharmacopœia is from one to five grains and of tannin from two to five
grains. And hence on an average each person in the United Kingdom is
constantly day by day consuming half as much alkaloid, and nearly as
much tannin as would be permissible to be taken occasionally as a drug.
Therefore I have no hesitation whatever in saying that we drink far
too much tea, and the question has been raised in Ireland whether the
excessive drinking of strongly infused tea has not had something to do
with the increasing prevalence of insanity in that country. Thus in
the Forty-third Annual Report of the Inspectors of Lunatics, Ireland
(1894), the Inspectors dwell on the ill effects of decocted or over
infused tea on persons who make it a staple article of dietary, thus
leading to the production of dyspepsia, which in its turn tends to
states of mental depression highly favourable to the production of the
various forms of neurotic disturbance.
Thus Dr. William Graham of the Armagh District Asylum refers to the
recent changes of dietary having an unquestioned influence on the
increasing prevalence of insanity. He refers to the use of Indian
tea as a beverage between meals. “The tea,” he says, “is stewed, not
infused, as a consequence the use of increased amount of nervine food
leads to a peculiar form of dyspepsia, which in its turn leads to
a general debility of the nervous system. This change is therefore
to be considered as a factor in the increase of insanity.” Dr. G.
W. Hatchell, the Resident Medical Superintendent of the Castlebar
District Asylum, stated that “amongst the female inmates, I believe
many cases of insanity may be attributable to the frequent consumption
of decoction of tea, taken generally without food and for lengthened
periods.”
Again Dr. Thomas Drapes of the Enniscorthy Asylum, said “there is
not much evidence of the excessive use of this beverage (tea) being
directly provocative of insanity, but I think there is very little
doubt that its too liberal use excites or aggravates a predisposition
to neurotic disorders, including insanity, making the nervous
system more vulnerable in regard to such maladies, by the increased
excitability of the nervous system which tea undoubtedly produces.
A neurotic organisation may also be transmitted to their progeny by
parents who drink tea to excess.”
Lastly, Dr. E. E. Moore of the Letterkenny Asylum, said “As to the
consumption of tea, it seems to be enormous and increasing rapidly
all over the country. I am informed that it is taken by young and
old alike, and even by babes in the cradle. It is drunk as often as
it can be got, at every meal and between meals, often six times a
day, and especially by females and usually without milk, and often
without food. I may safely say that it is never taken as an infusion,
but is generally stewed for hours, the old leaves being left in the
teapot and fresh added as required. In some places I am told the way
the tea is made is by putting the leaves down in a saucepan of cold
water, and then boiling it until the decoction is black enough to be
palateable.... I can speak from practical experience of the terrible
effects of this system of tea drinking both among the sane and insane.
It gives rise to a severe form of chronic dyspepsia, and if persisted
in to dyspepsia of an incurable and painful form. The result of all
this is that the health of the people all through the county is
deteriorating more than most people imagine. In fact the people are
starving themselves on tea, and the weaker they become the more they
rush to the teapot for the fillip the draught therefrom may give
them for the moment. This tea-drinking is becoming a curse, and the
people are developing a craving for tea, just as great as that which a
drunkard has for alcohol, or a drug-taker for his own particular drug.
There is no manner of doubt but that the condition of bodily health
affects the mental health of every man, woman and child, and if the
starved stomach becomes a prey to chronic dyspepsia the chances are
very great that the mind will, before long, be materially affected
especially where there is a predisposition to insanity of an hereditary
type.” With these important testimonies from responsible officials, it
is difficult to resist the conclusion that the abuse of tea drinking
has acted as a factor in the increased prevalence of insanity.
As a general conclusion from my investigations I have no doubt that
in the first place we drink too much tea; this is shewn by a simple
calculation from the average annual amount imported for consumption.
Of course children of tender years should obviously be given no strong
stimulants (such as tea or coffee) and adults would be acting wisely
to very much limit the amount taken. With regard to the best method
of preparation it should be infused, (neither stewed or decocted) and
certainly for no longer period than five minutes, and a good plan is to
pour the tea off at the end of this time into another vessel so as to
save further exhaustion from the leaves. In reference to the variety of
tea best to use, although it is not certain that the average of China
teas contains less tannin than Indian teas, there is no doubt that
individual samples of China tea can be procured comparatively free from
this deleterious substance.
With a view of discovering the constituent parts of the tea popularly
consumed, I procured samples from each of the four leading Companies,
which probably amongst them, supply nine-tenths of the tea drunk in
London Restaurants. The infusion was made in exactly the same way as
described above and the analyses came out as follows:--