Drinking tea may be a natural way to
improve your health. Evidences continues to mount in favour
of the consumption of tea benefiting the heart, protecting
from some cancers, stop bad breath, fight diseases and even
ensure weight loss.
Teas, both green and black, have potent anti-cancer effects
against a wide range of cancers, many scientists keep saying.
For instance, a study led by the US Department of Agriculture
on the health benefits of tea linked this to its polyphenol
content. Green tea contains between 30 and 40 per cent of water-extractable
polyphenols and the black tea (green tea that has been oxidized
by fermentation) about three to 10 per cent of these substances.
The four primary polyphenols found in fresh tea leaves are
epigallocatechin gallate (EGCG), epigallocatechin, epicatachin
and gallate, and epicatachin.
Mendel Friedman and his co-workers
from Universities in South Korea investigated tea’s
ability to induce cell death in human cancer and normal cells
using either its water or alcoholic extract and found it
inhibits tumour growth, though at different levels dictated
by the concentration.
This latest study corroborate an earlier one that found that
drinking at least one cup of tea a day could cut the risk of
cancer in the gallbladder and bile ducts by about 40 per cent
in a population-based study carried out in China.
The researchers, led by Ann Hsing from the US National Cancer
Institute, assessed the demographic, medical and dietary histories
of 627 people with bile tract cancers (cases), 1037 people
with bile stones and 959 randomly selected healthy controls.
The sample population was based in Shanghai, China, where the
incidence of these types of cancers is reported to have increased
in recent years.
Specifically, women tea drinker had associated reduced risks
of gallbladder cancer, bile duct cancer, and bile stones of
44, 35 and 37 per cent respectively. For men, no significant
association was observed for tea drinkers and the relative
risk of these conditions.
More evidence of tea’s brain health benefits is similarly
supporting both green and black tea been able to protect against
age-related diseases like Alzheimer’s as well as improve
memory.
The research, published in the
European Journal of Neuroscience, was the first to show beneficial
effect of both green and black tea on cell cultures treated
with amyloid proteins (amyloid proteins are associate with
the onset of Alzheimer’s
disease) just as another team at the University of Newcastle
said that tea, and particularly green tea, helps improve memory
in patients with Alzheimer’s disease.
The study’s lead researcher, Dr. Ed Okello, said: “Although
there is no cure for Alzheimer’s, tea could potentially
be another weapon in the armoury which is used to treat this
disease and slow down its development” in the journal,
Phytotherapy Research. Dr. Okello added that the findings suggested
tea could boost the memory of everyday drinkers too.
Tea has long been believed to possess blood pressure lowering
effects in popular Chinese medicine. The scientists from the
National Cheng Kung University in Taiwan, Taiwan, that examined
the effect of tea drinking on the risk of newly diagnosed hypertension
in 1507 subjects aged 20 or older, who did not have a hypertensive
history when the study started even confirmed this.
Almost 40 per cent of the subjects
were defined by the scientists as “habitual” tea
drinkers, meaning they consumed at least 120 millilitres
of green tea or oolong tea everyday for at least a year.
The more tea people drank, the lower their risk of high blood
pressure, the authors said in the Archives of Internal Medicine.
For non-habitual tea drinkers, the risk of developing hypertension
decreased by 46 per cent in comparison with those that drank
120 to 599ml per day. This was further reduced by 65 per cent
in those who drank 600ml daily or more.
This evidence that tea drinkers
may actually suffer less from hypertension, the Japanese
study also suggested may be linked to black tea’s action
on blood vessels. The drink dilates the vessels allowing
faster blood flow.
Research published in the October issue of the journal,nutrition,
showed that five servings of black tea per day reduced LDL
cholesterol, the bad cholesterol, by 11.1 per cent and total
cholesterol by 6.5 per cent in those with mildly high cholesterol
level. This definitely is substantiating another study in Saudi
Arabia that found that people who drank more than six cups
of black tea daily lowered their risk of coronary heart disease
by more than half, compared to those who were not regular tea
drinkers.
Meanwhile, compounds found in
tea is said to also stop the growth of bacterial that cause
bad breath, according to researchers at the University of
Illinois at Chicago. Polyphenols, chemical components of
tea, prevent both the growth of bacterial responsible for
bad breath and the bacteria’s production of malodorous
compounds the research said.
In the laboratory study, Wu and
Zhu incubated tea polyphenols with three species of bacteria
associated with bad breath for 48 hours. At concentrations
ranging from 16 to 250 microgramme per millilitre, the polyphenols
inhibited growth of oral bacterial. At even lower concentrations – from
2.5 to 25 microgrammes per millilitre-the polyphenols hindered
the enzyme that catalyses the formation of hydrogen sulphide,
cutting its production by 30 per cent, they reported.
Research finding in her laboratory had also shown that black
tea suppresses the growth of bacterial in dental plaque and
even the act of rinsing the mouth with black tea can help to
reduce plague formation and the production of acids that cause
tooth decay.
Bones are not left out either. Long-term consumption of black,
green or oolong tea can help strengthen bones researchers from
the National Cheng Kung University Hospital in Tainan, Taiwan
have reasons to believe.
People who drank an average of nearly two cups a day of these
three tea varieties over a six-year period were shown to have
a significant higher bone density than people who did not drink
tea, or who drank it in smaller quantities.
Writing is the Archive of Internal Medicine; the researchers
said they discovered that people who said they had consumed
tea regular for more than 10 years had the highest overall
bone-mineral density.
Even those that want to protect
themselves from the effect of smoking, researchers also suggested
should take tea regularly. Based on the findings in the October’s
issue of the Journals of Nutrition, the researchers at the
Arizona College of Public Health, University of Arizona and
Arizona Cancer Centre in Tuscon studied the effect of tea
on 143 heavy smokers for four months and from this concluded
that it may also protect against damages from smoking.
Similarly, tea drinker stands
to have their immune system primed to fight infection and
chronic diseases because its antioxidant’s content
helps the body destroy free radicals.
In an experiment, people who drank five to six small cups
of black tea daily for two weeks were better able to fight
off bacterial infections, a study said in an edition of the
Proceedings of the National Academy of Science.
So when next you are thirsty, try taking tea rather than water,
it is healthier. Water is essentially replacing fluid, but
tea replaces fluids and contains antioxidants, so an added
advantage.
There is no need to worry about
tea dehydrating the body either. This is an old wives’ tale
that is not backed up by any science. Whether it is the green
or black tea, just keep drinking. |