- Grandma has been saying for an eternity
that drinking hot liquids is not a good idea
and now some medical research may just be on her side.
Let's talk about it on this week's Wednesday Checkup.
Bee-woop!
(vibrant music)
Last week they were headlines popping up
all across the Media Television, YouTube, Twitter.
I was being flooded by messages of people telling me
that hot tea can increase your rate of cancer.
Being someone who's a huge fan of green tea, I was confused.
What I'm gonna do in this video is translate to you
what the research was that they conducted,
what the findings were and how they apply to you
or is this a case of media sensationalism.
I feel like we should always get our biases
out into the open before we speak.
I've always been taught even as a child
by my father who's a physician
that drinking hot liquids is very bad.
If I drink soup that was too hot, my dad would say bad idea.
If I drink tea that was hot, he would say bad idea.
This study took 50,000 individuals
living in the Northeast part of Iran, aged 40 to 75,
interviewed them, conducted a bunch of surveys
and followed them for a period of 10 years.
What's positive about this?
Well, it's a great sample size, 50,000 individuals
solid age distribution and a period
of 10 years is also a very good sample size.
You're gonna get a lot of quality info
from a lot of people over a lot of human life years.
The next thing that popped into my head was
how did they measure the temperature of the tea
that people were drinking over 10 years?
What they did was, they would bring in the people
that are gonna be participating in the study,
they would brew two cups of tea,
one for the interviewer, one for the interviewee,
they would have a thermometer inside the tea
wait for the tea to drop to about 167 degrees Fahrenheit,
ask the participant to take a sip
and ask them if that's the normal
temperature of the tea that they drink.
If not, they would let it drop by five degrees Celsius
and continue doing that process
until they reach a temperature
that they feel they can drink the tea comfortably
and that it matches their daily habits.
Now we have to say this method is not perfect,
'cause over a period of 10 years,
maybe their preferences can change
but this is an objective way of measuring it,
as opposed to just asking the question,
do you prefer your team mild, cold, very hot, hot?
There's a lot of room for interpretation there.
If you put a thermometer in and you get
a person's response as to whether
or not this is the type of tea they drink,
that is way more objective than just handing them a survey.
Let's jump in and look at the results
of the study right off the bat.
They found that the participants who drink 700 MLS,
which is about three cupfuls of tea a day
at a temperature of 140 degrees Fahrenheit
or higher actually increased their risk
of developing esophageal cancer by 90%.
For those of you who don't know,
esophageal cancer is cancer of the esophagus,
the tube that connects the throat to the stomach.
These findings did not surprise the researchers
and other doctors alike because we've been saying
for a long time that drinking very
hot beverages is not ideal for our bodies.
The theories behind that is that the thermal damage
or just the burn that can actually
happen inside our esophagus
can lead to more inflammation,
which leads to DNA damage leading to cancer.
Another explanation for this could be
that the thermal or burning damage
actually inhibits esophagus from protecting itself
thereby making it susceptible to carcinogens
that appear within our bodies every single day.
But, but, but, but and this is a very important but.
I have to make it known right now,
they did not establish a cause and effect relationship here,
they did not prove that drinking hot tea
directly will cause esophageal cancer
or directly will have an impact on this esophageal cancer.
They did a study observing people's behavior
and try to link that behavior to outcomes.
This is called a correlation or an association.
So it's not as strong as a cause and effect principle
because there could be confounding factors at play.
Those who drink hot tea also tended
to be older males, live in rural areas, be poor
so could that have contributed
to their increased risk of cancer?
It's possible, that's why a correlation study
is never as powerful as a cause and effect study.
Now, although there is no cause and effect relationship,
this correlation should still bring
some useful knowledge to us
because we have to think about risks versus benefits.
There is no benefit and there's just never been even
discussed the benefit in drinking liquids,
whether it be soup, tea or coffee
at temperatures above 140 degrees Fahrenheit.
So if I can tell you to let your tea cool down below 140
and that will possibly maybe even likely,
depending on the strength of this correlation,
decrease your likelihood of developing cancer,
it seems like that should be the wise thing to do.
If you disagree with me jump into
the comments section, we'll duke it out.
I know the temperature that these
things are brewed at, let's talk about it.
Green tea, 175 degrees Fahrenheit,
black tea, 210 degrees Fahrenheit,
herbal tea, 212 degrees Fahrenheit,
coffee, around 200 degrees Fahrenheit.
All of those are above that 140 degree Fahrenheit margin
and if you drink them too quickly after brewing,
not only are you gonna possibly burn your mouth
but you could also be increasing your risk
of esophageal cancer, amongst others,.
I also have a little bit of concern
when it comes to some products
that are currently out in the market.
I know there's a lot of these mugs
that can keep your coffee or tea automatically warm,
because there are electric devices
that you can charge and so forth
but the temperature ranges at which
they can keep your tea hot to
can get past 140 degrees Fahrenheit.
So maybe these companies should take
a look at this research and say,
well, we're gonna aim to keep your tea warm and hot,
but not above 140 degrees Fahrenheit
'cause there's some research linking
this to increased risk of cancer.
My final takeaway on this study is exactly as I said before,
there's no risk for letting your tea or coffee cool
just a little bit before drinking it.
Use some common sense, don't burn your mouth
and understand that if you're burning your mouth
you're also definitely burning your esophagus.
Don't increase your risk of cancer unnecessarily,
let it cool, be smart, but also understand
that this isn't perfect research
and that there's still more research to be done
to understand what types of tea,
what types of coffee at what exact temperatures,
how does it change between different
sexes or different populations
and that's what's exciting about medicine,
the fact that we will always be doing more research
and we will be understanding our bodies more and more.
This is where I get to have fun.
And if you wanna know the right way to drink green tea
and all the health benefits it may have to offer
click here for my green tea video
and as always, stay happy and healthy.
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