Myths and rumors circulate in a very similar way

to the way that microbes spread.

They can be contagious in that one person hears something,

they pass it on to another person and another,

and suddenly a rumor becomes really well-established,

and I think we've always had this problem

but with the Internet and social media,

just the scale, the scope,

and the speed of it is really amped up.

I'm Dr. Seema Yasmin and I'm a doctor,

a Professor at Stanford School of Medicine, and Director

of the Stanford Center for Health Communication,

and I'm going to debunk some illness and disease myths.

[light instrumental music]

People kind of want to know like exactly

how much water should I be drinking,

but there isn't that magic number.

I think this myth has been circulating for a long time,

and somehow eight glasses

of an eight-ounce glass specifically is what's circulated.

It depends on your body size

and how active you are at a given time.

There is no reason to eat your placenta.

I do hear from people that they want to eat their placenta

because monkeys or other wild animals do it,

but the reason that those animals are doing it is

because they don't want to attract predators.

There is no reason for a human to eat a placenta.

Your heart does not skip a beat when you sneeze.

I think a lot of us grow up hearing things about sneezing,

that your eyes close and your heart skips a beat,

and you're like a dead for a millisecond or something.

Yeah, clearly not true.

Adults have fewer bones than babies,

and that's actually true,

because babies are born with some bones

that fuse to become a bigger bone.

There is a phenomenon known as the July effect,

which wonders and asks this question

that if you have massive turnover,

new residents starting, new faculty starting around July,

then isn't that a more dangerous time to be in a hospital?

And there have been 300 studies looking into this,

and it turns out that it depends

on what kind of hospital it is,

who you're being looked after,

like how experienced they are,

but also what kind of illness you are

and how seriously sick you are.

The take home from this is that if you're sick in July

you still need to go to a hospital,

and by and large you're in good hands.

[light instrumental music]

So your body makes toxins

as it metabolizes different things,

but the thing is your body also flushes those things out.

You don't need to be doing anything

or taking anything to cleanse yourself.

Flat Tummy Tea is, most of them are not good for you.

They kind of go under this umbrella of,

oh well it's natural or it's herbal,

but those herbs are no joke.

Sometimes Flat Tummy Teas contain senna,

which yes it's a herb, but it's also a laxative.

So if you wanna crap the weight out,

I mean all you're doing is emptying your bowels

and becoming dehydrated.

Your body does have waste products in it.

That's why you pee and that's why you poop,

and even when you breathe you are exhaling carbon dioxide,

which is a waste product,

but your body is perfectly primed to do that,

to get rid of what you don't need.

People do ask about colonics.

You do not need them.

You do not need to put coffee up your butt.

You don't need to be shoving liquids up there

to get anything out,

unless of course you have constipation

and the doctor prescribes an enema,

but if you're healthy and functioning fine

then you don't need to do a colonic.

[light instrumental music]

People are making billions

of dollars off dietary supplements

that many of us don't need, and that includes vitamins.

If you are eating a well-balanced diet,

you're getting the vitamins that you need

and you don't need to be popping a pill to stay healthy.

You need to take a vitamin

if your healthcare provider tells you you have a deficiency

and you need to top up and take a pill

or take a liquid that boosts your level of that vitamin.

[light instrumental music]

MSG is not addictive, it's not unsafe,

and the thing that I was fascinated with

when I was writing this was that those myths

that you've heard about MSG, that it's addictive,

that it's really bad for you,

are all tied to racism and the fact

that it was Chinese people owning Chinese restaurants

that were using it, and that's how it got labeled

as something that was dirty and toxic.

In moderation it's no worse for you than regular salt.

[light instrumental music]

People have asked me if genetically modified food is safe,

whether they should pay more for non-GMO food,

pay more for organic food, but GMO food is safe,

and the definition of organic honestly can be so broad

and vague and different from one place to another

that most doctors will say,

Just eat a healthy, balanced, varied diet,

and you don't necessarily need

to pay more for organic for most foods.

I do get asked about artificial sweeteners a lot

because a lot of my friends like to chug diet sodas.

The thing to bear in mind here is that some

of the studies are not that robust,

so you might have seen headlines saying,

Diet sodas cause Alzheimer's disease,

or, Diet soda causes stroke,

and they're not necessarily true, and the thing that I worry

about then is will people ditch the diet soda

and just start drinking sugary soda

when we know that those are linked

to diabetes and other illnesses?

Artificial sweeteners, the kind that you find in diet sodas,

do not cause Alzheimer's disease, stroke, and cancer.

You may have seen headlines that say that,

but I think that they are misconstruing

what the scientific studies are really showing.

There have been studies showing some harmful effects

of artificial sweeteners in rats,

but then you have to take that with a large grain of salt

to say that while just because

it did something in a rodent's body,

will that translate into happening in a human's body?

But if you wanna be really careful,

you can just drink water, the great message.

You are a little bit taller first thing in the morning,

probably no more than a centimeter though,

and that's just because gravity compresses your joints

during the course of the day.

It's also why when astronauts come back

to earth after a space mission

they are a little bit taller than when they left earth.

There are studies showing that bad teeth,

especially bad gums, can lead to heart disease

and make you more susceptible,

and that's because of the bacteria

that causes gum disease can circulate

through the blood and cause illness elsewhere.

It's certainly something

that makes us look at the patient holistically,

so it's important to get your blood pressure checked

and it's important to eat well,

but it's also really important

to get good dental hygiene and get routine checkups

to make sure your gums are as healthy as everything else.

There are some studies

that are quite exciting that show that aspirin,

which we already recommend for a number of things,

might lower the risk of cancer,

but there's still more research being done

and there aren't a ton of medical organizations saying,

Hey, everyone should take an aspirin pill everyday

to prevent cancer.

What we're learning is that

it's certain types of cancer in particular,

and that there might be something about aspirin

that prevents metastatic cancer,

that prevents cancer cells from moving around the body,

but even in that case it might be that the aspirin works

for that only in some people and not in every one.

I get so many questions about aspirin

because it feels like every year

we discover a new use for it.

It is an incredible, incredible drug,

but the jury's still out on aspirin preventing cancer.

Please do not stop taking an antibiotic the moment

you feel better if you still have more

to complete the course.

It's really important that if you have 10 days of pills

that you feel better on day four or day three even,

you still have to finish that course of antibiotics

so that the bug does not become resistant to the medicine.

Antibiotics cannot help with a cold.

Most colds, most sore throats are caused by viruses,

and antibiotics will not do anything to those.

Antibiotics fight bacteria very specifically,

so if you have a virus circulating in your blood,

taking an antibiotic will not help.

It's been circulating for ages

that you should starve a fever and feed a cold.

You just need to eat well and stay hydrated

when you're not well.

It is dangerous to starve yourself,

like that's a thing that we know that's proven,

so if you have a fever stay hydrated and eat well.

The flu shot can definitely not cause the flu.

The flu shot might make you achy,

but for the vast majority of us,

getting the flu shot is a fantastic idea.

You will not get the flu from it and it will keep you safe.

I think we all grew up hearing that

you should never go outside in the cold

when your hair is wet,

or like make sure you bundle up,

and our mothers loved doing that to us.

During cold times is when

there are more cold bugs circulating anyway,

and also there is some research that shows

that cold weather might impact the immune system,

but I don't know if it's that robust.

I think it's still a good idea though to wrap up very warm.

You do not lose more heat from your head

than anywhere else on your body.

You can tell a little bit about what's making somebody sick

from looking at the color of their sputum,

which is the disgusting thing that you cough up.

For example if it's very clear,

that's less likely to be an infection usually.

If it's green or yellow,

more likely to be a bacterial or viral infection.

I think doctors are good at assessing the color of sputum.

I think people are coughing up out of their lungs.

If you are emptying your nose into a tissue,

probably looking at the color to try and figure out

exactly what bacteria is causing it,

that's not gonna be something you can assess.

People wonder if their ears stop growing

when the rest of them stops growing,

and actually your ears carry on growing forever.

So the current guidelines in the US

about men who have sex with men can only donate blood

if they've been celibate for 12 months,

which is ludicrous and stupid and unscientific.

It wasn't until 2015,

30 years after we had a test for HIV AIDS,

that gay men and bisexual men were told,

Yes you can donate blood, but there was a major caveat,

and that caveat was that men who have sex with men

could only donate blood

if they had been celibate for 12 months.

Vaccines do not cause autism.

I may get that tattooed on my face at some point in 2020.

I'm kind of being sarcastic here,

but if a patient was to ask me that

I will take their concerns really seriously

and not be dismissive

'cause I wanna know why they think that,

and I wanna make sure

that I reassure them that vaccines are safe,

and what they cause is a long life and good health.

The best way to disinfect your hands is to wash them

very well with water and soap and then to rub them clean.

Hand sanitizer's good if you're in a bind,

but is nowhere near as good

as washing your hands with soap and water.

I get asked a lot of questions about alcohol gel,

hand sanitizer, and like disinfectant wipes,

and they are really useful, they do disinfect surfaces,

but nothing is equivalent to disinfecting your hands

as washing them with soap and water.

It's true that many patients cared for

by a female doctor have better health outcomes.

There've been a number of studies

that show that patients do better, they live longer,

they're less likely to be readmitted to the hospital,

if they're cared for by a doctor who is a woman,

and at the same time,

women doctors face lots of discrimination

and get paid less than our male counterparts.

It's hard to avoid misinformation sometimes.

There is so much false health news circulating,

and sometimes you can just feel overwhelmed

even with the correct information.

I think the important thing to do is to talk

to a healthcare provider that you feel like you can trust,

who has an open mind, and someone that gives you the time

and space to talk about what's really concerning you.