Bad Science
HW4
Re-Stating the Correlation
Researchers find a correlation between eating
bacon and low sperm count.
“Researchers found a correlation between
eating bacon and low sperm count. Therefore,
processed meat causes lower sperm count.”
More Causes
“Bacon causes a low sperm count because it
makes you fat, and that messes with the
hormones that regulate sperm development.
‘Alternatively’ processed meat (including bacon)
makes you fat, and this leads to low sperm
count.”
Parts as Causes
“Eating a bacon sandwich causes low sperm
count, because bacon is on a bacon sandwich
and bacon causes low sperm count.”
Eggs and Arteries
According to the article
“Egg Yolks almost as bad
as smoking,”
Dr. David Spence found
that “people who eat egg
yolks regularly have about
2/3 as much plaque
buildup as smokers.”
Eggs and Bacon
Eggs are often served with
unhealthy meals– omelets
with bacon and cheese,
cheeseburgers, fried rice,
greasy Korean soup…
Maybe it’s the things we
eat with eggs that cause
the plaque build up.
X causes A causes B
http://www.youtube.com/watch?v=68f2VqQY6z
0
“Abusive parents caused me to eat bacon, and
bacon causes lower sperm count. So my abusive
parents caused my low sperm count.”
HW5
Hypothetical
Imagine that science shows that some
treatment that is important to you is no better
than a placebo, and only works because people
believe it does—it’s only the placebo effect.
Imagine that the science is really good and not
flawed or biased or poorly conducted.
Defenses of Placebos
When presented with this question, people
produce a wide range of defenses of placebos–
reasons why we should still undergo certain
treatments, even if all the scientific evidence
said they work only through the placebo effect.
Common Defenses
Sometimes they accept that treatments were
placebos, but argued that that was OK:
1. Sometimes there are no other treatments.
2. If it works, it doesn’t matter how.
3. There are no side-effects, so taking a placebo
can be better than taking “real” medicine.
4. The placebo effect is a mental effect. But
sometimes the problem is mental too.
Traditional Chinese Medicine
In the case of Traditional Chinese Medicine, I
have heard that if science-based medical trials
(experiments) had results that said TCM was
only a placebo, there are other, non-sciencebased reasons for believing that TCM is real
medicine, and really works (not only through the
placebo effect).
“Western” vs. “Science-based”
I often hear TCM contrasted with “Western”
medicine. I don’t like to talk that way, I think it
confuses the issues.
Hong Kong Museum of Science
Qi Meridians
The Endocrine System
From Wikipedia
“In 1110, a Chinese medical text specified the use of
gypsum… as well as saponin from the beans of
Gleditschia sinensis to extract hormones from urine, a
process of using natural soaps which was not discovered
elsewhere until the use of digitonin by Adolf Windaus
(1876–1959) in 1909. In modern medicine, the extraction
of these hormones from urine is a standard practice, yet
centuries before this the Chinese had used it to treat
hypogonadism, impotence, spermatorrhea,
dysmenorrhea, leukorrhea, and even stimulating the
growth of beards (since they knew that castration
resulted in the loss of ability to grow a beard).”
Participation
“Dear Michael,
I know of one Chinese medical researcher who
does science based medicine. He/ she recently
did an experiment that showed…”
“Western” vs. “Science-based”
There is lots of non-science-based Western
medicine. Homeopathy, electroconvulsive
therapy, chiropractic, faith healing, naturopathy,
quack therapies for cancer…
Acupuncture as SBM
Additionally, there is no reason to think that
some TCM might become science-based
medicine in time. For example, some studies
have suggested promising effects for
acupuncture for some ailments. There are also
suggestions about plausible scientific
mechanisms that would explain how
acupuncture worked. If all that turns out– then
acupuncture will be science-based.
Project 523 and Malaria
For example there’s lots of
evidence that the Chinese
herb, qing hao 青蒿素
(artemisia) is useful in
curing malaria. (Mao’s
army tested 5,000 TCM
remedies for malaria, and
this was the only one that
worked. But it worked!)
Tiger Eyes One of the 4,999 Cures That
Did Not Work
Science-based Medicine
The difference between science-based medicine
(SBM) and non-SBM is that
1. SBM has evidential support in the form of
statistically significant RCTs
– or–
2. SBM has scientifically plausible mechanisms
that explain how it works.
Defenses of TCM
Common defenses of TCM I’ve encountered are:
1. It has a long history of many thousand years.
2. It’s holistic and flexible, treating the person,
not the symptoms.
3. It’s herbal or natural rather than chemical.
4. There are Chinese explanations for why it
works.
Defenses of TCM
More defenses:
5. TCM has spiritual effects beyond the physical
ones.
6. TCM gets taught in schools, and published in
journals– even in the West! (It is recognized by
authorities.)
7. It’s culturally important to use it.
PLACEBO MEDICINE
1. Sometimes There are No Other
Treatments
There’s no cure for the common cold.
The common cold is a virus that mutates very
rapidly.
Because it is a virus, antibiotic medications can’t
kill it, and because it mutates so rapidly,
vaccines can’t prevent it.
Zinc Lozenges
Some things actually do make you feel better–
chicken soup, surprisingly, has some medical
evidence backing it up. I eat it when I’m sick.
But I also buy zinc lozenges. I know they’re no
better than placebo lozenges– but that doesn’t
mean they aren’t better than nothing. Placebo
lozenges do cause improvement!
2. If it works, it doesn’t matter how
A common defense of “placebo medicine”
(medicine that was no better than a placebo) is
that it didn’t matter whether the treatment
caused the improvement or our beliefs about
the treatment caused the improvement—
The improvement is all that matters!
Nocebos
MSG is not harmful, but people who think it
harms them often suffer.
Wind farms are not harmful, but people who
live near them often suffer.
The Point
Something is wrong with the argument “if it
works, it doesn’t matter how it works” for
placebos.
The same argument could be given for nocebos:
“if it hurts, it doesn’t matter how it hurts: so
stop using MSG, and get rid of those wind
farms!”
3. There are No Side Effects
“The placebo effect is real
medicine, because it
triggers the body’s healing
system. One could argue
that this is the best
medicine, in fact, since: a.
drugs do not trigger the
healing system and b. the
placebo effect has no side
effects.” Deepak Chopra
Bullshit!
As to Chopra’s first claim, it’s bullshit.
Placebo’s don’t “trigger the healing system”–
they don’t do anything. That’s part of the
definition of ‘placebo’.
All real treatment has the same positive effect
as placebos and a lot more. The real stuff.
Can Placebos Have Side Effects?
As we’ve just seen, there are side effects even to
sugar pills: nocebo effects.
But let’s suppose we’re considering a case
where people believe that treatment X will help
them, and X performs no better than a sugar pill
in double-blind randomized placebo-controlled
trials. Can X still have side effects?
Yes!
Remember that a lot of evidence suggests SSRI’s
(selective serotonin reuptake inhibitors, a kind
of antidepressant drug) work no better at curing
depression than placebos.
This does not mean they do other things no
better than placebos. They are very good at
making you unable to eat, sleep, or have sex.
Harmful “Natural” Ingredients
Pure sugar pills (or saltwater injections) can’t
harm you any more than your beliefs can (which
can be significantly).
But invasive treatments or treatments with
pharmacologically active ingredients can harm
you, even if they are only as good as a placebo
at helping you.
Cancer in Taiwan
Taiwan has the highest per-capita incidence of
UUC (upper urinary tract cancer) of anywhere in
the world.
Plants of the genera Ephedra and Asarum
produce the toxic chemical aristolochic acid
which causes UUC.
TCM herbal remedies contain lots of these
plants, and tests have shown they contain
aristolochic acid as well.
Kidney Failure in Belgium
In a case report in “Nature” in 2011, a “slimming
clinic” in Belgium where women were taking
Chinese herbal remedies led to more than 100
women suffering kidney failure and many of
them later developing cancer…
From aristolochic acid, the same thing making
Taiwan #1 in UUC!
Other Harmful Side-Effects
Here’s a bottle of Saiga
Antelope Horn Powder.
The Saiga Antelope is
critically endangered, so
the fact that people take
these pills is currently
harming endangered
species.
Opportunity Costs
Sometimes “side-effects” are worth it. For
example, if the disease will kill you unless you
suffer through a painful debilitating treatment, it
may be worth it to undergo the treatment– at
least that way you’ll be alive!
Chemotherapy
Lots of cancer is treatable, and if detected early
enough, almost (but never quite) 100% curable.
For example, some kinds of lymphoma can be
cured in otherwise healthy patients with
chemotherapy and radiation therapy.
These treatments are not pleasant, and cause a
lot of suffering. But the alternative is death:
herbal teas don’t help.
4. Sometimes the Disease is Mental
One common defense of placebos is that
sometimes, the symptoms were entirely mental:
pain, unhappiness, stress, nervousness,
irritability– or things that these psychological
states can cause: ulcers, high heart-rate,
pimples, low sex drive, etc.
Expectations
If the symptoms are mental, then one might
suspect that a “purely mental” cure would work.
The placebo effect works by manipulating your
expectations. So maybe the placebo is the best
cure for certain illnesses.
Nocebo and Placebo
To some extent, this is true: people are sick
because they believe they should be (nocebo
effect) and they are cured by undergoing a
treatment that they believe should work
(placebo effect).
Chronic Fatigue Syndrome
But just because a condition is “psychological” does
not mean that it can be cured by the placebo effect.
For example, Chronic Fatigue Syndrome (CFS) is
thought by many to be an illness with purely
psychological causes. People try lots of treatments
for CFS, but none of them work. This is proof that
not all psycholgical illnesses can be cured with a
placebo.
Medicalizing Problems
Additionally, giving people pills or shots or magic
incantations or whatever for psychological
illnesses can “medicalize” those illnesses.
For example, if you give women a pill for sexual
problems, then even if it works only as a
placebo, they may conclude that their problems
were chemical in nature, rather than
psychological, a problem with relationships.
Traditional Chinese Medicine
I don’t pretend to know a lot about TCM. I know
very little.
I don’t want to argue here against TCM. This
class is “Logic and Critical Thinking” not
“Traditional Chinese Medicine.”
Hypothetical
But it’s the hypothetical that’s important to me:
imagine that science-based medicine concludes
that some treatment in TCM is no better than a
placebo…
Should we stop using that treatment? If TCM is
better than a placebo, we don’t have to answer
this question. But what if it isn’t…?
Not a Doctor
I’m not a (medical) doctor, and my job isn’t to teach
you medicine, and I can’t teach you medicine.
My goal is to make you think about medicine (and
other things) critically.
What are rational ways to respond to arguments–
for example, arguments that certain treatments are
no better than a placebo?
1. Long History
“Traditional Chinese Medicine works– how can
it not? It’s been around for 2,000 years. The
basic ideas are set forth in ‘The Yellow
Emperor’s Inner Cannon’, published around 100
BCE. If it didn’t work wouldn’t someone have
noticed in the past 2000 years?”
Astrology
Sometimes things don’t work, and they survive.
For example, almost every Western newspaper
contains a horoscope, a prediction of how your
day (week) will go, based on your Zodiac sign.
I’m told this happens in Chinese newspapers
too.
Astrology
In Western astrology, your exact date of birth
determines your horoscope. On that date,
certain constellations (clusters of stars) were in
certain positions in the sky, and the sun, moon,
and planets were in other positions relative to
those constellations.
Theoretically, this predicts your entire life!
No Evidence
Astrology doesn’t work, however.
If you give ordinary people random horoscopes,
their judgments about whether those
horoscopes apply are random.
If you give astrologers descriptions of people,
their judgments about which astrological sign
they have are random.
Age No Proof of Truth
Astrology is 5,000 years old.
Every Westerner knows his/her astrological sign,
and most Western newspapers contain
horoscopes.
All the evidence says it’s fake.
How?
The Forer effect is the observation that people
are highly inclined to believe that a description
is true of them, and highly accurate if (a) they
believe it is constructed from highly detailed
information about them and (b) it is vague or
general enough to apply to almost anyone.
Forer Effect
“You have a great need for other people to like and
admire you. You have a tendency to be critical of
yourself. You have a great deal of unused capacity
which you have not turned to your advantage.
While you have some personality weaknesses, you
are generally able to compensate for them. Your
sexual adjustment has presented problems for you.
Disciplined and self-controlled outside, you tend to
be worrisome and insecure inside. At times you
have serious doubts as to whether you have made
the right decision or done the right thing…
Forer Effect
…You prefer a certain amount of change and variety
and become dissatisfied when hemmed in by
restrictions and limitations. You pride yourself as an
independent thinker and do not accept others'
statements without satisfactory proof. You have
found it unwise to be too frank in revealing yourself
to others. At times you are extroverted, affable,
sociable, while at other times you are introverted,
wary, reserved. Some of your aspirations tend to be
pretty unrealistic. Security is one of your major
goals in life.”
Forer Effect
On a scale of 0 to 5, the average accuracy rating
for this prompt was 4.26, after subjects were
told it was a person-specific personality analysis.
In reality, the same prompt was given to all the
subjects.
My Horoscope
On horoscope.com today (Th) my reading was:
“You feel emotionally strong, even though certain
people may be getting in the way of your plans. You
can accomplish a great deal. You're only responsible
for yourself. You feel a drive to work harder than
usual. Even though you may be working very hard,
your general mindset is good. You should enjoy
your day regardless of the circumstances”
Chinese Horoscope
http://chinese.horoscope.com/astrology/freechinese-horoscope-dog.html
Old = Right?
Sure, this doesn’t mean that all old things are
still around due to the Forer Effect.
They could be here for good reasons, or on
account of confirmation bias, or cultural inertia,
or whatever.
But just because something is old, doesn’t make
it right!
Mao Created Chinese Medicine?
“Even though I believe we
should promote Chinese
medicine, I personally do
not believe in it. I don’t
take Chinese medicine.”
--Mao, according to Li
Zhisui, his personal
physician.
2. Holistic & Flexible
One charge against science-based medicine is
that it “treats the symptoms, not the causes”,
“treats the disease, not the person”, “is
inflexible, and applies the same treatment to
everyone”….
Alternative, non-science-based therapies are
often touted as avoiding these pitfalls.
I Don’t Know about TCM…
I can’t claim to know much about TCM
diagnoses and treatments.
English Wikipedia says: “In TCM, a disease has
two aspects: ‘bìng’ and ‘zhèng’… most of the
disease entitites (病, pinyin: bìng) listed by TCM
constitute mere symptoms… [证] are ultimately
defined by their symptoms and ‘signs’ (i.e., for
example, pulse and tongue findings).”
Homeopathy and “Holism”
That might be wrong… again, I’m not the one to
ask.
But similar arguments are made by Homeopaths
against science-based medicine, even though
Homeopathy is based entirely on symptoms. The
“Law of Similars” says that like cures like, if X
causes the symptoms you are experiencing, then
X can cure your disease.
Science-based Holism
Finally, remember why I like calling it “sciencebased medicine” instead of Western medicine.
It’s not about where it’s from, it’s about whether
science supports it.
Lots of ‘holistic’ and preventative treatments are
science-based: having a clean water supply,
vaccinating your children, eating healthy,
exercising, avoiding smoking and drinking…
3. Natural instead of Chemical
A common defense of ineffectual treatments
against science-based medicine is that they are
“natural” or “herbal” and not “chemical”.
This criticism isn’t very credible…
The Naturalistic Fallacy
• “I shouldn’t use painkillers during childbirth,
it’s not natural.”
• “GMO’s (genetically modified organisms) are
bad for your health, because they’re not
natural.”
• “Carbon Dioxide is Natural. It is not harmful. It
is part of earth’s life cycle. And yet we are
being told we have to reduce this natural
substance.” [Michelle Bachmann]
Responses to the Fallacy:
1. Everything is made out of chemicals.
2. “Natural” chemicals like arsenic and cyanide
are deadly.
3. Toxic “natural” chemicals regularly show up
in TCM– that’s why UUC rates are so high in
Taiwan.
4. “Non-natural” chemicals can be harmless and
life-saving. Antiretrovirals for AIDS make you
better.
4. Explained on Its Own Terms
One defense I hear often that TCM had its own
explanations, and didn’t need “Western”
explanations, or science-based ones.
For example, TCM might diagnose a certain
disease as being due to a Yin deficiency or an
imbalance of xuě 血.
Explanations vs. Evidence
We should distinguish between the explanations
and the evidence for those explanations. You
can have a nice-sounding explanation for
anything you want– but is it true?
TCM and AIDS
http://www.aworldofchinesemedicine.com/artic
les/chinese-medicine-hiv.htm
For example, you might think “HIV infection is
triggered by Toxic Heat, and initially attacks the
Spleen and Stomach Organ Systems.”
This of course does not suggest that you watch
out for needle sharing, blood transfusions, and
unprotected sex, as the germ theory suggests.
The Importance of Good Explanations
TCM is often used alongside science-based
antiretroviral therapy in the treatment of AIDS.
And I suppose it doesn’t harm, and it may help
with symptoms, depending on the treatment.
But believing the TCM explanations for AIDS will
kill you. The cause is a virus, a virus transmitted
in specific ways that we know about. Believing
something else puts you at risk for the disease.
Science is Common Sense
Science is not just one of many ways at getting
at the truth.
Science is the only way of getting at the truth.
It is just a rigorous way of applying the standards
that we all believe in and use every day.
Science is Common Sense
If you want to know whether eating a meatheavy diet or a vegetarian diet is more healthy,
you take two samples of people that are
representative of the population, feed one
group one diet and the other group the other
diet, and then measure which group does better.
That’s a Randomized Controlled Trial, RCT.
Science-based medicine is the collection of
treatments that do better in RCTs.
Science is Common Sense
Arguments like “it’s ancient” or “it worked for
me” or “it has this plausible-sounding
explanation” are open to bias.
Confirmation bias, bias from authority, the
regression fallacy, the placebo effect, the
clustering illusion…
If it really works, then it works in RCTs. And if it
works in RCTs, it’s science-based medicine.
5. Spiritual Healing
Another argument that some treatments are
worth continuing, even if they are no better
than a placebo in RCTs, is that they may be
better than a placebo in spiritual effects that are
not measurable to science.
Caricature: “This treatment makes your aura
brighter, even though it doesn’t make your
cough go away.”
How Do You Know?
Maybe. If it’s something that can’t be observed,
then I suppose there can’t be any scientific
evidence against it.
But there can’t be any scientific evidence for it
either. How do you know it actually makes your
aura brighter or whatever?
Aura Reading
If someone claims that
they can tell, but science
can’t… science can test
that!
Suppose science can’t
measure auras. We can
still test to see whether
other people can measure
auras.
Science Testing Non-science
For example, we can randomly give either the
treatment or a placebo to study participants.
Then we ask the aura reader– without telling
her which group each patient belongs to– to tell
us whose aura has gotten better.
If the treatment works, she should be better
than chance at telling who is a control or not.
6. Appeal to Authority
I also get this defense of TCM:
“Westerners teach TCM in medical schools.
Journals of medical research publish studies of
TCM. Lots of doctors use it, not just Chinese
ones. How can it be no better than a placebo?”
Let’s consider the question:
Why do medical schools, doctors, and medical
journals promote fake medicine like
homeopathy, reiki, naturopathy, etc.?
Why have so many Westerners turned to nonscience based medicine, when the Western
medical establishment is mostly science-based?
Certainty
In science, nothing is ever certain. Smoking
raises the probability that you’ll get cancer;
undergoing radiation therapy raises the
probability that you’ll beat cancer; you could get
cancer if you didn’t smoke; you can die from
cancer even if we do our best to treat you. Sorry,
but that’s life.
Certainty and Helplessness
People don’t like uncertainty. They don’t like
feeling that things are outside their control, that
their disease is caused by something they can’t
see, and can’t do anything about. Uncertainty
makes you feel helpless.
This is from a “Naturopathic
Oncologist”
When you’re frustrated with throwing up from the chemo
treatments, losing your hair, and feeling incredibly tired
all the time…maybe its time to look at a different option.
The advantages of using Alternative Medicine:
• guaranteed safe NO side effects – no harm done
• guaranteed immune boosters
• guaranteed easy to use – comfort of your own home,
no doc waits
• guaranteed more control of your health – can talk to
practitioners longer than 10 min
• guaranteed less invasive
What about Doctors?
And why do doctors latch on to non-sciencebased medicine?
That can be a long story, but consider the case
of antidepressants again. They (or at least SSRI’s)
don’t work any better than a placebo. Yet,
Western doctors prescribe them all the time.
The answer is more-or-less: fraud. There are lots
of ways to cheat in science. If you want your
study to show that antidepressants do better
than placebos, you can not double blind your
studies, or use improper randomization
techniques (this is obvious to real scientists,
though).
You can also:
• Only correct the baseline when it suits you.
• Ignore dropouts.
• Remove outliers when it suits you.
• Choose a statistical test that gets the best
results.
• Find your hypothesis in the data.
• Publish only positive findings.
7. Cultural Importance