

Low Fat Diet and Sunscreen: a Recipe for Disaster - bayareaguy
http://people.csail.mit.edu/seneff/sunscreen_lowfat_autism.html

======
mechanical_fish
Ignoring the window dressing about the health risks of extreme low-fat diets
(which are real, and there's plenty of better writeups on them) this is an
article about Vitamin D. And the question you have to ask when you see an
article like this is: What's the groundwork-to-hysteria ratio? I see plenty of
hysteria here, but no data. There's one cited reference to the scientific
literature... but it's on a different subject.

There's nothing wrong with _hypothesizing_ that (a) modern medical practices
are leading to deficiencies in Vitamin D among certain populations and (b)
Vitamin D deficiency is linked to autism. But the responsible next step is to
get some good data, or at least link to some. It's not to write stuff like
this:

 _Since the 1970's, our country has witnessed a 3000% increase in the sales of
sunscreen products, alongside a 30% increase in deaths from melanoma[17].
Isn't it time to admit that sunscreen is not working?_

This is a telling paragraph. It tells me that the author is prone to making
mistakes straight out of Darrell Huff's _How to Lie With Statistics_ : Clock A
strikes midnight a few seconds before clock B; isn't it time to admit that A
caused B to strike?

Autism seems to be one of those issues that really inspires the quack
epidemiologist. When you combine it with the opportunity to lecture new
mothers -- our culture's favorite vice -- the temptation becomes irresistable.
But it's worth remembering that actual epidemiology is really hard. Diagnosing
autism without bias is hard. Randomly sampling the population for autism is
even harder. Even something relatively simple, like measuring Vitamin D levels
in the blood, is tedious and expensive and difficult to do without bias. But
just because anecdotes and handwaving are much easier doesn't make them more
believable.

~~~
kingkongrevenge
> How to Lie With Statistics

There is no fallacy in the statement you've focused on. I'm a bit confused.
Sunscreen is sold and used to prevent cancer. There's no evidence it has, and
sound reasons to suggest sunscreen has contributed to cancer. That's all it's
saying.

> Diagnosing autism without bias is hard.

Are you suggesting the autism epidemic is a product of better diagnosis? If
so, where are all the autistic 50 year olds?

~~~
mechanical_fish
Do I have to spell it out?

The observation is that sunscreen sales and melanoma rates are correlated.
That's probably true, but it doesn't tell us anything about causation, one way
or the other. Perhaps sunscreen is ineffective against melanoma. Or perhaps
melanoma rates are rising because sunscreen use causes melanoma. Or perhaps
sunscreen sales are rising _because_ melanoma rates are rising. (As someone
who has just watched a close relative die of metastatic melanoma, I assure you
that the experience really inspires you to wear sunscreen and go to the
dermatologist. Every time I get a pimple, I have to fight the desire to visit
the emergency room.)

Perhaps sunscreen sales and melanoma rate would be completely unrelated, if
they weren't both driven by an external cause. Perhaps they're both caused by
population increases in the Sun Belt, or by other demographic changes.

Perhaps sunscreen is highly effective against melanoma, but there are still
lots of older patients who got all their sun in the 1940s, 50s, and 60s before
sunscreen was invented, and those patients are still getting melanoma at large
rates. Or perhaps sunscreen is completely ineffective, but we won't know until
the people who used it as kids reach their sixties. Or perhaps sunscreen
_causes_ melanoma... but it takes more than fifty years to do so.

Perhaps sunscreen causes autism! I guess that's what this article is trying to
suggest.

As you can see, pulling hypotheses out of one's ass is easy to do, and it's
fun for the whole family. It's also uninformative. _Scientific studies_ would
be informative. I'm sure there are lots and lots and lots of published studies
which address hypotheses like these. It's a pity that the article didn't cite
any of those studies.

~~~
jcl
It seems likely, at least, that sunscreens are ineffective against melanoma.
Via a link on the Slip-Slop-Slap Wikipedia page
(<http://en.wikipedia.org/wiki/Slip-Slop-Slap>):

"While few epidemiologic studies have examined the relationship of sunscreen
use and skin cancer, two studies suggest that sunscreens may not be effective
in preventing skin cancer. A large case-control study showed higher risks of
melanoma in men who used sunscreens, and a large prospective study showed a
higher incidence of basal cell carcinoma in women who used sunscreens. The
excess risks in the latter study persisted after multiple adjustment for
differences in skin type and time spent outdoors."

\-- "Could Sunscreens Increase Melanoma Risk?"
<http://www.ajph.org/cgi/reprint/82/4/614>

~~~
mechanical_fish
Hooray, links to data!

This is from 1992 and earlier, though. One wonders if there has been any more
progress in recent years.

And here is where I get to rant about my _own_ pet peeve: Why should I be
surprised that so few people know how to properly cite scientific literature?
That literature is locked behind paywalls! I'm not going to even bother using
PubMed on this, and it's only partly because I don't care. It's mostly
because, even if I turn up a definitive set of review papers in _Nature_ on
this very topic, I won't be able to read them without paying $15 each, or
whatever.

~~~
jcl
I'm not sure if you are referring to the article I quoted or to its
references... but the page that I linked to let me download the article
directly for free, despite a sidebar link that purportedly also allows you to
purchase the article. (I was surprised, too.)

I, too, wonder if there aren't more recent studies. The two studies cited were
from 1985 and 1990, though; if that's the most they could come up with in
1992, it sounds like the area is sparsely researched.

~~~
mechanical_fish
The references, of course. It's hard to operate without them. Particularly
when you're outside of your own field, and can't just name the various schools
of thought -- and the major authors and manuscripts associated with them --
off the top of your head.

------
jmatt
Assuming this woman doesn't own a chain of tanning salons as her side gig -
it's a good read. An interesting alternative to the current opinions on
vitamin D, Autism and low-fat diets.

As I read it, I quickly categorized it as an interesting persuasive essay
citing supporting facts. I have no problem reading papers like this and
gaining what I can from them. There is a place for persuasive essays and a
place for research papers. As long as the author is not trying to misrepresent
- no problems.

I read up on the author a bit and she seems to be closer to an expect on these
issues than a vast majority of op-ed diet and autism write-ups that I've seen.
Plus she's got an undergrad biophysics degree to boot.

<http://people.csail.mit.edu/seneff/>

------
StrawberryFrog
The author reads like a kook, but the good thing is that they put forward a
testable hypothesis (that vitamin D deficiency causes autism, or at least
increases the risk of it) so it should be either confirmed or disproved by
further studies.

~~~
kingkongrevenge
It's already researched to hell. This has been clear from the evidence for a
long time now. It just contradicts the dogma.

~~~
StrawberryFrog
See the para near the end: "However, I will concede that thus far there is no
definitive study that would leave no doubt that this hypothesis is correct.
This, more than anything else, is what's needed to really convince people to
dramatically change their practices"

------
hugh
Rules to live by:

1\. If someone feels the need to point out, at the end of an essay, that they
have a PhD, they're probably a kook.

2\. That goes doubly for anyone who feels the need to tell you which
prestigious institution their PhD is from.

------
KirinDave
This article is interesting, but I cannot take it seriously until the sources
begin to link to more supporting medical literature. Nearly half of the links
are to a website with a domain specifically selling this message. I clicked
around this site and didn't find _any_ citations.

I'm sorry, but the format of this site trips off my whackjob detector and no
one should be willing to take random medical advice without at least the
appearance of support from the medical literature.

This is doubly true when it comes to subjects of fertility or diet.

------
danteembermage
Some economists are causing tons of trouble by using economic-style research
design to show autism rates are linked with cable television and the rain.
Certainly tv watchers in rainy city washington are going to get less sunlight,
so that adds more credence to her argument.

Their study:

[http://www.johnson.cornell.edu/faculty/profiles/Waldman/AUTI...](http://www.johnson.cornell.edu/faculty/profiles/Waldman/AUTISM-
WALDMAN-NICHOLSON-ADILOV.pdf)

~~~
jbert
> economic-style research design

If you sample 100 uncorrelated variables looking for significance at 95%
confidence, you should find about 5 which are significant.

Data mining to produce hypotheses is fraught with danger. You should declare
your hypothesis and then go to the data, otherwise your confidence measurement
is bogus.

------
mhb
Doubling of vitamin D for children is urged:
[http://www.nytimes.com/2008/10/13/health/policy/13vitamind.h...](http://www.nytimes.com/2008/10/13/health/policy/13vitamind.html?scp=1&sq=vitamin%20d&st=cse)

------
josefresco
That trip to Mexico at the 'all you can eat' resort my wife and I took when
she was 6 months pregnant suddenly looks like brilliant vacation planning.

~~~
kingkongrevenge
It's not a question of eating a lot. Gorging on pasta when pregnant will just
produce a type I diabetic child. The issue is animal/fish fat consumption.
Women and children need quite a bit of it.

~~~
coglethorpe
"Gorging on pasta when pregnant will just produce a type I diabetic child."

ORLY?

Seriously, is there study that show a low-fat/type I diabetes connection?

~~~
kingkongrevenge
The issue is in utero insulin exposure.

<http://tinyurl.com/447xh5>

When mom eats french fries and rice the insulin spikes permanently screw up
the kid's endocrine system, leaving a propensity to obesity if not diabetes.

~~~
fallentimes
Are the obesity rates in countries with diets high in rice consumption (e.g.
Japan) especially high? Or is it usually offset by something (so in Japan's
case: fish consumption)?

~~~
delackner
Living in Tokyo, an obese person really sticks out. You just almost never see
them. You do see some fat teenagers though, since they are abandoning the
traditional diet.

Japan is in love with fat in all its forms (fatty marbled beef, fatty tuna,
fatty pork) and there is almost no culture of sun-screen usage, but they also
are much better at producing melanin than europeans, making for pretty
effective natural protection.

They also have one of (if not the) largest populations of centenarians on
earth.

------
boredguy8
Cargo Cult Science

<http://calteches.library.caltech.edu/51/02/CargoCult.pdf>

~~~
WilliamLP
True, this article immediately fails Sagan's bullshit detector. Claiming you
understand _any_ cause of autism is an extraordinary claim if there ever was
one.

------
kingkongrevenge
In conclusion: never trust a doctor without verifying things on your own.
Doctors are no smarter than the financial professionals who have obviously got
things disastrously wrong lately.

~~~
StrawberryFrog
Well, I disagree with that generalisation. A good doctor makes decisions based
on evidence (symptoms of the patient, proven effect of the treatment) as well
as experience as a doctor.

When "verifying things on your own" you run into all kinds of unfounded and
delusional ravings on the internet. Doctors may err on the side of
conventional wisdom, but that's not a call to disregard them and err on any
nonsense that you come aross.

~~~
fallentimes
Then why do most doctors reject evidence based medicine?

~~~
emmett
I presume you're talking about "evidence based medicine" the right wing
medical reform movement, not all medicine based on evidence. Because while
many doctors reject that movement, few seem to reject using evidence to pick
treatment regimes.

~~~
fallentimes
Is it really right wing? Why? I've just read multiple articles about how slow
Dr's are to adopt it even though, empirically, it is more effective. I figured
they rejected it for the same reason people always reject things: "that's the
way we've always done it".

Now granted, those articles could have been biased, but I had no idea there
was any sort of left wing vs right wing thing going on. Stupid politrix.

The entire movement reminded me of Moneyball by Michael Lewis.

~~~
emmett
There are, of course, a few doctors who reject the very idea that mere
scientific evidence should be able to tell them what to do. But in general,
most doctors want to provide the best care they can for their patients, and
that includes scientific evidence.

However, it's extremely common for doctors to prescribe medicine off-label,
before the full level three trials have completed for that use (which can take
a decade). There is often compelling evidence a medicine is effective (in the
Bayesian sense) far before there is official "Evidence" which counts for
"Evidence Based Medicine".

The very fact that it's called "Evidence Based Medicine" should set off alarm
bells. Being against it sounds like being against science in medicine, which
would just be stupid. In fact, it's code for "restrict public care facilities
from being able to offer a full range of medical benefits to conserve money".

~~~
fallentimes
Thanks for the information. I seriously thought it was much more like the
Moneyball situation where it was just a bunch of old schoolers not accepting
reality & empirical evidence and instead relying on standard practices and
conventional wisdom.

P.S. We just fully implemented Twisted at TicketStumbler :) (I heard you guys
use it, and love it, at Justin.TV).

~~~
emmett
I'm sure there's some of that too :).

Twisted really is awesome; we've been super happy with it. A little sad they
wouldn't take our memcache get_multi patch (they said we hadn't written enough
tests for it).

