"Does Chocolate Cause Acne?"
Acne affects nearly 1 in 10 people in the world,
making it perhaps the eighth most prevalent disease worldwide.
What’s the role of nutrition?
Well, go back a century and dermatology textbooks
were recommending various dietary restrictions.
For example, recommending those with acne
avoid foods like pork, sausage, cheese,
pickles, pastries, sweets, cocoa, and chocolate.
Yeah, but old-timey medicine was full of crackpot theories.
Dr. Kellogg, for example, blamed acne on masturbation.
Nothing a few corn flakes couldn’t fix though...
Population studies have found associations
between acne and the consumption of foods
like dairy, sweets, and chocolate,
but you don’t know if it’s cause and effect...
until you put it to the test.
There have been high quality reports,
like the Harvard Nurse’s study,
that looked at nearly 50,000 women
and found a link between adolescent milk drinking and acne,
particularly skim milk,
something that’s been found for teenage boys as well.
They thought it might be the hormones
in milk that were responsible,
but it could also be the milk protein, whey,
of which they add extra to skim milk
to make it less watery,
which may play a role directly
in acne formation or as hormonal carriers.
That would explain cases like this:
where whey protein powders were implicated
in precipitating acne flares in teens
who had acne that just didn’t seem to want to go away
until they stopped the whey.
It doesn’t appear to just be a protein effect,
since soy protein supplements, for example,
did not seem to cause the same problem.
But, for dairy, in terms of interventional studies,
all we have are these kinds of case series.
If you do a systematic review of acne and nutrition,
you get results like this for dairy:
out of the 20 or so papers on acne and dairy out there,
about three-quarters suggest adverse effects,
and the remainder report no effect,
with no studies suggesting a beneficial effect
of dairy on acne;
so, you could look at this and conclude
a dairy-free diet is worth a try.
But, this is based on low-grade evidence,
level C and D evidence,
where C is like the population studies,
and D is kind of like those series of case reports.
What we want ideally are randomized
interventional studies, level A and B evidence,
which we don’t have for dairy,
but we do have for chocolate.
When it comes to acne,
no food is more universally condemned than chocolate.
So, if you’re the Chocolate Manufacturers Association,
how are you going to design a study
to make your product not look so bad?
Well, you can always use the old drug company trick
of pitting your product against
something even worse;
and so, they fed people
chocolate bars versus fake chocolate bars
made out of a partially hydrogenated vegetable oil:
trans fats.
So, make it have more sugar,
throw in some milk protein,
and make it 28% pure trans fat laden,
Crisco-like vegetable shortening.
And surprise, surprise
there were just as many pimples
on the fake chocolate bars,
allowing them to conclude that eating high amounts
of chocolate is A-OK
when it comes to acne.
And, the medical community fell for it.
“Have we been guilty of
taking candy away from babies?”
“Too many patients harbor the delusion
that their health can somehow be mysteriously harmed
by something in their diet.”
That original study “finding that chocolate consumption
supposedly does not exacerbate acne
has continued to remain virtually unchallenged
for decades and continues to be cited”
even in recent reviews.
For example, this pediatrics journal.
Years ago, it was demonstrated
that chocolate consumption had no effect on acne.
“This serves as a cautionary example
of how ‘research-based evidence’
should be vigorously scrutinized
prior to being incorporated into clinical practice.”
Just because something is published in the
Journal of the American Medical Association
doesn’t necessarily mean it’s a good study,
especially when industry interests are involved.
Maybe we should be telling acne patients
to try cutting down on not only the sweets and the dairy
but also the trans fats
found in partially hydrogenated vegetable oils,
but we can’t be unequivocal
in our advice to acne sufferers
on foods to include or exclude until...
they’re put to the test in well-designed randomized
controlled clinical trials.
But there simply weren’t any
such trials on acne, until...
NOW, which we’ll cover, next.