Study Shows Chocolate Aggravates Immune Response Against Acne Bacteria

Recently published study found that eating chocolate increases the immune response against acne-causing bacteria. This could explain why chocolate seems to cause acne for some people.

I really don’t like this study. My family was just visiting from Finland and they brought some chocolate over, knowing how I like it. Most of it is still in the fridge, tempting me, and in my mind I’m imagining relaxing and savoring moments with a good book and chocolate. Then the %*#*$! Dutch researchers publish a study showing chocolate is bad for my acne! Could they not wait until I had finished the chocolate?? Some people just have no manners, lol.

Anyway, back to the point.

The researchers showed that exposure to chocolate primes human blood cells to having much stronger immune response against Propionibacterium acne (P. Acnes) or Staphylcoccus aureus bacteria.

The study had two parts. In the first part they took blood cells from volunteers with acne and grew them either in a growth medium or in chocolate. Then they added the two bacteria into the mix and measured how much inflammatory cytokines the cells produce. Cytokines are sort of signaling or communication molecules. The ones measured in this study act as sort of alarm signals for the immune system. They attract immune system killer cells into the area.

Here are the results from the first part:

Cytokine response in cells cultivated in chocolate flavonoids or normal growth medium

Source: Chocolate consumption modulates cytokine production in healthy individuals

As you can see, cells cultivated in chocolate medium showed much, much stronger immune response.

In the second part of the study they asked the volunteers to eat 50g of milk chocolate for 4 days. The researchers then collected blood cells from the volunteers and stimulated them with the two bacteria. Here are the results.

Effect of chocolate eating on cytokine response

Source: Chocolate consumption modulates cytokine production in healthy individuals

As expected, the results are not as clear cut as in the first part, but we still see a clear increase in some of the measured cytokines. Before refers to values before the 4 days chocolate diet and after, well, after the chocolate diet. The lines represent values for each study participant; there were only 7 in this very small study. As you can see, there’s always a lot of noise in measurements like these, but the figures b and e show a statistically significant difference from before and after.

It’s hard to know what to make of this yes, as this was such a small study. If the results hold up in larger studies, this could be one explanation for why chocolate causes acne.

Ugh, these results make me depressed. I guess that means I have to raid the fridge for some delicious chocolate.

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About Me

Hi, I am Acne Einstein(a.k.a. Seppo Puusa). I'm a bit of a science nerd who is also passionate about health. I enjoy digging through medical journals for acne treatment gems I can share here. You can read more about my journey through acne and how I eventually ended up creating this.

11 thoughts on “Study Shows Chocolate Aggravates Immune Response Against Acne Bacteria

  1. I don’t like this study either! However, after reading only your synopsis of the study I have a question. You mentioned that in the second part of the study they fed participants MILK chocolate. Did the first part of the study test MILK chocolate or DARK chocolate (without any milk added)? For me, this makes a huge difference. I have noticed that if I indulge in milk chocolate, I pay the price the next day but if I have dark chocolate (usually 80-90% cacao), I am fine. This goes along with my mostly dairy free diet, so I’ll let myself believe it’s the milk so I can still eat my dark chocolate and enjoy it too!

    • I only have access to the study abstract so I can’t say for sure, but based on the abstract it seems they only used chocolate flavonoids (the antioxidants in chocolate). Flavonoids are both in dark and milk chocolate, in fact dark chocolate has more of them than milk chocolate.

      In your case it’s probably not chocolate that causes acne but dairy products. Perhaps you have an allergic reaction to milk proteins.

  2. Aw, say it ain’t so, Seppo! I have recently gone vegan again, but I love dark chocolate. I have been enjoying 72% dark chocolate often, and put organic cocoa powder in my breakfast smoothies. I’ve only had a minor improvement in my skin so far. Perhaps this is why. 🙁

    I just read a few minutes ago about rubbing banana peels on your skin to help reduce inflammation and acne. I’m gonna give it a try. I keep the bananas on hand for my smoothies, anyway.

    • It ain’t so! To be honest, you shouldn’t stress too much over this study (in retrospect, maybe I should not have even written this post) because it’s very preliminary. It’s always hard to say what happens in humans based on test tube studies. So it’s possible this has no effect on humans. We just don’t know yet.

      I wouldn’t actually expect much improvements in acne from going vegan. Most foods that aggravate acne are vegan foods (fiber and FODMAPS can aggravate gut issues, sugar and high GI carbs aggravate hormonal acne, etc). So it’s possible, even likely, your lack of improvements has nothing to do with chocolate. I still use cocoa powder to make smoothies.

  3. Hey Seppo,

    These recent chocolate studies hit pretty close to home since dark chocolate is one my favorite foods! Really would like to get to the bottom of this one. I managed to track down the full text:

    https://worldcocoafoundation.org/wp-content/files_mf/1388082728Netea2013HumanNutritionCytokineAcne.pdf

    The chocolate used was 30% cocoa content milk chocolate (Milka brand). Here’s the ingredient list of the Milka chocolate used in the study:

    https://www.google.com/search?q=milka+chocolate&safe=off&espv=2&source=lnms&tbm=isch&sa=X&ei=HISHU_epEM62yATo1oLADg&ved=0CAcQ_AUoAg&biw=1600&bih=1220#q=milka+chocolate+ingredients+in+english&safe=off&tbm=isch&facrc=_&imgdii=_&imgrc=6w9X1oECOokGUM%253A%3Bf4TJCsfpzbS90M%3Bhttp%253A%252F%252Ftn.openfoodfacts.org%252Fimages%252Fproducts%252F762%252F230%252F002%252F6752%252Fingredients.6.400.jpg%3Bhttp%253A%252F%252Ftn.openfoodfacts.org%252Fmountaj%252F7622300026752%252Fmilka-chocolate-dessert%3B400%3B80

    Pretty bad, eh? I’m wondering if, for instance, the skim milk powder may have been responsible for the enhanced production of pro-inflammatory cytokines. Or perhaps just as Dr. Bob commented in your more recent chocolate article, just the stress of patients eating the chocolate for 7 days, believing it was going to make their acne worse? Bummer that there was no control in this study – I’m not sure how you even could do a control.

    • Good points, Devin. At this point it’s hard to say what this study means, if anything. What worries me is that while all the studies that link chocolate to acne are scientifically quite weak, they all point to the same conclusion. Just have to wait for more definitive studies to come out.

      The chocolate they used in the 2nd part of this study looks quite bad for acne. And it’s certainly possible that something other than cocoa caused the effect. In the 1st part of the study they used some flavonoid preparation. I assume it’s far more ‘pure’ than the milk chocolate used in the 2nd part.

  4. Hmm, yeah I’m not really sure how the OmniCoa flavonoid preparation compares to real-world chocolate. After reading the description of how it’s processed, I’m still not sure what’s removed from the chocolate – it’s possible that there are other inhibitors removed?

    https://www.natural-specialities.com/natural-specialities/PDF/Data-sheets/OmniCoa%2055%20-%20Datasheet%20v1.2.pdf

    Also, I just learned that chocolate is extremely high in phytic acid, which could impair digestion and increase gut permeability and worsen acne through the gut/brain/skin axis. Especially since my digestion doesn’t feel top-notch at the moment, it may be time for me to stop eating 1/2 a bar of 85% dark a day… 🙂

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