Although it was traditionally claimed that eating chocolate can make acne worse, this was dismissed as a myth based on a study published back in 1969. Funded by the US Chocolate Manufacturers Association, researchers investigated whether chocolate causes spots in 65 teenagers with mild to moderate acne. Volunteers were asked to eat an enriched chocolate bar providing ten times the amount of cocoa solids found in a typical 45g bar, or an identical-looking bar that contained no chocolate but did contain the same amount of vegetable fat and sugar. After eating one of the bars every day for four weeks, they had a 3-week rest, then switched over to eat the other type of bar, so they acted as their own controls.
When all the lesions on the left side of the face were counted, before and after each test period, no significant differences were noted between the two groups. Five healthy volunteers who did not have acne were then asked to eat two of the enriched chocolate bars every day, for a month, and no changes were found in the quality or quantity of their skin oils. These early researchers concluded that chocolate does not cause acne, and that remained the official line for the next 45 years.
Maybe chocolate does cause acne after all
Researchers now dispute these early findings and consider the results flawed because:
- Both males and females were included, and the results could have been affected by hormonal changes throughout the monthly cycle.
- Only one side of the face (the left) was assessed.
- Researchers only considered acne was worse if the total number of blackheads, papules and pustules increased by 30%.
- Only the total number of lesions – blackheads, papules and pustules – were counted. Someone could have started with 10 blackheads and 2 pustules, and finished with 2 blackheads and 10 pustules, for example, which would have been classed as no change from a total of 12 lesions, even though the acne was significantly more inflamed.
In real life, dermatologists and acne-prone chocolate lovers alike have noticed definite links between eating chocolate and a tendency to develop blackheads and pimples so, rather belatedly, more research was planned.
Does the sugar in chocolate make acne worse?
Other studies have found definite links between following a high glycemic diet and a worsening of acne symptoms. A trial was therefore designed to compare the effects of eating chocolate with eating jelly beans. If the sugar in chocolate makes acne worse, then the results should be the same when an equal amount of sugar was eaten in the form of jelly beans instead.
A lucky group of 54 college students were asked to eat either a 1.55 oz (43g) Hershey’s milk chocolate bar (around 11% cocoa solids) or 15 jelly beans (which provided the same sugar load) on two separate occasions. Their acne was then assessed by a dermatologist 48 hours after each sugar fest.
The results were surprisingly different. Eating the chocolate triggered significantly more acne lesions than eating the jelly beans. After eating the chocolate, participants developed an average of 4.8 more acne lesions within two days. After eating the jelly beans, they had around one spot fewer than before. This suggests that eating even a single bar of chocolate can make acne worse, but this isn’t linked with the sugar.
Does the milk in chocolate make acne worse?
If chocolate makes acne worse, but it’s not the sugar, perhaps it is the milk. Milk contains androgen hormones and growth factors, and a diet that includes a high intake of dairy products is associated with worsening acne.
The next logical step was to test how eating white chocolate (which contains milk, sugar and cocoa fat but no cocoa solids) affects acne compared to eating 100% dark chocolate which contains cocoa solids and very little else. It is so bitter it is something of an acquired taste).
In this trial, 57 volunteers with mild-to-moderate acne were divided into three groups and asked to eat either 100g of white chocolate, 100g of 100% dark chocolate or no chocolate at all, every day, for 30 consecutive days. Their number of inflamed, non-inflamed and total lesions were counted at the beginning, after 2 weeks, and at the end of the 30 days.
In the white chocolate group, the average number of inflamed and non-inflamed lesions increased from 45.9 at the start of the study to a total of 54.6 spots. In the dark chocolate group, and in the control groups no significant differences occurred. This study suggests that eating white chocolate is bad for acne while eating pure 100% dark chocolate does not have an effect.
If the studies stopped there, I could have told you to switch from eating white or milk chocolate to eating good quality dark chocolate and everyone would have been happy. But as always, it’s not as simple as that. Other studies have found that eating dark chocolate can make acne significantly worse in some people.
Does dark chocolate make acne worse?
A disheartening study asked 25 acne-prone males to eat 25g of 99% dark chocolate every day for 4 weeks. Their acne was assessed weekly, and they completed food frequency questionnaires to exclude other dietary influences. In an ideal world, their acne should have improved due to all the beneficial anti-inflammatory polyphenols present in the dark chocolate. No such luck.
Within 2 weeks, a statistically significant increase in the number of comedones (blackheads and whiteheads) and in the number of inflammatory papules was detected. This increase remained statistically significant at 4 weeks and the researchers concluded that eating dark chocolate can exacerbate acne in men with acne-prone skin.
This was shown in another study where 14 men with mild acne were asked to take capsules filled with either unsweetened 100% cocoa, or hydrolyzed gelatin powder, or a combination of the two.
Each volunteer swallowed the same number of capsules in a one-time ‘binge’ but didn’t know if they were getting six ounces of cocoa powder, six ounces of gelatin, or doses in between (one to five ounces of cocoa powder topped up to six ounces with gelatin).
Their skin was photographed before the capsule binge, then again after 4 days and at 7 days. A statistically significant increase in the number of acne lesions (comedones, papules, pustules or nodules) was seen by day 4 and persisted until day 7. There was a definite dose response so that those taking the most cocoa developed more acne lesions than those taking the lowest dose. The average total number of lesions increased from 3.9 to 10.5 by day 4 with most still present by day 7. The number of comedones increased more than the number of inflammatory lesions.
Although this study involved small numbers of people, it does seem to provide compelling evidence that the cocoa solids present in dark chocolate can exacerbate the skin of acne-prone males. Dark chocolate is likely to affect females, too, but studies tend not to use female volunteers because of the confounding effects of hormone changes throughout the menstrual cycle.
There is a note of caution however, in that gelatin powder isn’t a true inactive placebo. Gelatin contains collagen has definite beneficial effects on the skin, improving texture and reducing wrinkles with long-term use.
Collagen supplements are widely used to improve acne and many people find them effective when taken as an oral supplement, or when applied to the skin as a collagen mask.
Do the polyphenols in chocolate make acne worse?
If we accept that eating dark chocolate might make acne worse, and it’s not the milk, sugar or fat that’s to blame, the only thing left is the antioxidant polyphenols.
These have a powerful anti-inflammatory effect against conditions such as coronary heart disease and are also beneficial for the brain. It makes sense that the anti-inflammatory effect of dark chocolate should improve acne, too, but their immune-boosting effects might be counter-productive by triggering an increased white cell response.
This was tested in seven volunteers who donated blood samples after a week of eating no chocolate, and again after eating 50g chocolate (30% cocoa solids) every day for four days. Immune cells extracted from these blood samples were then exposed to skin bacteria associated with acne (Propionibacterium acnes and Staphylococcus aureus) to assess their response.
Priming immune cells with chocolate polyphenols was found to ramp up the action of white blood cells against P. acnes bacteria, and to suppress their level of attack against S. aureus in the laboratory. If the same effects happen in the skin, then an increased response to P. acnes might make inflammation worse. At the same time, the damping down of inflammatory responses against S. aureus could promote superinfection with the development of pustules and delayed healing of spots.
So does eating chocolate make acne worse?
The majority of evidence points to chocolate making acne worse in some people. Everyone is different, and not all will be affected.
If you are not prone to acne, and have blemish-free skin, there is no cause for concern. Select good quality dark chocolate (at least 70% cocoa solids) and enjoy the health benefits. Medicine can taste good – so much so that a cacao powder even has an approved EU health claim that it ‘helps maintain the elasticity of blood vessels, which contributes to normal blood flow.’
If you are prone to acne, however, you may have to rethink your relationship with chocolate. Even one small bar, eaten on one occasions, could well set the scene for a nice outbreak of spots.
You probably know from personal experience whether or not eating the white, milk or dark stuff affects your level of whiteheads, blackheads or pimples. Answer the poll below – does eating chocolate make your acne worse?
Click here to read more about the link between diet and acne.