Chocolate and acne: cocoa, sugar and the trials

For many years, as the authors of a 2016 trial put it, chocolate was thought to have no role in worsening acne. One of the first trials, published in 1969, found no effect. Since 2014, three newer trials have fed chocolate or pure cocoa to people with acne, and all three found more spots afterwards. This guide goes through each trial, what they can and cannot show, and how to decide whether chocolate matters for your own skin. It is part of Skinli's acne diet guide. The short summary is in does diet cause acne.

The four chocolate trials

Trial	Who	What they ate	Result
JAMA, 1969	65 people	Large amounts of chocolate	No effect on acne, as later summarized by other researchers
Journal of Clinical and Aesthetic Dermatology, 2014	14 men aged 18 to 35 with a history of acne; 13 finished	Capsules of unsweetened 100 percent cocoa, gelatin powder, or both	More spots on day 4 and day 7; more cocoa went with more new spots
International Journal of Dermatology, 2016	25 men with acne-prone skin, in Thailand	25 grams of 99 percent dark chocolate daily for 4 weeks	Higher acne scores and more blackheads, whiteheads and red bumps from week 2
Foods, 2024	92 people aged 18 to 45 in Poland, 88 of them women	50 grams of 85 percent dark chocolate daily for 4 weeks	Acne severity rose in both groups; 79 people worsened by one point or more

The 1969 study

The 1969 trial was published in JAMA. The authors of the 2024 Foods trial describe it as a study of 65 people, which found that eating large amounts of chocolate did not change oil production and did not worsen acne. They add that other scientists criticized it for how it counted spots and for not taking the dietary properties of chocolate into account. Skinli could not read the original 1969 paper, so this summary relies on the 2024 description.

The 2014 cocoa capsule trial

This trial was double-blind: neither the men nor the researchers knew who swallowed which capsules. Some capsules held unsweetened 100 percent cocoa, some held gelatin powder, and some held a mix. Spot counts rose on day 4 and day 7 compared with the start. Men who took more cocoa tended to get more new spots.

The capsules contained no sugar and no milk, which matters for the question of why chocolate might affect skin. A 2021 review in the American Journal of Clinical Dermatology points out two limits: the trial used one brand of cocoa, and it included no women.

The 2016 dark chocolate trial

Twenty-five men with acne-prone skin ate 25 grams of 99 percent dark chocolate every day for 4 weeks. Their acne was assessed every week. Acne scores and the numbers of blackheads, whiteheads and inflamed bumps rose by week 2 and stayed higher at week 4. There was no comparison group: each man was compared with his own skin at the start.

The 2024 crossover trial

This is the largest chocolate trial and the first with mostly women. All 92 people first followed an anti-inflammatory diet for a week. Then one group added 50 grams of 85 percent dark chocolate a day for 4 weeks while the other did not, and after that the groups swapped. In both groups, the acne severity score rose during the chocolate weeks, from 2.5 to 3.4 in one group and from 2.4 to 3.5 in the other, on a scale from 0 to 5. The authors write that it remains unclear which part of chocolate caused the change.

The authors list their own limits: people may not have followed the diets exactly, and other foods could have affected the results.

How the trials measured acne

Each trial counted acne in a different way, which makes them hard to compare directly:

• 2014 cocoa trial. Researchers counted every blackhead, whitehead, red bump, pus bump and deep lump, and took photos at the start, on day 4 and on day 7.
• 2016 dark chocolate trial. Researchers counted spots and used the Leeds revised acne score, a standard acne grading system, once a week for 4 weeks.
• 2024 crossover trial. Researchers used a 6-point scale from 0 (no spots) to 5 (severe acne). A rise of one point means the acne moved up one grade.

In the 2024 trial, 65 people rose by one grade, 13 by two grades and 1 by three grades. The smaller trials reported rising spot counts. Each trial lasted 4 weeks or less, so none shows what happens to acne over months of eating chocolate.

What was in the chocolate

The 2024 trial authors looked at each ingredient of the chocolate they used. They considered cocoa butter and sugar the ingredients most likely to worsen acne. They rated the other ingredients, vanilla extract and soy lecithin, as neutral for acne. Cocoa beans also contain polyphenols, plant compounds that the authors describe as having antioxidant and anti-inflammatory effects. Even so, acne worsened while people ate 50 grams a day.

The 2014 trial removed most of these ingredients by using unsweetened 100 percent cocoa in capsules. Spots still rose. That result suggests sugar is only part of the answer, and that something in cocoa may also play a role. No study has tested the ingredients one by one.

What the trials cannot tell you

The newer trials agree with each other, and they are still small. Together, 130 people finished them. Three of the four studied dark chocolate or pure cocoa, and none tested milk chocolate against dark chocolate. None lasted longer than 4 weeks, and none tested small amounts such as one square a day.

The 2024 guideline from the American Academy of Dermatology (AAD) reviewed this research. It found the evidence insufficient to make any recommendation about chocolate and acne treatment. The AAD's public page on diet does not discuss chocolate. NICE, which writes health guidance for England, says there is not enough evidence to support specific diets for treating acne.

Why chocolate might affect skin

Chocolate contains several things that could matter, and no study has shown which one does:

• Sugar. A 2022 review in JAAD International grouped chocolate with high glycemic foods, which raise blood sugar fast. Those foods have their own evidence, covered in high glycemic foods and acne.
• Milk. Milk chocolate contains milk, and cow's milk has its own link to acne, covered in milk and acne.
• Cocoa itself. The 2014 trial used unsweetened cocoa with no milk, and spots still rose.
• Cocoa butter. The 2024 trial authors suggest cocoa butter and sugar may be the ingredients that worsen acne.

There is a further possibility. The 2021 review says that where studies link sweets to acne, people with acne might simply eat more sweets. That explanation fits observational studies. It does not explain the trials, where the researchers chose who ate chocolate.

What surveys of diet show

Observational studies compare what people eat with who has acne. They give mixed results for chocolate:

• Kabul, 2019. In 279 young people with acne and 279 without, aged 10 to 24, chocolate and chips were both linked to acne.
• United States, 2006. In 6,094 girls aged 9 to 15 who reported their diets over 3 years, the 2021 review says there was no link between acne and chocolate.
• France, 2020. The 2021 review reports that in the French NutriNet-Santé study of 24,452 adults, eating milk chocolate was linked to current acne.
• JAAD International, 2022. This review lists several other surveys that linked chocolate to acne.

Deciding for yourself

If you eat chocolate most days and think it affects your skin, test it:

1. Take a photo of your skin in the same light before you start.
2. Stop chocolate for a month, the longest period the AAD suggests for testing a food. Keep everything else, including your skincare, the same.
3. Compare photos. The progress tracker keeps them in date order.
4. If you add chocolate back, keep taking photos so you can see any change.

If you have acne and eat chocolate only now and then, the trials give you little to act on: they tested 25 to 50 grams every day. A diet change works alongside treatment. The AAD says acne-friendly skincare and acne medicine help prevent new breakouts. For a routine built from a photo of your skin, analyze your skin.