Eating chocolate may increase incidence and severity of acne by stimulating microorganisms that cause the condition, according to a team of Dutch researchers.
A study published in scientific journal Cytokine said that chocolate stimulated Propionibacterium acne or Staphylcoccus aureus, two microorganisms involved in the pathogenesis of the skin infection.
First in vivo study
The researchers from Radboud University in the Netherlands reached their conclusions by conducting experiments with both cells and on humans. Past studies have only used cells, making this the first to examine chocolate’s effect on acne with in vivo tests.
“We provide the proof-of-principle that chocolate consumption has the capacity to modulate the immune responses in vivo,” said the researchers.
“This first in vivo investigation of chocolate effects on microbial-induced inflammation not only shows that indirect effects of chocolate on the immune response may partly explain its influence on acne, but also suggest that chocolate may influence antimicrobial host defenses in general,” they continued.
100g for four days; seven people
About 8 in 10 preteens and teens have acne, along with many adults. About 17 million people in the US have acne, according to the Nemours Foundation.
The study examined incidents of acne on seven volunteers who were told to abstain chocolate a week before eating 100g of Milka (30% cocoa) every day for four days.
The scientists also examined the effects of cocoa flavonoids on cells.
They found that chocolate released more interleukin-1b and interleukin-10, cytokines which impact immune responses and can lead to acne.
They also found that chocolate inhibited production of interleukin-22, which can help guard against acne.
Research needed on various types
The researchers called for further research to assess whether low-fat chocolate, or varieties such as milk, dark and white had different effects.
The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), part of the US Government’s health department, says on a section of its website discussing myths about acne that “chocolate and greasy foods do not cause acne in most people”.
Chocolate and heart disease
Chocolate has previously been linked to many beneficial effects such as protection from heart disease, due to its antioxidant content.
The study authors stressed that they only examined the impact of organisms responsible for acne and not cardiovascular disease. But added: “The strong increase in interleukin-10 production induced by chocolate, albeit after stimulation with a non-related stimulus, may provide a possible explanation for the beneficial effects of chocolate in cardiovascular diseases.”
Cytokine 62 (2013) 40–43
‘Chocolate consumption modulates cytokine production in healthy individuals’
Authors: Stejara A. Netea, Sam A. Janssen, Martin Jaeger, Trees Jansen, Liesbeth Jacobs, Gosia Miller-Tomaszewska, Theo S. Plantinga, Mihai G. Netea , Leo A.B. Joosten