The study of over 24,000 French adults found that sweet and greasy fare — especially milk chocolate, sweetened drinks, dairy products, and sugary or fatty foods — all appeared to raise the odds for zits.
The new findings “appear to support the hypothesis that the Western diet (rich in animal products and fatty and sugary foods) is associated with the presence of acne in adulthood,” said the team led by dermatologist Dr. Emilie Sbidian, of Mondor Hospital in Paris.
“This new study confirms what I have always believed, that proper nutrition is an important component of acne treatment,” said Dr. Michele Green, of Lenox Hill Hospital in New York City.
The likely culprit? Foods’ effects on hormones, she said.
“One of the reasons that this high ‘glycemic’ diet — high in sugar — causes acne, is that it changes the normal dynamic of one’s hormones,” Green explained. “These high-sugar diets can cause a rise in insulin levels and this affects other hormones, which lead to the development of acne.”
Adding to that, Green said, “there are also ongoing studies looking into the hormones that cows are fed in their feed, which may also have an effect on the development of acne.”
The new study focused on acne in adults, not on people younger than 18 years of age. Unlike many prior studies, this one was especially rigorous.
Thousands of French participants filled out researcher-validated 24-hour dietary records over a two-week period.
In these food diaries, participants recorded all foods and drinks consumed, and at what amounts.
They also recorded any incidence of an acne outbreak.
The result: After adjusting for a number of confounding factors, certain foods — dairy, fatty and sugary fare — emerged as potential acne triggers.
Quantity mattered. For example, having one glass of milk per day bumped up the odds of an outbreak by 12%, and a glass of a sugary drink (such as soda) raised it by 18%.
But drink five glasses of either a sugary drink or milk in a day, and your odds of developing zits rose by more than twofold or 76%, respectively.
Fatty foods appeared to do people’s skin no favors, either: One portion of a fatty (think French fries, burgers) food or a sugary treat (sugared donuts, cookies) boosted the odds for an outbreak by 54%, the study found.
And “a complete meal of fatty and sugary products” upped the odds more than eightfold, Sbidian’s group reported.
Overall, “adults with current acne were found to be less likely to have a healthy dietary pattern,” the French team concluded.
And what about chocolate? Intake of milk chocolate did seem tied to acne risk, bumping up the odds for an outbreak by 28%, the researchers found. But consumption of less fatty dark chocolate was actually tied to a 10% lower odds for acne.
Healthier foods — such as vegetables, fish and more plant-based fare — were also tied to reductions in acne for adults, the findings showed.
For many, acne isn’t just a cosmetic nuisance, Green noted.
“Acne patients suffer from low self-esteem and depression, and many go on to have physical acne scars, which they carry on their face for a lifetime,” she said.
In fact, “acne is an extremely important and emotional issue that frequently gets neglected,” Green added.
The study was published online June 10 in JAMA Dermatology.