Does Dairy or Sugar Cause Acne?What the Studies Show

Ask about adult acne and someone will tell you to quit milk or sugar. Here is what the research behind that advice looks like.

Sugar and the glycemic load

“Low-glycemic” foods raise blood sugar slowly, like most fresh vegetables, beans and steel-cut oats.¹ Two randomized trials tested a diet built on them:

Trial	Who	Result
2007	43 young men, aged 15 to 25, for 12 weeks2	Pimple counts fell by about 24, against 12 on the usual diet2
2012, Korea	32 people with mild to moderate acne, for 10 weeks3	Fewer inflamed and non-inflamed spots3

The 2007 group also lost more weight, and the authors said more studies were needed to separate the effect of weight loss from the diet.² Neither trial studied adult women.

Dairy

Here the studies are bigger but weaker, because they ask people what they eat and look for patterns.

• A 2018 review pooled 14 studies with 78,529 children and adults up to age 30.⁴ Any dairy came with about 25% higher odds of acne, and a glass of milk or more a day with about 40% higher.⁴ The authors warned of bias across the studies and urged caution.⁴
• A 2019 review linked milk, including skim and low-fat, with acne, but found no link for yogurt or cheese.⁵
• In a study of 47,355 women, those who remembered drinking 2 or more glasses of skim milk a day in high school were 44% more likely to have had acne.¹ That relies on memories from decades earlier.

Studies like these can’t show that milk causes acne, only that the two turn up together.

What guidance says

UK guidance tells clinicians to advise people that there isn’t enough evidence for any specific acne diet.⁶ US dermatologists say more research is needed and suggest watching whether a particular food seems to trigger your breakouts.¹

Testing a food on yourself

1. Pick one suspect, such as milk in your coffee or a daily sweet.
2. Log your breakouts for a few weeks first, so you know your usual pattern.
3. Drop that one food and keep everything else the same, then see what happens over a day, a week and a month.¹
4. Bring it back. If the breakouts return, that’s a stronger clue than the first change.

If you cut out dairy, replace its calcium. Diet changes work alongside treatment, not instead of it. See why you’re breaking out as an adult and acne routine mistakes.

Try: “I’m 44 and breaking out along my jaw. I’ve cut out milk for two months with no change. What treatment would you suggest, and should my hormones be checked?”

Skin, Head to Toe covers this in Chapter 7, “The Jawline Report,” in a section called “Food, Stress and Makeup.” Its Skin Log tests one change at a time over twelve weeks, so a suspect food gets a fair trial before you give up a whole food group. See the book.