ByeAcne/Problem
Does Sugar Cause Acne?
High-glycemic diets — sugar, white flour, sweetened drinks — are linked to acne severity in controlled trials. The effect is real but moderate.
Reviewed by a licensed physician · Updated May 2026
Sugar and refined carbohydrates have stronger evidence for acne contribution than almost any other dietary factor. Multiple randomized controlled trials — actual interventional studies, not just observational associations — show that low-glycemic-load diets reduce acne severity over 12 weeks in treated patients. The effect size is modest (typically 20-30% reduction in lesion counts) but real, reproducible, and clinically meaningful.
The landmark studies: Smith et al (2007) randomized 43 young men with acne to either a low-glycemic diet or a control diet for 12 weeks. The low-glycemic group showed significant acne improvement, lower BMI, reduced insulin resistance, and changes in sex hormone profiles favoring lower androgen activity. Kwon et al (2012) replicated similar findings in 32 Korean adolescents. Subsequent meta-analyses support the pattern.
The mechanism is well-characterized. High-glycemic foods — sugar, white flour, sweetened drinks, refined cereals — spike blood glucose, which spikes insulin. Sustained high insulin increases IGF-1 (a growth factor that stimulates sebum production and follicular cell turnover), increases androgen activity in women (lower SHBG, more free testosterone), and promotes inflammation systemically. All of these favor acne formation.
What to actually cut: the biggest acne-relevant changes come from reducing sugary drinks (soda, sweetened coffee, juice, energy drinks), refined grains (white bread, pasta, most breakfast cereals, pastries), candy and desserts, and processed foods with added sugar (granola bars, condiments, salad dressings). Whole grains in moderation, fruits with their fiber, and protein-rich meals have minimal glycemic impact and aren't the target.
A practical 12-week trial: replace sugary drinks with water or unsweetened beverages. Switch refined grains to whole grain alternatives (and reduce overall portion size). Limit added sugar to <25g/day (the AHA guideline). Don't obsess over avoiding all sugar — sustained moderate change is more effective than brief perfectionism.
Diet alone is rarely sufficient for moderate-severe acne. Combine dietary attention with topical treatment (retinoid + benzoyl peroxide) for best results. For severe or hormonal acne, dietary change is supplementary to medical treatment, not a substitute.
Why "low-glycemic" matters more than "low-sugar"
Glycemic index measures how quickly a food raises blood sugar. White bread has a higher glycemic index than table sugar; both raise insulin more than steel-cut oats. Focusing only on "sugar" misses the bigger picture — most refined carbohydrates are more glycemic than the sugar in your coffee. The interventional studies use low-glycemic-load diets specifically, not just low-sugar diets.
Practical glycemic-load reduction: eat protein and fiber with each meal (slows carbohydrate absorption), choose whole grains over refined (lower glycemic index), avoid sugary drinks entirely (highest glycemic load per calorie), pair carbohydrates with fats (further slows absorption). These shifts produce more stable insulin levels and reduced sustained IGF-1 stimulation, which over weeks translates to reduced acne severity in responsive patients.
Treatment options a doctor may consider
- 12-week low-glycemic trial
Replace sugary drinks, refined grains, candy with whole foods. Photo diary weekly.
- Cut sugary drinks first
Highest-impact single change. Water, unsweetened tea, black coffee.
- Whole grain swap for refined
Brown rice for white, whole wheat for white, oats for refined cereals.
- Pair with topical regimen
Diet supplements rather than replaces medical treatment. Combine for best results.
Your specific regimen depends on your medical history, current medications, and intake photos. Only your physician can determine what's appropriate.
Who this applies to
Anyone with moderate acne whose diet includes substantial refined carbohydrates or sugary drinks. Especially relevant for patients whose topical treatment has plateaued and who haven't addressed dietary contributors.