Effects of Diet on Acne and its response to treatment

Written by Devika Mehta

Acne vulgaris is a common dermatologic condition, influenced by genetics,hormones,environmental factors and possibly diet.Historically acne was rare among certain populations however, with the incorporation of Western diets (processed foods,dairy, refined sugars) this changed. Although acne is most common among adolescents and young adults, acne after teenage years occurs more often in women. This article will explore how diet may influence the pathogenesis, persistence, and treatment of acne.

Acne pathogenesis is caused by several key factors, including excess sebum production, rapid growth of Cutibacterium acnes (C. acnes) bacteria, excessive buildup of keratin within the hair follicle and oil gland, and inflammatory mechanisms. 

In acne, excessive sebum (skin oil) is produced due to the increased activity of androgens (male hormones) and insulin-like growth factor-1 (IGF-1). IGF-1 activates a pathway called mTORC1, which promotes cell growth and increases metabolism in cells like sebaceous glands leading to sebum production. mTORC1 drives the overgrowth of sebaceous glands,lipid production and an increase in skin cell growth leading to buildup and clogged pores. Leucine (amino acid) from meat and dairy and hormone IGF-1 activate mTORC1, which promotes acne-related skin changes. IGF-1 also raises androgen levels which in turn continues to raise IGF-1, creating a cycle that amplifies sebum production and skin cell growth. Furthermore high insulin also raises IGF-1 and insulin-growth factor-binding protein-3. IGFBP-3 is a protein that controls how much IGF-1 is active. These can cause excessive skin cell growth and change how they die, further clogging pores. IGF-1 increases the gene for making protein SREBP-1 (sterol response element-binding protein-1), and when this SREBP-1 is active, it stimulates sebum production.Growth hormones and inflammation further contribute to acne.

Acne develops through numerous processes hence, there are many ways medicines can help treat it. The current treatmentents include topical agents, oral antibiotics, isotretinoin, hormonal therapies and physical interventions. These treatments work against the 4 factors of acne pathogenesis. While the treatment should be based on the severity and type of acne,oral isotretinoin is the only one which can directly or indirectly target all the known causes, hence is recommended for sevre cases. 

Several dietary factors have been implicated in the pathophysiology and severity of acne. GI and GL levels are higher in those with acne and consequentially diets with a low glycemix index and low glycemic load (Reduced intake of processed meats,bacon,added sugar,refined grains) has been found to reduce both the quantity and severity of acne lesions. It was observed that with mild-to-moderate acne, a low-GL diet resulted in significant reductions in non-inflammatory and inflammatory lesion counts, smaller sebaceous glands, decreased inflammation, and a reduction in acne severity grading. However, another study found no significant link between GI and dietary GL in patients with acne compared with those without acne, suggesting factors other than dietary GI and serum insulin levels may contribute to acne in some adult patients with post-adolescent acne.

While dairy and whey proteins may increase acne lesions, fat and fatty acids appear to reduce them. This theory is based on the high insulin index of foods such as milk and ice cream causing acne, while there is a lack of association between cheese (low insulin index) and acne. Omega-3 fatty acids reduce IGF-1 and inflammatory acne lesions, although increased trans-fats and saturated fat consumption increased acne severity. Acne patients may benefit from consuming omega-3 fatty acids or y-linoleic acid through supplements or food like fish. Probiotics/ probiotic supplementation have shown promising results to improve acne, while a vegetarian and vegan diet has shown no significant evidence in reducing acne, even with the reuduced dairy and leucine intake, hence this could be due to GL and GI. Ketogenic diets (near-total reduction in carbohydrate and increased consumption of fat and protein) causes the body to go through ketosis and reduce inflammation and levels of IGF-1. 

Chocolate has been extensively studied for its potential link to acne.Research shows a positive correlation between the quantity of cocoa ingested and the number of new acne lesions, however women were not included. Furthermore, it showed that the consumption of milk chocolate and sugary beverages was highly associated with current acne, however it is unclear if it's because of the high GI of these foods or the presence of acne increasing the intake of chocolate and sweets. 

 For an oral medication to achieve its desired effectiveness, several factors influnce its absorption and delivery to the target issue.The first is the inherent drug characterists such as the drugs solubility and permeabiliy which determine how well the drug dissolves in the gastrointestinal fluids and passes through the intestinal lining into circulation. Secondly, the gastrointestinal contents can heavily influence the absorption of medications, drug solubilty, stomach emptying-time (the time taken for the drug to reach the small intestine and absorb), gastrointestinal pH levels as well as forming indigestible complexes (components in food/supplements can bind with drugs to form insoluble/indigestable complexes.) and compete for emterocyte transportations(certain nutrients and drugs use the same transporters in the intestinal lining, hence with the presence of both, they may compete for absorption, reducing the uptake of one or both substances). All these factors can also influence the side effects of oral medications.

Drugs are classified into four categories based on their solubility and permeablilty. Class I drugs are highly soluble and permeable hence they have good absorption, however Class II drugs have low solubility but high permeability thus its absorption is improved with food, for example absorption of isotretinoin increases with high-fat meals. 

 A low GL diet can lead to better isotretinoin absorption, however this did not apply to topical benzoyl peroxide where no difference was seen between a low GL diet and control diet as both had a significant reduction in acne lesions. 

Tetracycline, doxycycline and minocycline are antibiotics commonly used to treat acne. For these antibiotics to work properly their concentration in the body must stay above a certain level during treatment. Food in the stomach can reduce the absorption of antibiotics such as doxcycline by 20%. Tetracyline which is absorbed less effieciently than doxycycline, is affected even more, especially when taken with dairy products, in contrast another antibiotic minocycline remains the least affected by stomach contents, and newer extended-release formulation of minocycline is not affected by food at all. Although studies show that both tetracycline and minocycline are absorbed less when taken with milk or food compared to water, with a greater reduction seen for tetracycline.Delayed-release doxycycline has similar overall absorption to the standard form, although it is absorbed faster on an empty stomach.

Dairy intake and acne treatment efficacy have little correlation, but whey protein supplements (protein found in milk) had a negative impact on oral antibitics,topical retinoids and benzoyl peroxide. When whey protein supplementation was discontinued acne rapidly completely cleared, however it came back within 1 week of reintroducing the supplement. This is because of the high proportion of leucine, an activator of mTORC1.

Minerals (calcium,magnesium,zinc,iron,aluminum) can bind tetracyclines, reduing their absorption and effectiveness, Minocyclines absorption is reduced mainly by dietary iron, hence supplements and antacids should be avoided a few hours before and after taking tetracyclines. Oral and topical zinc can be potential acne treatments, as oral zinc sulfate slightly reduced number and severity of acne lesions although reluts remain inconsistent

Isotretinoin is better absorbed with high-fat meals, and taking the conventional form wihtout fat can reduce the absorption and effectiveness. Lidose-isotretinoin (fat-based version of isotretinoin) performs similarly even when taken on an empty stomach, and a  newer micronized version dissolves better allowing twice as much absorption without food at a lower dosage.

Diet restrictions and complicated dosages make it difficult for consistent drug use. Antibiotics work better on an empty stomach, but food can help prevent gastrointestinal discomfort. Side effects and complex treatments can lead to delayed/missed doses and the neglect of food-drug interactions.

To conclude, diet plays a vital role in acne and its treatment, a low- GI/GL diet and the consumption of omega-3 fatty acids as well as probiotics strongly supports the reduction of acne. Milk and whey protein can worsen the number and severity of acne lesions and cause acne flares, however this was not the case for butter or cheese. More investigation into the effects of a vegetarian/vegan and ketogenic diet is needed, as antibiotics such as tetrcycline are heavily influenced by diet. Still, maximum absorption is seen under a fasted state without dairy. Although traditional isotretinoin is absorbed better with high-fat meals, lidose-isotretinoin does not require this for complete absorption. Patients should be informed about how their diet could enhance their therapeutic outcomes and possibly reduce the risk of relapse upon the stopping of treatment.

Baldwin, Hilary, and Jerry Tan. “Effects of Diet on Acne and Its Response to Treatment.” American Journal of Clinical Dermatology, vol. 22, no. 1, 3 Aug. 2020, www.ncbi.nlm.nih.gov/pmc/articles/PMC7847434/, https://doi.org/10.1007/s40257-020-00542-y.

Merriam-Webster. “Merriam-Webster Dictionary.” Merriam-Webster.com, 2025, www.merriam-webster.com. Accessed 15 Dec. 2025.