Does consuming milk cause acne?

Have you ever heard other people say that consuming milk can cause acne? Are there any relationships between consumption of milk and the development of acne?

Acne, scientifically known as acne vulgaris, is a chronic, inflammatory, and immune mediated disease of the pilosebaceous unit (a single hair follicle and its associated sebaceous gland), highly prevalent in adolescents. Acne typically occurs on the face, trunk, and back, and may leave scars that affect people’s self-esteem and mental wellness (Bagatin et al., 2020). As a result, many female teenagers tend to use concealer or foundation to cover the acne or scars, but that won’t resolve the problem. Over decades, scientists have been working on finding the cause of the acne, but the scientific reason is still not completely understood. However, we know that our dietary habits may play an important role in the development, duration, and severity of acne (Dall’Oglio et al., 2021). And maybe milk plays an important role in contributing to the development of acne.

What causes acne

Nowadays, we know that there are at least four factors that play important roles in acne pathogenesis: hyperseborrhea (overproduction of sebum from follicles) and dysseborrhea  (a change in the sebum in acne patients), altered keratinization of the pilosebaceous duct (causes blockage of follicle preventing the natural cleaning that occurs by sebum), Cutibacterium acnes (C. acnes) and inflammation. The main hormones responsible for the development of acne are androgens, insulin, and insulin-like growth factor-1 (Cong et al., 2019). These are all internal factors that cause acne on our body, however, external factors, such as diet, stress, improper skincare habits or even environmental effects, can influence the development of acne. According to research done in 2019, cow’s milk and dairy products raise insulin-like growth factor-1 and insulin levels which can result in the growth of acne (Aghasi et al., 2019). Hence, there is likely to be relationship between the composition of milk consumed and the development of acne.

Milk influence on acne development

It has been proposed that dietary habits, especially in western dietary pattern, high glycemic index diet, and diet rich in omega-6 fatty acids can contribute to the development of acne. Add to this list another component of the western diet, milk.  Why? Milk and dairy products contain casein and whey protein that cause the rise of insulin-like growth factor-1 (IGF-1) and insulin concentration (Aghasi et al., 2019). Insulin-like growth factor-1 is a potent mitogen. IGFs bind specifically to the IGF-1 receptor on the cell surface of a target tissue, after binding, phosphoinositide 3-kinase (PI3K) is activated, which results in the activation of a kinase called AKT (also known as protein kinase B). AKT phosphorylates and thereby inactivates the transcription factors FoxO1 and FoxO3, which are proposed to play a key role in the pathogenesis of acne. FoxO1 acts as a negative nuclear coregulator off lipogenic transcription factors including androgen receptor (AR), SREBF1, PPARγ and of the pro-inflammatory transcription factor STAT3, those are all crucial transcription factors which promote sebaceous lipogenesis (fat synthesis). However, after AKT-mediated phosphorylation, nuclear FoxO1 is transported into the cytoplasm, where they are no longer active, resulting in the development of acne.

Mechanistic target of rapamycin complex 1 (mTORc1) also affects the development of acne. That’s because mTORc1 is a key growth factor and nutrient-dependent regulatory kinase orchestrating cell proliferation and anabolism and inhibiting autophagy, which has a special impact in regulating the protein translation of specific transcription factors involved in the pathogenesis of acne, including SREBFs, PPARγ, STAT3 and hypoxia-inducible factor-1α (HIF-1α). Does the consumption of milk affect the activation of mTOPc1? After people drink milk, the concentration of IGF-1 will increase, resulting in the phosphorylation of AKT. The activated AKT phosphorylates tuberin (TSC2), which reduces the stability of its interaction with hamartin (TSC1). The TSC1-TSC2 complex is a critical negative regulator of mTORC1. Scientists found that the activation of mTOPc1 can be one of the reasons that cause the development of acne. When we have a lower amount of TSC1-TSC2 complex, the mTOR1 can be activated and then the acne-related protein translation of specific transcription factors will increase, increasing the risk of developing visual signs of acne (Melnik, 2023).

 

Conclusion

The current results strongly suggest that milk consumption contributes to the development of acne on our body. Not only because it contains casein and whey protein, some research also suggests that the existence of iodine in milk may also result in development of acne (Aghasi et al., 2019). However, milk is also a good source of nutrients that benefits our health, especially for the growing teenagers.  It is important to find a balance of milk intake so that we can get the nutrients we want and not cause acne at the same time. According to the research, high intake of whole milk or dairy products, generally ≥3 times weekly, is necessary to cause acne in most people (Dall’Oglio et al., 2021). So, it you suffer with acne, next time you are pouring a cup of milk for breakfast think about how often and how much milk you are drinking. It just might help you spend less on acne medication.

Written by Jinyue Xu and edited by Aldrin V. Gomes, Ph.D.

References

Bagatin, E., & Costa, C. S. (2020). The use of isotretinoin for acne – an update on optimal dosing, surveillance, and adverse effects. Expert Review of Clinical Pharmacology, 13(8), 885–897. https://doi.org/10.1080/17512433.2020.1796637

Dall’Oglio, F., Nasca, M. R., Fiorentini, F., & Micali, G. (2021). Diet and acne: review of the evidence from 2009 to 2020. International Journal of Dermatology, 60(6), 672–685. https://doi.org/10.1111/ijd.15390

Cong, T., Hao, D., Wen, X., Li, X., He, G., & Jiang, X. (2019). From pathogenesis of acne vulgaris to anti-acne agents. Archives of Dermatological Research, 311(5), 337–349. https://doi.org/10.1007/s00403-019-01908-x

Aghasi, M., Golzarand, M., Shab-Bidar, S., Aminianfar, A., Omidian, M., & Taheri, F. (2019). Dairy intake and acne development: A meta-analysis of observational studies. Clinical Nutrition, 38(3), 1067–1075. https://doi.org/10.1016/j.clnu.2018.04.015

Melnik, B. C. (2023). Acne transcriptomics: Fundamentals of acne pathogenesis and isotretinoin treatment. Cells, 12(22), 2600. https://doi.org/10.3390/cells12222600