Clinical Question: Does milk intake increase the risk of acne in teenage patients?
Study Design: Cohort (retrospective)
Synopsis: Many teenagers are concerned about acne and what they can do to prevent or minimize it. Investigators analyzed data from the Nurses Health Study, a prospective cohort study of 47,355 nurses in the United States with more than 90 percent follow-up. Participants with self-reported “severe” acne (approximately 40 percent of the cohort) completed a survey evaluating their food consumption from 13 to 18 years of age. The diet questionnaire was validated in a small subcohort of participants, but most completed it after more than nine years had passed.
Intake of whole milk and skim milk was associated significantly with an increased risk of acne. The odds ratios ranged from 1.16 to 1.44. No significant correlation was noted with consumption of soda, french fries, pizza, or chocolate. Intake of skim milk was associated more strongly with an increased risk of acne than was intake of whole milk. The authors reported the body mass index and onset age of menses for the participants, but no other demographics (e.g., race, use of birth control) were noted. Possible reasons for the association include the potential presence of whey proteins and hormones in the milk. It is uncertain whether soy milk or hormone-free milk would produce different results.
Bottom Line: Consumption of whole milk and skim milk is associated with a slightly increased risk of acne in teenage patients. This study design cannot, however, prove causation, and there is no evidence that decreasing intake will improve acne. It is important that teenage women have an adequate intake of calcium and vitamin D to aid in the growth and formation of bone. Although a number of nondairy products with added calcium have been introduced, physicians should not recommend decreasing the intake of dairy products to reduce the risk or severity of acne until better evidence is available. (Level of Evidence: 2b)