Is soy isoflavones consumption associated with pubertal onset in boys?

Abstract

The estrogenic properties of isoflavones may adversely affect the pubertal development of boys who consume soy. Using an adolescent male population with a wide range of soy intake, we assessed if consumption of soy isoflavones is associated with age at onset of puberty using pubic (pubarche) and facial hairs as pubertal markers. Boys ages 12–18y (n=248) who attended schools near Adventist universities in southern California and Michigan self‐reported their age at onset of pubertal markers. Intake of soy isoflavones was assessed with a validated web‐based food frequency questionnaire. Consumption levels of isoflavones (total, daidzein and genistein) were categorized as low (<3 mg/d), moderate (3–20 mg/d), and high (>20 mg/d). Descriptives, time‐to‐event analysis, and Cox proportional hazards regression that controlled for confounders were performed. Energy‐adjusted mean (SD) intakes were 22.1 (30.8) mg/d for total isoflavones, 8.9 (12.6) mg/d for daidzein, and 11.3 (15.8) mg/d for genistein. Energy‐adjusted mean (SD) intakes of total isoflavones were 0.8 (1.0) mg/d for low, 10.1 (4.6) mg/d for moderate, and 54.9 (35.4) mg/d for high consumers. Compared to low consumers (13.00 y), adjusted median age at pubarche was significantly earlier by 5 months for moderate consumers, 12.58 y (RR [95% CI]: 1.58 [1.06, 2.36]), and by 6 months for high consumers, 12.50 y (RR [95% CI]: 1.63 [1.03, 2.60]). In a similar manner, daidzein and genistein consumption were also significantly associated with age at pubarche. No significant associations were found for facial hair onset for any of the isoflavones but adjusted median age at onset of facial hair was earlier for low consumers (13.67 y) compared to moderate (14.00 y) and high (14.01 y) consumers. Age at pubarche in this population with a wide range of soy intake is within the reported age range for boys' pubarcheal age but moderate/high consumers tend to have it earlier compared to low consumers. Further studies are needed to determine if isoflavones intake during childhood/adolescence affects male pubertal development.Support or Funding InformationLLU McClean Fund for Nutrition Research and Soy Nutrition Institute