Daughters of women with breast cancer or who have a harmful BRCA mutation are at higher risk for breast cancer than the general population. While parents have limited control over strongly genetic breast cancer risk factors, there are other sources of risk that they can influence. Now a new study has reported that a healthy diet may delay first period.

Childhood factors linked to early puberty

Early age at menarche (first period) is associated with increased risk of breast cancer in later life. The following risk factors for early puberty have been reported:
  • Consumption of sweetened soft drinks or soda, processed meats, and shellfish during childhood each have been found to be associated with early puberty in girls.
  • Exposure to phthalates and parabens both have been linked to early puberty. Note that while personal care products (e.g., shampoo and other hair products, body creams, and body oils) are intended for external use, some chemicals (including parabens) are absorbed through the skin or scalp.
  • Research has linked sunscreens and other UVF-rated personal care products containing benzophenones, octylmethoxycinnamate, or 4-methylbenzilidenecamphor to early puberty.
  • A number of hair care products marketed to African Americans contain harmful endocrine disrupting ingredients. Use of hair oil and perm, in particular, has been associated with earlier menarche among African-American girls.
On the other hand:
  • There is some evidence that vigorous exercise during childhood can help prevent early puberty.
  • A diet rich in fruits and vegetables with high vitamin A content has been reported to delay sexual maturation and carcinogen-induced mammary tumors in rats.

Latest research reports healthy diet could delay menarche

The prospective study referenced above was designed to investigate the associations between two dietary patterns, the Alternative Healthy Eating Index (AHEI) and the Empirical Dietary Inflammatory Pattern (EDIP), and age at menarche. The AHEI assigns ratings to foods and nutrients predictive of chronic disease. The EDIP is designed to assess the inflammatory potential of diet.
To conduct the study, the authors used The Growing Up Today Study (GUTS), a cohort of children aged 9 to14 years upon enrollment. GUTS enrolled two subcohorts, GUTS1 (enrollment began in 1996) and GUTS2 (2004). GUTS1 participants were followed through 2001 and GUTS2 participants were followed through 2008. The present study included a total of 7,530 participants who completed food frequency questionnaires prior to menarche, then self-reported age at first period during follow-up. Participants completed their baseline food frequency questionnaires 1.75 years prior to menarche, on average. The authors comment that self-reported questionnaires are subject to some error. However the prospective nature of the study means that it is unlikely that such errors significantly alter the results, according to the authors.
A total of 6,992 girls (93% of participants) reported first period during the study period. Participants in the highest quintile of AHEI score (i.e., the top 20% with the healthiest diets) were found to be 8% less likely to enter menarche during the next month compared to participants in the lowest (least healthy diet) quintile. This association remained after adjustment for BMIz (age and sex standardized body mass index (BMI)) and height.
Participants in the highest quintile of EDIP score (i.e., the 20% with the most inflammatory diets) were 15% more likely to enter menarche during the next month compared to those in the lowest quintile. This association also remained following adjustment for BMIz and height. The authors conclude that diet quality may influence age at menarche independent of BMI or height.
Please see our articles on protecting our daughters from breast cancer and reducing inflammation for more information.