The foods in a child’s lunchbox could influence whether they experience their first menstrual cycle too early, according to recent research, which found that a more inflammatory diet was associated with a 15% greater chance of girls having their first period early, while a healthier diet reduced the risk by 8%.
An early start to menstruation isn’t just inconvenient, it’s a marker for chronic conditions, said senior study author Dr Holly Harris, associate Professor of Epidemiology at Fred Hutch Cancer Centre in Seattle. And younger generations are starting their periods earlier and taking longer to become regular.
An early first period, which is affected by both genetics and external factors, is associated with a higher risk of breast cancer, cardiovascular disease and diabetes later in life, Harris told CNN.
“This may be an important time period for lowering risk of chronic diseases that occur in adulthood,” she added.
It’s not just about weight
The study, published in the journal Human Reproduction, relied on data from more than 7 500 children aged nine to 14 enrolled in the Growing Up Today Study (GUTS). Researchers surveyed them in 1996 and 2004 and followed up in 2001 and 2008, respectively.
Researchers measured diets in two ways: the Alternative Healthy Eating Index, which rates foods and nutrients that predict chronic disease, and the Empirical Dietary Inflammatory Pattern, a dietary index that can assess a diet’s ability to affect chronic inflammation.
The study used well-designed statistical models to evaluate the connection between the quality of diet and age at which menstruation started, said Dr Zifan Wang, a research associate at Harvard TH Chan School of Public Health in the Department of Environmental Health. He was not involved in the research.
Late childhood
“Eating a healthy diet in late childhood and early adolescence is associated with girls having a later first period than those consuming a less healthy diet. Importantly, this association was not explained by the impact of diet on body size,” Harris said.
The previous understanding was that overeating high calorie foods may impact early menstruation because the accumulation of body fat signals hormones to initiate puberty.
But the connection was still there even when researchers accounted for body mass index, or BMI.
That means childhood obesity was likely not the only factor influencing the connection between early menstruation and diet – another factor related to unhealthy or inflammatory eating may be contributing, Wang said.
“Other pathways might be possible that are worthy of further investigation.”
Many environmental factors influence the age at which menstruation starts, including being exposed to high levels of air pollution and personal care products that may contain chemicals that can disrupt the endocrine system, Wang added.
There are also guidelines for the dietary patterns associated with reduction in the risk of early menstruation.
In this study, researchers assessed healthy diets as those that included fruits, vegetables, healthy fats, whole grains, and nuts and legumes, Harris said.
Those diets in the inflammatory pattern included red and processed meats, refined grains and sugar-sweetened beverages, which include soda, fruit juice and diet soft drinks.
“Our findings highlight the need for all children and adolescents to have access to healthy meal options, and the importance of school-based breakfasts and lunches being based on evidence-based guidelines,” she pointed out.
Study details
Dietary patterns and age at menarche in a prospective study of girls in the USA
C P Davis, S Fest, K Cushing-Haugen, T W Kensler, J E Chavarro, H R Harris.
Published in Human Reproduction on 6 May 2025
Abstract
Study question
Are dietary patterns associated with age at menarche after accounting for BMI-for-age (BMIz) and height?
Summary answer
We observed associations between both the Alternative Healthy Eating Index (AHEI) and the Empirical Dietary Inflammatory Pattern (EDIP) and age at menarche.
What is known already
Dietary patterns have been sparsely examined in relation to age at menarche and no studies have examined the association between the AHEI, a healthier diet, and EDIP, a pro-inflammatory diet, and menarche.
Study design, size and duration
The Growing Up Today Study (GUTS) is a prospective cohort of children ages 9–14 years at study enrollment. GUTS enrolled in two waves with enrollment beginning in 1996 (GUTS1) and 2004 (GUTS2). For this analysis, GUTS1 and GUTS2 participants were followed through 2001 and 2008, respectively.
Participants/materials, setting, methods
We included 7530 participants who completed food frequency questionnaire(s) (FFQ) prior to menarche who then self-reported age at menarche during study follow-up. Cox proportional hazard models were used to calculate multivariable hazard ratios (HRs) and 95% CIs for the associations between two dietary patterns, the AHEI and EDIP, and age at menarche, with and without adjustment for time-varying BMIz and height.
Main results and the role of chance
Six thousand nine hundred ninety-two participants (93%) reported menarche during the study period. On average, participants completed the baseline FFQ 1.75 years prior to menarche. Participants in the highest quintile of AHEI diet score (indicating a healthier diet) were 8% less likely to attain menarche within the next month compared to those in the lowest quintile (95% CI = 0.85–0.99; Ptrend = 0.03). This association remained after adjustment for BMIz and height (corresponding HR = 0.93; 95% CI = 0.86–1.00; Ptrend = 0.04). Participants in the highest quintile of the EDIP score (i.e. most inflammatory diet), were 15% more likely to attain menarche in the next month relative to those in the lowest quintile (95% CI = 1.06–1.25; Ptrend = 0.0004), and the association remained following adjustment for BMIz and height (corresponding HR = 1.15; 95% CI = 1.06–1.25; Ptrend = 0.0004).
Limitations, reasons for caution
Self-reported questionnaires are subject to some error; however, given our prospective study design it is likely this error is non-differential with respect to the outcome.
Wider implications of the findings
Our findings of an association between both the AHEI and EDIP and age at menarche indicate that diet quality may play a role in age at menarche independent of BMI or height.
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