Holly Harris from the Fred Hutchinson Cancer Research Center and colleagues analyzed data from a prospective study and found that girls with a healthier diet reach menarche later. The analysis included data from 7,530 participants (aged 9–14 years) in two waves of the GUTS study, which were recruited in 1996 and 2004 and followed up in 2001 and 2008, respectively. All of them filled out questionnaires about their diet and reported the age at which they began menstruating. Diet was assessed using the AHEI and EDIP scales. Data were processed using Cox proportional hazards models. The results of the study were published in the journal Human Reproduction.
During the follow-up period, 93 percent of participants reached menarche. Girls in the highest quintile of the AHEI (healthiest diet for chronic disease) score were 8 percent less likely to experience menarche in the following month than those in the lowest quintile (p = 0.03). In turn, those in the highest quintile of the EDIP (most pro-inflammatory diet) were 15 percent more likely than those in the lowest quintile (p = 0.0004). These correlations persisted after adjusting for height and body mass index. Given that early menarche is associated with an increased risk of diabetes, obesity, cardiovascular disease, and breast cancer later in life, dietary interventions in childhood may be a potential preventive measure.