When I was in Morocco, I heard about the nomadic Tuareg’s tradition to marry their daughters soon after their first period. Tuareg arents would be giving an increased amount of animal milk to their daughters on the verge of puberty as they said this would help to speed things along.
In the West, we do not have any cultural reasons for our daughters’ puberty to start early. At any age, it is the time of huge biological and psychological changes. The rising hormones can lead to powerful mood swings. If the girls feel unable to find and express their developing feminine selves, and if their emotions are not positively validated, all the puberty symptoms may appear with full force resulting in feelings of anger, physical illness and even depression. For very young girls who are not quite ready or able to embrace all that is happening, this may be quite a challenging time. We also have evidence that early puberty increases cancer risk later in life.
And yet, many girls have been entering puberty younger across most European and developing countries. Many studies focus on “endocrine disruptors”, especially from pesticides and chemicals found not only in food, but also in things such as toys, and even nail varnishes, and their role in affecting hormones of growing children. There are also fascinating studies connecting early puberty girls with absent fathers and/or not having older brothers.
There is, however, a very different and alarming connection pointed out by Maureen Minchin in her book “Milk Matters: infant feeding and immune disorder” – one of the most interesting and well researched books on breastfeeding there is – it reaches all the way to infancy, the time almost completely omitted by most research of premature puberty.
As many paediatricians have been concerned about the use of soy formulas because of their possible effects on child reproductive development and thyroid function (because soy contains plant-based substances that mimic the hormone oestrogen). Minchin points out that cow’s milk formulas have been traditionally under-investigated and at the same time assumed to be safe. However, studies have found that cow’s milk formulas have comparable effects to soy formulas. In one study conducted by Arkansas Children’s Nutrition Center, researchers used ultrasound to assess the development of breast buds, uterus, ovaries, prostate, and testicular volumes in 40 breast-fed, 41 milk-fed, and 39 soy-fed 4 month old babies. This study found, quoted by Minchin: “Among girls…milk-fed infants had greater mean ovarian volume and greater numbers of ovarian cysts per ovary than did breastfed infants…Among boys…both formula fed groups had lower testicular volumes than breastfed infants”.
It is incredibly alarming to see differences in ovarian and testicular development in such young babies. Maureen Minchin asks the important questions: “What might be the effects by the time these children reach puberty, if they are being programmed already to develop differently? Do they reach puberty earlier than breastfed children?”
We know that, epigenetically, these changes would affect generations to come in ways we do not yet understand. We actually still don’t know how various formulas affect babies, and it is not clear from reading this study whether the parents of these babies were ever told about the findings nor whether they were given support.
We are all looking forward to seeing more long term studies, I am not just sure who would fund them, and who would be able to critically dismantle any findings and make them known.
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References and reading
Deardorff, J. (et al). 2011. “Father Absence, BMI, and Pubertal Timing in Girls: Differential Effects by Family Income and Ethnicity”. J Adolesc Health, May, 48(5) 441-447
https://www.theguardian.com/lifeandstyle/2010/oct/19/worried-about-early-puberty
https://www.theguardian.com/lifeandstyle/2009/mar/28/early-puberty-absent-fathers
Minchin M. 2015. Milk Matters: Infant feeding & immune disorder. This is also available here: http://infantfeedingmatters.com/infant-formulas-obesity-excerpt/
Varimo T. et al, (2017). “Precocious Puberty of Premature Thelarche: Analysis of a Large Patient Series in a Single Tertirary Centre with Special Emphasis on 6 to 8 year old Girls. 2017”. Available in: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5572337/
