National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Galactosemia

Back to List of Questions
My 11 year-old grandson has galactosemia. He drinks soy milk all the time. Is one of the side effects of drinking so much soy estrogen or some hormone that can cause breast development? I haven't been able to find an answer to that question. Any information you can provide will be appreciated. Thank you.

The following information may help to address your question:


Is breast enlargement in teen boys normal?

Yes. Around the time of puberty, about 50 to 60 percent of boys experience breast enlargement.[1] In these boys, breast enlargement typically goes away within six months to two years of onset. This and more can be found at the following link to MedlinePlus.gov:
https://www.nlm.nih.gov/medlineplus/ency/patientinstructions/000650.htm
Last updated: 4/11/2016

What are other causes of male breast development?

In addition to puberty, male breast enlargement can also be caused by certain drugs (e.g., human growth hormone, 5-alpha-reductase inhibitors (such as finasteride/Propecia), liver scarring, malnutrition, kidney disease, hyperthyroidism, hypogonadism, and testicular tumors.[2]
Last updated: 4/11/2016

Can dietary soy cause male breast development?

From our review of the literature, it appears that this question remains incompletely resolved. The answer is likely complex and may depend on age and a variety of other factors.[3] Reports of feminization in humans consuming large quantities of soy are rare. Large population studies have reported small/subtle effects on growth.[4]

The Micronutrient Information Center at the Linus Pauling Institute, is a rich source for information on nutrients and diet. The following page summarizes what is known regarding Soy isoflavones (the phytoestrogens found in soy) and their effects (beneficial and detrimental) on health. For example the page explains that exposure to soy-based formula in infancy does not appear to affect health, growth, and reproduction. We did not find an article about soy consumption throughout infancy and childhood and risks however:
http://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/soy-isoflavones
Last updated: 4/11/2016

We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please contact us.

Warm regards,
GARD Information Specialist

Please see our Disclaimer.

  1. Johnson RE, Kermott CA, Murad MH. Gynecomastia - evaluation and current treatment options. Ther Clin Risk Manag. 2011; 7:145-8. Accessed 4/11/2016.
  2. Cuhaci N et al.,. Gynecomastia: Clinical evaluation and management. Indian J Endocrinol Metab. 2014; 18(2):150-158. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3987263/. Accessed 4/11/2016.
  3. Patisaul HB, Jefferson W. The pros and cons of phytoestrogens. Front Neuroendocrinol. 2010 Oct; 31(4):400-19. Accessed 4/11/2016.
  4. Jargin SV. Soy and phytoestrogens: possible side effects. Ger Med Sci. 2014; 12:Doc18. Accessed 4/11/2016.