Expert: Dr. Kristina Conner - 5/25/2009

Question
I am a 27 year old woman and have been taking Flaxseed oil daily (1000 mg Nature Made) for the last 6 months (after having taken it most of last year, with a break of a few months).  I decided to add it to my daily vitamin regimen (which consistst of a multivitamin and calcium tabs) after reading about the benefits of Omega-3 fatty acids. I've noticed that my breasts are bigger than they were this time last year (They've gone from a 36B to about 36C) and believe the pills are responsible (as I haven't significantly changed anything else in my diet or daily practices).  Might flaxseed oil be increasing my estrogen levels and does this pose a health threat?  Have there been studies conducted on risks of taking flaxseed oil?  Should I continue to take the supplement?  Thanks in advance for your response!

Answer
Hello Bella,
Thanks for your question.  Flaxseed has a mild phytoestrogen effect, the ground seed more than the oil.  Phytoestrogens may be able to raise or lower estrogen levels depending on what the body requires.  So it's possible that it may have led to breast enlargement.  Besides changes in breast size, you may notice other estrogen-related issues such as menstrual changes.  Flaxseed oil is generally considered safe for long periods of time, especially a lower dosage such as the one you are on, but there are always individual reactions.  Phytoestrogens, when taken as food supplements, usually do not raise estrogen levels significantly, (in fact we often use them to balance high estrogen states like uterine fibroids) although again there is always the possibly of an individual reaction.  Without knowing your health history, I couldn't say for sure what is occuring or whether you should continue because of risks.  You always have a few options with supplements that may be causing an adverse effect.  1.  change the brand 2.  change the form (such as switch to fish oil for omega 3s) 3.  discontinue altogether for a set period of time  and then observe what happens in any of these cases.  You can always start again or try a different supplement.  
In health,
Dr Conner