Flaxseed, Yes or No?

One of the nurses who is currently finishing her treatment for breast cancer came back to work last week. We chatted about her peach fuzz, how she was feeling, compared radiation tattoos and then started chatting about nutrition. We discussed the lack of research on GMOs, avoiding soy protein isolate and she mentioned that she was on an aromatase inhibitor and not tamoxifen and that her doctor told her she couldn't eat flaxseed. I told her that I had heard nothing of it and that I would fact check it.

Rundown:

Like all nutrition studies it is hard to tease out if the one thing that people are eating, in this case flaxseed, is truly what is effecting outcomes.

• In short term studies 1 to 4 tbsp altered estrogen metabolism that may protect against breast cancer, and these effects are heightened in overweight and obese individuals and post menopausal woman
  
• Could flaxseed interfere with tamoxifen? There are no human studies currently reporting. But, in mice studies where the mice were injected with ER+ breast cancer flaxseed meal maintained the effectiveness of tamoxifen.
  
• Aromatase inhibitors have not been studied
  
• Flaxseed may slow or decrease absorption of medications

Bottom line: 
Flaxseed may be beneficial. I'll continue to add it to my granola and banana bread. And I'll tell the nurse that the studies are still out for her and flaxseed.

Source:
Collins, K. Flaxseed and Breast Cancer. American Institute for Cancer Research. March 2010.