Also, I'm very skeptical of the idea that bras lead to cancer due to restriction of lymph flow. The interpretation of research seems quite dodgy. For the sake of argument, I'll grant that 24-hour bra use is correlated with increased breast cancer. But it didn't take long to find a counterargument that overweight women are far more likely to wear bras that amount of time. Guess what being overweight is correlated with? Breast cancer. So all in all, this seems like the sort of argument that reinterprets correlation as causation. Also, a NYTimes article (which I understand might be rightly taken with a grain of salt) states that women with lymph nodes removed from the chest area don't have higher rates of breast cancer.
I'm not ruling out that not wearing a bra might be more comfortable or even that it might help if you are prone to cysts. But I'm reasonably confident that this one vanity is not going to have an unduly deleterious effect on my well-being. And unfortunately for me in light of my career plans, it seems that one of the more sound ways of decreasing risk of some kinds of breast cancer is having children early and often and breastfeeding them for a long time. But whatever, I couldn't care less if some of you other paleo ladies are happiest bra free
And for fun, a few studies in the research list at Bra Free - Bras and Breast Cancer
"Lymphadema due to chronic penile strangulation: a case report"
"Loosely-fitted polyester underpants on dogs caused dramatic decreases in sperm counts and an increase in degeneration of the testes." I would be most likely to interpret this as a result of psychological trauma!
Edit to include quote from Wikipedia article about the main source for that website: "Singer and Grismaijer claim to have noticed that the Māori of New Zealand, who are integrated into white culture and therefore wear bras, have the same rate of breast cancer, while the aboriginals of Australia, who are bra-free, have practically no breast cancer. The same was true for “Westernized” Japanese, Fijians and other bra-converted cultures." Sounds to me like there are other aspects of Western culture that could be confounding variables... http://en.wikipedia.org/wiki/Dressed_to_Kill_(book)