Why? The mammary glands are filled with lymphatic vessels, and this is how the breast drains toxins (and when the lymph poops out, you end up wtih lymphoma). Lymph is a fairly dense liquid, and to get it pumping you need movement (e.g., exercise moves muscles, which squeezes the lymph along), and, unattractive as this may be to us in the West, the free-swingin' National Geographic type braless breast naturally keeps the lymph moving as well.
If something impedes the cleansing process, an imbalance occurs and the sex hormone by-products become destructive molecules called free radicals that begin cellular damage (called lipid peroxidation) which could lead to breast cancer. Plus, smearing on the aluminum chlorhydrate right on top of your lympph glands (and, also blocking your sweat, another detoxification defense in the body)...doesn't sound so hot.
Some natural health advocates suggest breast cancer as a "culturogenic" disease (i.e., a disease occuring only in cultures where people wear bra), read more here.
On the other side, I did read a story once where a woman's underwire bra saved her life because it stopped a bullet, or something.
And, okay, the bra is not going to go away. I understand that it's a little difficult, especially in the warmer weather, to go without support. Soooooo....
I really like Cottonfield's bra top; soft princess seams, organic cotton, not too tight, could use this as a top as well. It also comes in an undyed color (and lighter fabric) that works well with lighter tops. Supportive but not too restrictive, a nice wide band at the botton.
(image courtesy of Cottonfield USA)
Camisole tops are another great way to cover up without restriction. Check out Doie Design's cami top--toxin free bamboo and genuine silk accents. I find this top great to layer under another tank top, plus it's so comfy you can sleep in it.
And, don't forget, bamboo is sutainable, breathable, and antimicrobial.
(image courtesy of Doie Designs)