Small breasts are making a fashion 'comeback.' Seriously?

Are breast sizes like hairstyles or hemlines, whose trendiness changes with time?

If so, small breasts are set to make a comeback, according to British-born fashion commentator Simon Doonan.

On the news site Slate, Mr. Doonan makes the case that even though large breasts are now widely considered to be desirable, breast sizes are subject to the whims of fashion.

"Despite the worldwide embrace of enormous knockers, I remain convinced that the pendulous pendulum will, at some point, begin to swing the other direction," Mr. Doonan writes. "I know what you are thinking: Only a gay man could seriously posit the notion that big boobs might 'go out of fashion.'"

However, he continues, he remembers a time when small breasts were in vogue.

During the late 1960s, he recalls, his straight male friends enthused about the "modest knockers" and "pert, little, no-brassiere-needed appendages" of actresses/socialites Anita Pallenberg and Michele Breton. And flat-chested women like Twiggy, Ali McGraw and Mia Farrow were regarded as cool and highly attractive.

Mr. Doonan says he began speculating that small breasts could become popular again after seeing actress Rooney Mara bare her modest, natural-looking pair in the U.S. film The Girl With the Dragon Tattoo.

Moreover, health concerns over leaky breast implants may force a shift away from large breasts, he suggests.

These days, even naturally well-endowed women are looking to downsize in the hopes of fitting in. Not convinced? Check out the BBC documentary "My Big Breasts and Me," in which women express frustration over unwanted attention over and feelings of self-consciousness about their large breasts, not to mention physical problems like backpain.

In an ideal world, breast sizes, whether large or small, wouldn't be deemed "fashionable" at all.

What do you think: Is breast size really comparable to a fashion trend?