Can Drinking Milk Increase My Breast Size?

Plenty of myths passed down from older relatives or trumpeted on social media proclaim ways to boost your boob size. It's challenging to know which ones might be true and which are totally false. We asked experts to help us unpack common claims about your twin peaks.

Myth: Drinking milk can increase breast size

One popular myth making the rounds is that drinking milk—particularly, dairy milk—can increase your breast size. The theory is centered around the idea that milk contains estrogen from the cow's hormone production that is then passed on to the drinker, increasing their estrogen levels and boosting breast size.

However, there's no evidence this works, especially not after your breasts have already developed through puberty. While research has been done on young people going through puberty, it has shown chiefly that body weight and weight gain from drinking sugary, artificially flavored milk products are the real causes of bigger breasts.

"Drinking milk does not make your breasts grow," said Constance M. Chen, a board-certified plastic surgeon and breast reconstruction specialist in New York City. "Gaining weight makes your breasts grow, just as it makes the rest of your body grow."

Myth: Certain exercises can build your breasts

Many of you may recall repeating a particular chant from author Judy Blume while making jerky arm motions that were reported to help you increase your bust. While this grade school practice may have fallen by the wayside (thank goodness), there are still myths circulating that working out can increase your breast size.

"Breast size is not affected by any exercises; breast tissue is not muscular tissue, so exercises won't make breasts bigger," Chen said.

Although you can strengthen and build the muscles under your breasts, which may increase your bra size, you can't create new breast tissue.

"The more exercise you do, the more you strengthen your pectoralis muscle, but at the same time, the more breast fat you can burn," explained Alexander Zuriarrain, M.D., a quadruple-board-certified plastic surgeon with Zuri Plastic Surgery in Miami.

Strength training is incredibly beneficial but will likely lead to lower body fat and, often, reduced breast size.

Myth: Breastfeeding shrinks your breasts

Breastfeeding engorges milk ducts, which will be larger and heavier. But many people have claimed their breast size shrunk after breastfeeding.

"The engorged milk ducts empty after a woman finishes breastfeeding, a process called involution. The breasts will shrink during involution because the milk ducts are no longer engorged with milk," Chen explained.

Part of the reason breasts may appear smaller after breastfeeding and not fill out your bra as much is due to a change in shape rather than size.

"When the breasts involute after breastfeeding is completed, the breast skin does not always have the elasticity to snap back, so the breasts may appear saggier after breastfeeding," Chen said.

But these effects may be unavoidable whether you breastfeed or not. Your breasts become engorged due to pregnancy, and skipping breastfeeding to avoid sagging breasts is not likely to work. Instead, you'll miss out on some pretty incredible health benefits, such as protecting babies against some short- and long-term illnesses and diseases.

Myth: Stress causes your breasts to lose tissue

Another myth is stress causes you to lose breast tissue. Many people report smaller breasts due to a high-stress lifestyle. However, this change may have more to do with losing weight, which can happen when you're stressed.

"Stress can cause some women to lose weight, which might lead to proportionally smaller breasts that might appear to shrink," Chen said.

Conversely, stress can also cause weight gain, increasing breast size.

Myth: Eating soy makes your breasts bigger

Another food-related myth is that soy foods increase your breast size due to their estrogen-mimicking properties. This myth is also applied to males, with claims that men who eat soy, including soy milk, tofu and edamame, will grow breasts.

Eating soy or any other foods thought to impact your hormones does not increase your breast size, according to Zuriarrain.

Are there ways to make your breasts grow naturally?

"Some women are genetically predisposed to larger breasts, probably due to the hormone receptors in their breasts, whereas other women are genetically predisposed to smaller breasts," Chen said.

It's unlikely that you'll be able to shift the size of your breasts except through weight gain or loss. In general, weight gain leads to larger breasts, while weight loss is associated with smaller breasts, according to Chen. Your genetics also play a prominent role in breast size, limiting what's possible even with weight gain.