The benefits of having a small bust include not having back pain and being able to sleep on your stomach.
But experts have discovered another potential advantage: women with smaller breasts appear to produce milk with a higher concentration of lactose.
A team from the University of Warsaw recruited 137 women who were exclusively breastfeeding their babies and collected detailed data on each mother and each baby.
Breast size was measured, while breast milk samples were collected and analyzed in a laboratory.
They found that women with smaller breasts had higher levels of lactose in their milk compared to those with larger breasts.
Small breasts have one potential advantage: Women with smaller breasts appear to produce milk with a higher concentration of lactose.
Lactose is an essential component of breast milk, providing around 40 percent of the energy needed by babies and promoting the development of their central nervous system.
It also helps babies absorb calcium and iron.
However, no relationship was found between breast size and milk energy density, protein or fat content.
The researchers said hormonal factors could explain their findings, which were published in the American Journal of Human Biology.
Larger breast size has previously been linked to higher levels of the hormones estradiol and progesterone, which can decrease overall milk production and inhibit lactose formation.
“This is the first study to report a negative relationship between breast milk lactose concentration and maternal breast size during fully established lactation,” the scientists wrote.
“The demonstrated association indicates that women with larger breasts can, through hormonal control, produce milk with a lower lactose concentration than women with smaller breasts.”
It is recommended that babies consume only breast milk for the first six months of life.
After this, the advice is to continue breastfeeding, along with other foods, for two years and beyond.
A previous study found that women with larger cup sizes tend to have lower levels of satisfaction with their breasts.
Research involving 345 adult women revealed that those with large busts were more likely to report that they were dissatisfied with them and therefore felt less attractive and had less sexual confidence.
On the other hand, it was found that those who were happier with their breasts exercised more and reported a better quality of life.
The team, from the University of Canberra in Australia, said: “Our finding conflicts with social standards and beliefs that suggest that large breasts are congruent with femininity, beauty and sexual attractiveness.”