There’s More to Breasts Than You Might Think

Breasts consist of skin, glandular tissue, connective tissue, ductal lobule units, ligaments, and fat. While breasts are always changing, they’re not considered completely mature until pregnancy or lactation occurs. “The ductal lobule units don’t get mature until they get the signal of lactation, or sometimes they just give up and fully mature about two years after we start our menstrual period,” says Amanda Wheeler, MD, breast surgeon at Stanford Health Care and clinical assistant professor of surgery at the Stanford University School of Medicine in California.

Once women enter the perimenopausal years — usually in their forties — changes that lead to sagging occur. “The ductal lobule units are no longer supported by hormones, because we’re not getting our menstrual period anymore. When that happens, they shrivel up and shrink. Then you get fatty replacement of the breast,” Dr. Wheeler explains. “Plus, as we age, connective tissue, which suspends the breasts up and acts as our natural underwire of the breast, gets stretched. The breast skin begins to lose elasticity, too, and both contribute to sagging.”