This is a blog about baby products and today, we’re talking breast milk, a baby product from Nature. So much has been written about breastfeeding. We all know “breast is best.” But I’m constantly learning more, especially when I interview experts, such as Miriam H. Labbok, M.D., M.P.H., director of the Carolina Global Breastfeeding Institute at the University of North Carolina. Did you know, for example:

–Breast milk changes during the course of each feeding. In the beginning, it’s thin and salty. At the end, it’s rich and fatty, which contributes to satiety. “It tastes like a mild milkshake,” Dr. Labbok says.

–Expressed breast milk differs from breast milk straight from the spigot. “The second you put breast milk on a shelf—as in, in a bottle in the fridge—the fats begin to break down. In fact, all the components begin to change. Still, pumped breast milk will do. “If you can’t breastfeed, then expressing your milk is definitely the way to go,” Dr. Labbok says. But pumping because you don’t want to breastfeed directly? Not such a great idea, Dr. Labbok says.

–Sight doesn’t stimulate letdown. If you’re pumping at work, don’t bring your baby’s photo to stimulate letdown. Bring your baby’s worn T shirt instead. A baby’s smell has a lot more to do with the mother/baby relationship than sight. “Your baby’s smell can convince your body that your baby is nearby,” Dr. Labbok says.

—Breast milk naturally contains iron. Breast milk contains lower levels of iron than fortified infant formula because the iron in breast milk is a highly absorbable iron and babies are born with a nice supply of iron too. The iron in breast milk gets absorbed in the small intestine and doesn’t make its way down to the colon, a.k.a. gut, where the bacteria live. “Iron in the gut is actually a little risky because bacteria love it too,” Dr. Labbok says.

–Some babies don’t tolerate breast milk. It’s rare, but it’s not unheard of for a baby to have trouble digesting breast milk. “There are some babies who just can’t handle lactose so they have trouble with all milks,” Dr. Labbok says. Lactose is a carbohydrate (sugar) found in human and cow’s milk “that’s healthful and appropriate,” Dr. Labbok says.