Lactose
Lactation Celebration Month and World Chestfeeding Week Part 5: Lactose.
Today, I hope to help you understand the importance of lactose, why lactose intolerance in babies is misunderstood, and why researching lactose is so difficult. Jump in!
What is Lactose?
Lactose is a carbohydrate produced in all mammalian milk. Specifically, it’s a sugar compound (disaccharide) made from one molecule of glucose and one molecule of galactose. The total amount of lactose in milk varies from 2-8% of milk, depending on the species.
Lactose levels are lowest in colostrum.
Because lactose is created in the mammary gland, lactose levels in human milk are fairly similar between lactating parents, no matter their diet.
What is the purpose of lactose?
Lactose gives our babies energy. It comprises 40% of the total calories available in human milk.
It also has an immune building affect. When lactose is broken down by lactase, it splits into glucose and galactose. These form the building blocks of many human milk oligosaccharides (HMOs). HMOs build the good gut bugs which helps prevent bacteria and viruses from infecting our bodies.
Lactose may also protect the mammary gland and infant gut from infection by choosing microorganisms that cannot break it down.
Lactose has been found to enhance the absorption of calcium and magnesium, two essential minerals required by infants.
Lactose: Human milk vs Cow’s milk
Human milk is about 7% lactose while cow’s milk is about 4.8% lactose. Why the difference? It is thought that the high lactose levels promote the exceptional brain growth of human babies.
A human brain triples in size from 25% at birth to 80% of the adult brain size by age 3 years.
Should you give your milk to your baby if you’re lactose intolerant?
Yes.
Lactose intolerance comes from an absence of the enzyme, lactase, which breaks lactose back into 2 molecules (glucose and galactose). Infant lactase levels are quite low at birth but increase rapidly around day 5 (for preterm infants).
Starting around age 3-5 years, the production of lactase slows, with a sharper drop off in later childhood. Interestingly, the biological age of weaning for primates, including great apes (humans) is approximately 4.5-7 years, which matches our bodies natural ability to digest lactose.
A parent’s inability to produce lactase and digest lactose does not affect their baby’s digestion. Approximately 70% of the adult world does not produce lactose and is considered “lactose intolerant.” But if the majority of the world does not produce lactase, wouldn’t that be the norm? Perhaps we should say that 30% of the adult world retains lactase production and should be doing research to find out more about this anomaly.
Can my baby be lactose intolerant?
Yes, however, congenital lactose intolerance is extremely rare.
Secondary lactose intolerance is more common and results from damage to the cells that produce lactase. In the intestines, there are microscopic folds in which lactase is produced. Any damage to the intestinal lining can cause a disruption in lactase production. Common ailments affecting the quality of the intestinal lining include (but not limited to):
Gastorenteritis
Food allergies or sensitivities (via human milk)
Infections
Celiac disease
A baby with secondary lactose intolerance needs to heal the gut in order to restart lactase production. It is not a true lactose intolerance.
Galactosemia is a rare condition in which galactose (from lactose) cannot be used by the body. Galactosemia is not compatible with human milk feeding and is not physiologically related to lactose intolerance.
Research warning:
If you’re wanting to do your own research on human milk ingredients, you’re going to have to dig deep for anything more than surface information. If you find what looks like a reputable resource, check to see who wrote the article and who funded the research.
Before you proceed, this has nothing to do with formula being good or bad. Formula is very necessary for many babies. The marketing of formula is where the problem lies. It is so pervasive and engrained in our culture that it has made formula feed the societal norm.
It is very difficult to research lactose without getting bombarded with information from the dairy and formula industries. Websites with official sounding names (oooh, a ‘consortium’ must be reliable…no) are discovered to be financially backed by formula companies. Even the American Academy of Pediatrics is sponsored by formula companies (Abbott Nutrition makes Similac formula). There is so much money thrown at researching cow’s milk. While research is costly, both the dairy and formula industries profit handsomely from it. The financial bias cannot be disconnected from the research.
Human lactation is wellness promotion. It is preventative medicine. But there is little money to be made from a baby who consumes meals from a sustainable resource and who rarely gets sick.