If you find yourself unable to drink coffee with heavy cream or eat anything too cheesy without getting sick, then you could be lactose intolerant ― even if you never had a problem before.
Lactose is the natural sugar found in dairy products. According to the American College of Gastroenterology, our bodies rely on a digestive enzyme called lactase to help break down lactose into simple sugars (called glucose and galactose). The small intestine then absorbs these and they reach the bloodstream as nutrients.
If lactose isn’t properly digested, it moves to the colon and is broken down by fermentation. This results in uncomfortable symptoms like abdominal pain or cramping, excess gas, diarrhea and/or the sudden urge to have a bowel movement.
Approximately 75% of the world’s population loses their ability to digest lactose as they get older. We consulted with experts to figure out exactly why this happens, plus some advice on how to deal:
Why does lactose intolerance increase with age?
Drinking milk is necessary for our survival…at first.
“As infants, humans produce significant amounts of lactase to digest the lactose found in breastmilk,” said Linna Goelz, a naturopathic medicine doctor at Sonoran University of Health Science. “Historically, once breastfeeding was done, and solid foods were introduced, humans no longer consumed lactose-containing food.”
And because humans weren’t eating as much lactose-containing food, their bodies adjusted and naturally began “to produce less and fewer lactase enzymes over time, which means we are unable to digest dairy properly,” according to Goelz.
This “gradual reduction” of lactase production is called lactase non-persistence or acquired lactase deficiency. Dr. Janese Laster, a board-certified gastroenterologist and founder of Gut Theory Total Digestive Care, said that this is “a natural process occurring in the majority of humans” after infancy.
You might notice these symptoms as a kid, or they could pop up in adulthood, depending on how slowly your body’s production of lactase declines. Or you could be part of the approximately 25% of humans who don’t notice a change at all.
Your genes play a big role.
Ask your parents if they became more lactose intolerant with age, and that can give you a clue into your own future. “The ability to digest lactose into adulthood is contingent on the specific gene variants inherited from parents, influencing the level of lactase activity present,” Laster said.
She explained that your body’s ability to break down dairy depends on the person. “While some may struggle with digesting fresh milk, they might find relief in consuming certain dairy products like cheese or yogurt, thanks to the fermentation process that breaks down a significant portion of lactose,” she continued.
Dr. Menka Gupta, a functional medicine doctor at Nutra Nourish, noted that lactose intolerance is more common among people of Southeast Asian, East Asian, West African, Native American and Hispanic descent “because they’re more likely to carry the gene mutation (APvegetOA2, MCM6).” However, it could happen to anyone.