How to Determine the Severity of Your Lactose Intolerance
Figuring out the extent to which you lactose intolerant, or physiologically intolerant of dairy products, isn’t clear cut and easy. Some people may be more or less able to tolerate dairy in their diets. In fact, some individuals diagnosed with lactose malabsorption, low lactase levels, or who fit the genetic profile for having low lactase levels don’t show symptoms of lactose intolerance — even when they’re challenged with a big dose of dairy.
The severity of lactose intolerance can be thought of as a spectrum or continuum with individuals in one of three main groups:
People who tolerate lactose in the diet very well: These lactose lovers all have something in common: They have ancestors from northern or northwestern Europe — Ireland, Scotland, England, Wales, the Scandinavian countries, and others. They have the ability to produce the lactase needed to digest milk sugars and can eat dairy products freely.
Scientists believe generations ago, people from these parts of the world developed a genetic mutation that allowed them to continue making lactase into adulthood. Long ago, many of these population groups were herders. The genetic mutation, or trait, they developed made it possible for them to drink the milk of the animals they raised. Over the generations, these Europeans passed this trait on to their descendents — mostly Caucasians — who today can eat a cheese sandwich or drink a milkshake without doubling over in pain.
People with little or no ability to produce lactase and digest dairy: This group contains the 75 percent of folks who have little or none of the preceding European decent. Most Africans, Asians, Hispanics, Native Americans, Alaska Natives, Pacific Islanders, and people of Mediterranean descent fall into this category. For these individuals, even small amounts of milk or milk products may cause a range of unpleasant symptoms.
People who fall somewhere in-between: These folks’ dairy tolerances depend on their own unique genetic makeup. In some cases, people of mixed ancestry may be able to eat cheese on pizza or a cup of yogurt now and then. Adding a glass of milk or dish of ice cream at the same meal, though, may be too much and cause symptoms to develop. How much is too much simply depends on the individual.
A 2010 report on lactose intolerance and health by the National Institutes of Health concluded that it’s impossible to accurately estimate the number of people in the United States who are affected by lactose malabsorption or lactose intolerance. In part, that’s because studies have been inconsistent in the way they define the condition. The bottom line is that the majority of the world’s adults are affected — whether they have symptoms or not — because many humans aren’t designed to digest milk after infancy.
The number of lactose intolerant people in the United States is likely to grow in the coming years. Census data shows that the nonwhite minority in the United States is going to be a majority by the year 2050. People in this minority are the most likely to be lactose intolerant.