Understanding lactose intolerance

Lactase persistence, or the ability to retain the lactase enzyme and thus be lactose-tolerant, is inherited as a dominant trait. Lactase persistence is common in northern European populations. It is also evident in East African and Middle East pastoral populations.

On a recent trip to Tanzania, I observed local boys herding their goats and cows. Genetic mutations gave adults in these tribes the ability to digest milk. This resulted in more viable offspring; therefore, the percent of these populations that are lactose-tolerant increased as a result of natural selection.

People sometimes say that they are “allergic to lactose.” This shows a broad misunderstanding about the nature of lactose intolerance, which is quite different from a milk protein allergy. According to a National Dairy Council (NDC) Science Summary, “Lactose intolerance is a highly individualized condition, meaning the types and severity of symptoms, and the amount of lactose that triggers symptoms, varies among and within individuals.”

Range of products

There is no FDA definition for the terms “lactose-free” and “lactose-reduced,” but manufacturers must provide on their food labels information that is truthful and not misleading. We see virtually no products in the market with a “lactose-reduced” claim. Most brands opt to claim “lactose-free” or even “100% lactose-free.”

According to a Euromonitor International analysis, the lactose-free dairy category is expected to reach 9 billion euros (USD $10.1 billion) by 2022. Lactose-free milk is the largest category and represents two-thirds of the market, with a projected compound annual growth rate (CAGR) of 7.6% from 2017 to 2022. Lactose-free yogurt is the next largest category; it is projected to grow at a CAGR of 6.8%. Lactose-free cheese, meanwhile, has a projected CAGR
of 8.4%.

An excellent 2019 review of the lactose-free dairy category by Peter Dekker, senior scientist for DSM (https://tinyurl.com/y2j6ezj3), outlines market developments and technical innovations. Dekker’s article also reviews production processes for lactose-free milk, yogurt, cheese, powders and ice creams.

Fresh milk is typically produced using a batch method where the lactase enzyme is introduced prior to pasteurization. In contrast, for aseptic milk, the lactase enzyme is introduced after ultra-high-temperature treatment. In fresh milk, the enzyme is inactivated during pasteurization, so no residual enzyme activity remains in the final product. The batch process might provide some regulatory or labeling advantages.

Claims that dairy products are 100% lactose-free could reinforce the misperception that lactose-intolerant consumers should avoid all lactose. Rather, we should be encouraging these individuals to select from the wide range of dairy products that are naturally low in lactose or that have been formulated to be “reduced-lactose” or “lactose-free.”

NDC offers 12 tips for incorporating dairy foods into the diet: https://tinyurl.com/y4d8mch5. For example, natural cheeses such as cheddar, Swiss, mozzarella and many others typically contain less than 1 gram of lactose per serving. And in both regular and Greek yogurt, the live and active cultures help digest lactose.

With a bit of trial and adjustment, most consumers should be able to enjoy the great taste and nutrition of three servings of dairy per day.