The Health Benefits of Lactase

This supplement can be used as needed to treat lactose intolerance

Lactase is a digestive enzyme involved in the breakdown of lactose, a sugar found in milk and other dairy products. Lactase, produced in the lining of the small intestine, splits lactose into the smaller sugar molecules (known as glucose and galactose) so that it can be digested. However, some people are not able to produce enough lactase on their own, leading to a condition known as lactose intolerance.

People with lactose intolerance can experience an array of gastrointestinal symptoms whenever they consume dairy, including stomach cramps, diarrhea, and gas. Taking lactase supplements may reduce or prevent many of these symptoms.

lactase medicine pills and milk

Health Benefits

According to a 2019 study published the American Journal of Clinical Nutrition, around 70 percent of the world's population is lactase deficient, with the highest prevalence being among people of East Asian, West African, Arab, Jewish, Greek, or Italian descent. We now understand that a gradual decline in our ability to produce lactase after early childhood is a very common human trait. Fortunately, the majority of people with lactase deficiency never develop symptoms of lactose intolerance..

On rare occasion, lactose intolerance can occur at birth, a condition referred to as congenital lactase deficiency (CLD).

By taking lactase supplements, you may not only overcome symptoms of lactose intolerance but meet your dietary calcium needs. Doing so can help build and maintain healthy bones while reducing the risk of bone loss and osteoporosis.

In fact, according to a 2019 study in the journal Nutrients, lactose intolerance is a far greater risk factor for reduced bone density and fragility fractures than decreased dairy intake or the avoidance of dairy.

Lactose Intolerance

Despite the benefits of lactase supplements, there remains a paucity of research evidencing their effects. Although scientists agree that the supplements are safe, there has not always been consensus on how well they work.

According to a 2010 study in the European Review for Medical and Pharmacological Sciences, lactase supplements showed clear superiority in alleviating lactose intolerance compared to the probiotic Lactobacillus reuteri.

The 10-day study involving 60 adults showed that a single lactase supplement, taken 15 minutes before a meal, was better able to normalize lactose metabolization (as measured by a lactose breath test) than a 10-day course of L. reuteri. Moreover, lactose supplements were better able to alleviate key gastrointestinal symptoms, especially gas.

Despite the positive findings, a 2014 study in BioMed Research International reported significant variability in the response to lactase supplementation. Of the 96 adults given a lactose supplement, only 21.88% showed complete normalization using the lactase breath test, while 17.71% were fully non-responsive.

This suggests that other factors may contribute to the inability to metabolize lactose or, alternately, that other types of lactase may be needed to metabolize lactose in certain people.

Possible Side Effects

Lactase supplements are considered safe and well-tolerated with no known side effects.

However, people with diabetes need to use lactase supplements with caution. Once ingested, lactase is broken down into simple sugars that can increase your blood glucose level. While this may not cause any significant problems, it is important to check your blood sugar 20 to 30 minutes after taking a dose just to be sure.

On rare occasion, lactase supplements have been known to trigger allergic reactions. In one reported case, a woman who handled lactase supplements for her children but never took them herself experienced a severe, whole-body allergy known as anaphylaxis.

Call 911 or go to your nearest emergency room if you develop hives, rash, shortness of breath, wheezing, dizziness, lightheadedness, rapid heart rate, or the swelling of the face, tongue, or throat after taking a lactase supplement.

If left untreated, anaphylaxis can lead to shock, coma, respiratory or heart failure, and death.

Lactase supplements should not be used by women who are pregnant or breastfeeding as there is not enough information to ensure their safety. It is also unknown if lactase supplements can interact with other medications or supplements.

Dosage and Preparation

Lactase supplements are typically sold as capsules, chewable tablets, or powders. The standard dose is 6,000 to 9,000 international units (IU) taken immediately before a meal containing dairy. Others have found that adding 2,000 IUs of lactase powder to two cups (500 milliliters) of milk can help overcome symptoms.

If you are consuming excessive amounts of dairy or are eating over an extended period of time (such as at a picnic or banquet), you may need to "top up" with additional doses in 2,000-IU increments.

As a general rule, start at a low dose and gradually increase it until you achieve the desired control. Even though you cannot overdose on lactase, taking smaller amounts can save you money and have less effect on your blood sugar.

Lactase supplements can be stored safely at room temperate in a sealed container. Never use a supplement past its expiration date.

What to Look For

Widely available for purchase online, lactase supplements can be found in many natural foods stores, drugstores, and shops specializing in dietary supplements. You do not need a prescription to buy lactase supplements.

Dietary supplements are not strictly regulated by the U.S. Food and Drug Administration (FDA). To ensure quality and safety, look for brands that have been certified by an independent, third-party authority, such as the U.S. Pharmacopeia (USP), NSF International, or ConsumerLab.

Most lactase supplements are made from a compound called beta-galactosidase derived from the fermentation of the fungi Aspergillus niger or Aspergillus oryzae. Beta-galactosidase is often included in broad-spectrum digestive enzyme supplements, including vegan-friendly products like VeganZyme.

Other Questions

I take lactase supplements, but they don't seem to help. Why?

If you are still experiencing gastrointestinal symptoms after taking a lactase supplement, you may be taking them incorrectly. As a rule, always be sure to take a lactase supplement prior to the first bite of dairy. If eating for longer than 20 to 30 minutes, take another 2,000-mg dose to extend the protective benefit. Or, you may need to avoid lactose altogether.

Moreover, just because you are taking a lactase supplement doesn't mean you consume dairy with abandon. If you are lactose intolerant, it is important to control your intake, skipping the extra cream, cheese, or milk whenever possible (or, at the very least, cutting back on the amounts).

You may also want to consider if you are actually lactose intolerant. People will often diagnose themselves or their children as lactose intolerant when they, in fact, have an allergy to milk.

If you are unable to control your symptoms with lactase supplements, ask your doctor for a referral to a gastroenterologist or allergist for further investigation.

What are other sources of calcium beyond dairy?

While dairy products are a top source of calcium, it is possible to get ample calcium without them. If lactase supplements are unable to control your lactose intolerance symptoms, you can meet the recommended dietary allowance (RDA) of calcium—1,000 milligrams (mg) per day for women 18 to 50 and men 18 to 70—with these food sources:

  • Kale: 100 mg per cup
  • Bok choy: 74 mg per cup
  • Whole wheat bread: 30 mg per slice
  • Broccoli: 21 mg per 1/2 cup

A daily calcium supplement can also help you meet your need, especially if you are a woman over 50.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Itan Y, Jones BL, Ingram CJ, Swallow DM, Thomas MG. A worldwide correlation of lactase persistence phenotype and genotypes. BMC Evol Biol. 2010 Feb 9;10:36. doi:10.1186/1471-2148-10-36

  2. Voisin MR, Borici-Mazi R. Anaphylaxis to supplemental oral lactase enzyme. Allergy Asthma Clin Immunol. 2016;12:66. doi:10.1186/s13223-016-0171-8

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