Getting older brings many natural changes to the body. While wrinkles and gray hair are easy to notice, many important changes happen behind the scenes.
One of the most overlooked is the gradual decline in certain enzymes that help keep the body functioning properly.
Among the most important is lactase, the digestive enzyme responsible for breaking down lactose, the natural sugar found in milk and dairy products. As people age, many produce significantly less lactase, which can make digesting dairy more difficult and lead to uncomfortable digestive symptoms.
Understanding why this happens—and what you can do about it—may help improve digestion, nutrition, and overall quality of life.
What Is Lactase?
Lactase is an enzyme produced in the lining of the small intestine. Its job is to break lactose into two simpler sugars—glucose and galactose—which the body can easily absorb and use for energy.
When enough lactase is present, dairy products are usually digested without any problems. However, when lactase production declines, lactose may pass into the large intestine undigested, where bacteria ferment it and produce gas and other digestive symptoms.
Why Does Lactase Decline With Age?
For many people, decreasing lactase production is a completely normal part of aging. After childhood, the body often produces less of the enzyme because it is no longer considered essential for survival.
This gradual reduction is influenced by genetics and varies widely around the world. Some populations continue producing high levels of lactase throughout adulthood, while others commonly experience a significant decline beginning in their teens or early adulthood.
Although aging itself doesn’t guarantee lactose intolerance, the likelihood of reduced lactase production increases over time.
Common Signs You May Be Producing Less Lactase
A decline in lactase doesn’t always cause noticeable symptoms. However, if enzyme levels fall low enough, you may begin experiencing:
- Bloating after eating dairy
- Excess gas
- Stomach cramps
- Diarrhea
- Nausea
- Rumbling or discomfort in the abdomen
Symptoms often appear between 30 minutes and two hours after consuming milk, ice cream, cheese, or other dairy products.
Lactose Intolerance Is Common
Lactose intolerance affects hundreds of millions of adults worldwide and becomes increasingly common with age.
It’s important to understand that lactose intolerance is different from a milk allergy.
A milk allergy involves the immune system and can cause serious allergic reactions. Lactose intolerance, on the other hand, is a digestive condition caused by insufficient lactase production.
Why Proper Digestion Matters
Good digestion helps your body absorb nutrients needed for strong bones, muscles, immune function, and overall health.
If dairy causes discomfort, some people avoid it altogether. While that may reduce symptoms, it can also lower intake of important nutrients such as:
- Calcium
- Vitamin D
- Protein
- Potassium
- Vitamin B12
If dairy is limited, these nutrients should be obtained from other foods or, if appropriate, through supplements after discussing them with a healthcare professional.
Ways to Manage Lower Lactase Levels
Fortunately, producing less lactase doesn’t necessarily mean giving up dairy forever.
Many people find relief through simple dietary adjustments.
Try Smaller Portions
Instead of drinking a large glass of milk, consuming smaller servings throughout the day may reduce symptoms.
Eat Dairy With Meals
Having dairy alongside other foods can slow digestion and make lactose easier for some people to tolerate.
Choose Naturally Lower-Lactose Foods
Certain dairy products contain much less lactose than others, including:
- Aged cheddar cheese
- Swiss cheese
- Parmesan cheese
- Greek yogurt with live cultures
- Butter (in small amounts)
These options are often better tolerated than milk or soft ice cream.
Consider Lactose-Free Products
Many grocery stores now offer lactose-free milk, yogurt, cottage cheese, and ice cream that provide similar nutrition without the digestive discomfort.
Lactase Enzyme Supplements
Over-the-counter lactase supplements can help some people digest dairy more comfortably when taken just before eating lactose-containing foods.
These products do not work for everyone, but many people find them helpful for occasional dairy consumption.
Other Digestive Changes That Occur With Age
Lactase isn’t the only digestive enzyme or process that changes over time.
As people grow older, they may also experience:
- Slower digestion
- Reduced stomach acid production
- Changes in gut bacteria
- Decreased muscle movement throughout the digestive tract
- Increased sensitivity to certain foods
Together, these changes can contribute to bloating, constipation, indigestion, or changes in appetite.
Supporting Healthy Digestion as You Age
Maintaining digestive health involves more than focusing on a single enzyme.
Healthy habits that support digestion include:
- Eating plenty of fruits and vegetables
- Choosing high-fiber foods
- Staying well hydrated
- Exercising regularly
- Managing stress
- Getting enough sleep
- Limiting highly processed foods when possible
These lifestyle habits can help support overall digestive function regardless of age.
When to See a Healthcare Provider
Occasional bloating after eating dairy is common, but persistent digestive symptoms should not be ignored.
Seek medical evaluation if you experience:
- Unexplained weight loss
- Blood in the stool
- Severe abdominal pain
- Ongoing diarrhea
- Symptoms that continue despite avoiding lactose
These signs could indicate another digestive condition that requires medical attention.
The Bottom Line
One of the lesser-known effects of aging is that the body often produces less lactase, the enzyme responsible for digesting lactose found in dairy products. While this natural decline can lead to lactose intolerance in many adults, it doesn’t necessarily mean dairy must be eliminated entirely.
Simple adjustments—such as choosing lactose-free products, eating smaller portions, or using lactase supplements—can often make dairy easier to tolerate while helping maintain a balanced diet.
If digestive symptoms become frequent or severe, speaking with a healthcare provider can help determine the underlying cause and identify the best treatment plan for your individual needs.
