Will I become intolerant if I cut out dairy?

October 18, 2025 •

4 min read

While about 65% of the world's population has some form of reduced ability to digest lactose as adults, the question, "Will I become intolerant if I cut out dairy?" is more complex and depends largely on genetics and how long you abstain. The body can reduce its production of the lactase enzyme when it is not needed, leading to temporary digestive issues upon reintroduction.

Quick Summary

This article explores the likelihood of developing lactose intolerance after eliminating dairy. It explains the role of the lactase enzyme, distinguishes between genetic and temporary lactase reduction, and provides a safe, step-by-step approach for reintroducing dairy into your diet to prevent or manage digestive discomfort.

Key Points

Genetics over habits: Your ability to digest lactose as an adult is determined by genetics, not by whether you regularly consume dairy.
Lactase production can decrease: Prolonged periods without dairy can cause your body to reduce the amount of lactase enzyme it produces.
Temporary, not permanent: Any intolerance symptoms experienced upon reintroducing dairy are usually temporary as your gut re-adapts and lactase production increases again.
Gradual reintroduction is key: To re-acclimate your digestive system, start with small amounts of lower-lactose products like hard cheese or yogurt.
Intolerance vs. Allergy: Lactose intolerance is a digestive issue, while a dairy allergy is an immune system response that can be severe.
Nutrient replacement is vital: If you go dairy-free long-term, ensure you get enough calcium, vitamin D, and protein from alternative sources.
Seek professional advice: Consult a healthcare provider or dietitian if you have questions about reintroducing dairy or managing a dairy-free diet.

Understanding Lactose Intolerance and the Lactase Enzyme

Lactose intolerance is not a disease or a true allergy; it is a digestive issue caused by the body's inability to fully break down lactose, the sugar found in milk. The small intestine produces an enzyme called lactase, which is responsible for this task.

For most mammals, lactase production naturally decreases after infancy, as milk is no longer a primary food source. However, a genetic mutation, known as lactase persistence, allows some human populations, particularly those with long histories of dairy farming, to continue producing lactase throughout their lives.

When a person with lactase non-persistence (meaning they lose the ability to produce adequate lactase) consumes dairy, the undigested lactose travels to the large intestine, where it is fermented by gut bacteria. This fermentation process causes the classic symptoms of lactose intolerance, including bloating, gas, stomach cramps, and diarrhea.

The 'Use It or Lose It' Misconception

The idea that completely cutting out dairy will cause you to become permanently intolerant is a common misconception. Your genetic predisposition for lactase persistence, or lack thereof, is the primary factor. If you are genetically able to produce lactase as an adult, this capacity will not be lost simply by abstaining from dairy. However, the body is highly efficient. If you stop consuming lactose for a prolonged period, your body may reduce the amount of lactase it produces because it is not needed.

When you suddenly reintroduce dairy after a long break, you may experience temporary symptoms of intolerance. This is because your system is not producing enough lactase to handle the sudden influx of lactose. In addition, the bacteria in your gut that help digest lactose may have decreased in number due to the lack of their food source. The good news is that for most people without a true milk allergy, this is often a temporary state. Your body and gut bacteria can adapt and ramp up lactase production again with gradual reintroduction.

The Difference Between Intolerance and Allergy

It is crucial to understand the difference between lactose intolerance and a dairy allergy, as they are often confused.

Lactose Intolerance vs. Dairy Allergy


Feature	Lactose Intolerance	Dairy Allergy
Cause	Inability to digest lactose (milk sugar) due to insufficient lactase enzyme.	Immune system overreaction to proteins in milk, such as casein and whey.
Body System Involved	Digestive system.	Immune system.
Symptoms	Bloating, gas, diarrhea, abdominal cramps.	Hives, wheezing, swelling, vomiting; can be severe or life-threatening (anaphylaxis).
Severity	Uncomfortable but not dangerous.	Can be severe and potentially life-threatening.
Treatment	Manage symptoms by limiting or avoiding lactose, using lactase supplements.	Strict avoidance of all dairy products.

If you experience severe reactions like hives or difficulty breathing after consuming dairy, you should see a doctor immediately, as this indicates a serious allergy, not intolerance.

The Process of Reintroducing Dairy

For most people who have simply avoided dairy for a while, reintroduction can be done gradually to help your gut re-adapt. This is not advised for those with a confirmed milk protein allergy.

Start Low and Slow: After an elimination period of a few weeks, begin with very small amounts of dairy and see how your body reacts. Try foods that are naturally lower in lactose first.
Choose Lower-Lactose Foods: Hard cheeses (like cheddar and parmesan) and yogurt with live, active cultures are typically easier to tolerate. The fermentation process in yogurt breaks down much of the lactose, and hard cheeses contain very little.
Consume Dairy with Other Foods: Having dairy with a meal, rather than on an empty stomach, can slow digestion and help lessen symptoms.
Listen to Your Body: Everyone's tolerance level is different. Pay close attention to your symptoms and adjust your intake accordingly. You might discover you can tolerate a small amount of cheese but not a glass of milk.
Use Lactase Supplements (If Needed): Over-the-counter lactase enzyme tablets or drops can be taken before consuming dairy to help break down the lactose and prevent symptoms.

The Nutritional Considerations of a Dairy-Free Diet

If you decide to remain dairy-free, forgoing milk and its products means you must find alternative sources for key nutrients. The most important of these are calcium, vitamin D, and protein, which are abundant in dairy.

Calcium: Non-dairy sources of calcium include leafy green vegetables like kale and broccoli, fortified plant-based milks (almond, soy, oat), fortified orange juice, canned sardines with bones, and tofu.
Vitamin D: Fortified plant-based milks and orange juice, fatty fish like salmon, and egg yolks contain vitamin D. The body also produces vitamin D when exposed to sunlight.
Protein: Dairy-free protein sources are numerous and include meat, fish, eggs, beans, lentils, nuts, and tofu.

When choosing dairy-free alternatives, it's important to read labels carefully. Not all products are fortified equally, and some, like organic options, may not be fortified at all. A registered dietitian can help you plan a balanced dairy-free diet to ensure all nutritional needs are met.

Conclusion: Your Body Can Readapt

Cutting out dairy does not cause a permanent intolerance, but it can lead to a temporary decrease in your body's ability to produce the lactase enzyme. The digestive discomfort experienced upon reintroduction is a natural adaptation, not a lifelong affliction. By reintroducing dairy gradually, starting with small amounts of lower-lactose products like hard cheese or yogurt, most people can rebuild their tolerance and continue to enjoy dairy in moderation. Always differentiate between a digestive intolerance and a potentially serious immune-system allergy. For personalized guidance on dietary changes and supplementation, consult with a healthcare provider or a registered dietitian.

For more detailed information on managing lactose intolerance and reintroducing dairy, you can consult resources like the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) guidelines.

Frequently Asked Questions

There is no set timeline, as it is not a direct cause-and-effect relationship. The body's lactase production may gradually decrease over weeks or months of abstinence, which can lead to temporary intolerance symptoms upon reintroduction.

Start with small amounts of dairy, preferably lower-lactose products like hard cheeses and yogurt with active cultures. Consume it with other food to slow digestion. Gradually increase the quantity and frequency, listening to your body's reaction.

No. If you have a confirmed milk protein allergy, you should never attempt to reintroduce dairy without strict medical supervision. An allergy is an immune response and can be severe.

Yes, over-the-counter lactase supplements can be taken just before consuming dairy to help your body break down the lactose and minimize symptoms.

Hard, aged cheeses like cheddar, Swiss, and parmesan contain very little lactose. Cultured dairy products like yogurt and kefir are also lower in lactose because the bacteria consume much of it during fermentation.

Ignoring lactose intolerance will not cause permanent harm, but it will continue to cause uncomfortable digestive symptoms. Managing your diet or using supplements is the recommended approach.

Yes, many plant-based milks like soy, almond, and oat milk are fortified with calcium and vitamin D to match or exceed the levels in cow's milk. Always check the nutrition facts label to ensure fortification.