Lactose intolerance is a common digestive condition that affects many individuals, rendering them unable to fully digest the sugar lactose found in dairy products. This inability leads to a range of uncomfortable symptoms, including diarrhea, gas, and bloating, typically occurring within 30 minutes to two hours after consuming lactose-containing foods or beverages. Although lactose intolerance, also known as lactose malabsorption, is generally harmless, it can significantly impact an individual’s quality of life.
The underlying cause of lactose intolerance is the insufficient production of the enzyme lactase in the small intestine. Lactase is responsible for breaking down lactose into two simple sugars, glucose and galactose, which are then absorbed into the bloodstream through the intestinal lining. When lactase levels are too low, undigested lactose travels into the colon, where it interacts with normal bacteria, resulting in the unpleasant symptoms of lactose intolerance.
It’s important to note that one can have varying levels of lactase production, and not everyone with lower levels will experience symptoms of lactose intolerance. However, when lactase levels are significantly deficient, it can lead to lactose intolerance and its associated discomfort.
Lactose intolerance is divided into three types, each with its own set of causes:
1. Primary Lactose Intolerance: This is the most common type and typically emerges as individuals age. Infants produce sufficient lactase since they rely on milk for their primary source of nutrition. However, as people shift from milk to other foods in childhood, the amount of lactase they produce diminishes but generally remains adequate for digesting the dairy typically consumed by adults. In primary lactose intolerance, lactase production sharply declines in adulthood, making it challenging to digest milk products.
2. Secondary Lactose Intolerance: This type occurs when lactase production decreases due to an illness, injury, or surgery involving the small intestine. Conditions associated with secondary lactose intolerance include intestinal infection, celiac disease, bacterial overgrowth, and Crohn’s disease. Addressing the underlying disorder might restore lactase levels and improve symptoms, although it can take time.
3. Congenital or Developmental Lactose Intolerance: While rare, some babies are born with lactose intolerance due to a lack of lactase production. This congenital disorder follows an autosomal recessive inheritance pattern, meaning both parents must pass on the same gene variant for a child to be affected. Premature infants can also develop lactose intolerance due to insufficient lactase levels.
Several factors can increase an individual’s or a child’s vulnerability to lactose intolerance:
1. Increasing Age: Lactose intolerance typically manifests in adulthood and is uncommon in infants and young children.
2. Ethnicity: Lactose intolerance is more prevalent in people of African, Asian, Hispanic, and American Indian descent.
3. Premature Birth: Premature infants might have reduced levels of lactase because the small intestine doesn’t develop lactase-producing cells until late in the third trimester.
4. Diseases Affecting the Small Intestine: Conditions such as bacterial overgrowth, celiac disease, and Crohn’s disease can lead to lactose intolerance.
5. Certain Cancer Treatments: Individuals who have undergone radiation therapy for stomach cancer or developed intestinal complications from chemotherapy are at a higher risk of developing lactose intolerance.
Diagnosing lactose intolerance is based on the patient’s symptoms and their response to dietary changes, particularly a reduction in dairy consumption. A healthcare provider can confirm the diagnosis through various tests, which may include:
1. Hydrogen Breath Test: This test involves consuming a liquid with high lactose content, followed by measuring the hydrogen levels in the patient’s breath at regular intervals. Elevated hydrogen levels indicate incomplete lactose digestion.
2. Lactose Tolerance Test: After drinking a lactose-rich liquid, blood tests are conducted two hours later to measure glucose levels in the bloodstream. A lack of increased glucose levels indicates an inability to properly digest lactose.
Lactose intolerance treatment strategies vary based on the underlying cause. In cases where lactose intolerance is a secondary symptom of an underlying condition, addressing the primary disorder might restore the body’s ability to digest lactose, although this process can be time-consuming.
For other forms of lactose intolerance, managing symptoms often involves adopting a low-lactose diet. This approach aims to reduce the intake of lactose-containing foods and beverages. Strategies for minimizing lactose intake include:
1. Limiting Milk and Dairy Products: Reducing the consumption of milk and other dairy items.
2. Including Small Servings of Dairy: Some individuals might tolerate small servings of dairy products better when consumed as part of a regular meal.
3. Opting for Lactose-Reduced Products: Some individuals can enjoy lactose-reduced or lactose-free versions of dairy products, such as ice cream and milk.
4. Using Lactase Enzyme Supplements: Liquid or tablet lactase enzyme supplements, like Lactaid, can be taken before consuming dairy to assist with lactose digestion.
For individuals with mild lactose intolerance, experimenting with various dairy products can help identify those that are better tolerated. Not all dairy products contain the same amount of lactose, with hard cheeses generally having lower levels and cultured milk products, such as yogurt, being more tolerable due to naturally occurring lactase-producing bacteria.
In addition to these dietary adjustments, it is essential to maintain adequate nutrition and calcium intake. Individuals with lactose intolerance can still obtain calcium from various non-dairy sources, including broccoli, leafy green vegetables, calcium-fortified products, canned salmon, or sardines, soy milk, rice milk, oranges, and certain nuts and beans. It’s also crucial to ensure sufficient vitamin D intake, which can be obtained from fortified milk, eggs, liver, yogurt, and sun exposure.
In some cases, individuals may choose to incorporate probiotics into their diet. Probiotics are living organisms that can support a healthy digestive system and might assist in lactose digestion. They are available in some yogurts and as supplements in capsule form.
When seeking medical advice for potential lactose intolerance, individuals should consult their family doctor. To prepare for the appointment, they can take several steps, including documenting their symptoms, medications, and supplements, and preparing a list of questions for the doctor. Some questions to consider might include:
- Are there other potential causes for my symptoms besides lactose intolerance?
- What tests are necessary to confirm lactose intolerance?
- What treatment options are available for managing lactose intolerance?
- Must I completely eliminate all dairy products from my diet, or can I consume them in moderation?
- How can I ensure I’m getting enough calcium in my diet?
- Should I consult a dietitian for guidance?
- How can I effectively manage any other health conditions I may have alongside lactose intolerance?
- Are there any informational resources or websites you recommend for further guidance on lactose intolerance?
In the meantime, individuals who suspect they may have lactose intolerance can keep a record of their daily dairy consumption, tracking what they eat and any associated symptoms. This information can be valuable in helping the doctor make an accurate diagnosis. Additionally, individuals can experiment with temporarily reducing dairy consumption to see if their symptoms improve.