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Lactose intolerance

  • Overview


    Lactose intolerance is characterized by an inability to fully digest the sugar (lactose) present in milk, resulting in gastrointestinal discomfort. Following consumption of dairy products, individuals experience symptoms such as diarrhea, bloating, and gas. This condition, known as lactose malabsorption, typically poses no serious health risks; however, its manifestations can be distressing.

    The primary cause of lactose intolerance is insufficient production of an enzyme called lactase in the small intestine. Lactase is responsible for breaking down lactose, enabling its proper digestion. While some individuals may have lower lactase levels and still manage to process milk products without issue, a marked deficiency in lactase can lead to lactose intolerance. Consequently, consuming dairy triggers adverse symptoms, underscoring the importance of proper enzymatic activity for lactose digestion.


    Colon and Small Intestine Function

    Within your digestive system, the small intestine and colon play essential roles. These components facilitate the digestion of the food you consume, extracting nutrients from it. While the intestines absorb vital nutrients, any unabsorbed content progresses through the digestive tract and eventually exits the body as stool during a bowel movement.

    Effective Management of Lactose Intolerance

    For many individuals with lactose intolerance, it’s possible to effectively manage the condition without completely eliminating all dairy products from their diet.

  • Symptoms


    Symptoms of lactose intolerance typically manifest within 30 minutes to two hours following the consumption of lactose-containing foods or beverages. Common indications encompass:

    • Diarrhea
    • Nausea, occasionally accompanied by vomiting
    • Abdominal cramps
    • Bloating
    • Excessive gas
  • When to see a doctor


    Abnormal symptoms may be a warning sign of potential dangerous diseases. Please contact our team of doctors immediately for detailed advice and update the most accurate and appropriate health care method.

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  • Causes


    Lactose intolerance arises when your small intestine fails to produce sufficient amounts of the enzyme lactase, necessary for breaking down milk sugar (lactose).

    Ordinarily, lactase facilitates the conversion of milk sugar into two simpler sugars—glucose and galactose—which are then absorbed into the bloodstream via the intestinal lining.

    In cases of lactase deficiency, undigested lactose in your food makes its way to the colon rather than being fully processed and absorbed. Within the colon, normal bacteria interact with the unprocessed lactose, triggering the characteristic signs and symptoms of lactose intolerance.

    Three distinct types of lactose intolerance exist, each stemming from diverse factors contributing to the underlying lactase deficiency.

    Primary lactose intolerance: The most prevalent form, primary lactose intolerance, initially involves sufficient lactase production during infancy. As children transition from milk to other foods, the production of lactase typically diminishes, yet it often remains adequate for digesting the amount of dairy found in a standard adult diet. However, with primary lactose intolerance, lactase production experiences a significant decline by adulthood, resulting in difficulty digesting milk products.

    Secondary lactose intolerance: This variation arises when lactase production in the small intestine diminishes following an illness, injury, or surgical procedure involving the small intestine. Conditions linked to secondary lactose intolerance encompass intestinal infections, celiac disease, bacterial overgrowth, and Crohn’s disease. Addressing the underlying disorder may eventually restore lactase levels and ameliorate the associated signs and symptoms, although recovery may take time.

    Congenital or developmental lactose intolerance: Although rare, some infants are born with lactose intolerance stemming from insufficient lactase production. This disorder follows an autosomal recessive inheritance pattern, meaning both parents must pass on the same gene variant for the child to be affected. Additionally, premature infants may exhibit lactose intolerance due to inadequate lactase levels.

  • Risk factors


    Factors that can heighten the susceptibility to lactose intolerance, for either you or your child, encompass:

    • Advancing age. Lactose intolerance typically emerges during adulthood, with the condition being infrequent among infants and young children.
    • Ethnic background. Lactose intolerance predominantly affects individuals of African, Asian, Hispanic, and American Indian heritage.
    • Premature birth. Prematurely born infants may exhibit lower lactase levels due to delayed development of lactase-producing cells in the small intestine, a process occurring late in the third trimester.
    • Small intestine disorders. Conditions affecting the small intestine, such as bacterial overgrowth, celiac disease, and Crohn’s disease, can lead to lactose intolerance.
    • Specific cancer treatments. Undergoing radiation therapy for stomach cancer or experiencing intestinal complications resulting from chemotherapy can heighten the risk of developing lactose intolerance.
  • Prevention


    While lactose intolerance cannot be completely prevented, individuals can adopt strategies to mitigate symptoms and improve their quality of life.

    1. Dietary Modifications: Adjusting dietary habits is central to managing lactose intolerance. Gradually reducing the intake of lactose-containing foods and beverages can help the body better tolerate smaller amounts of lactose. Incorporating lactose-free or low-lactose alternatives, such as lactose-free milk, yogurt, or cheese, can offer a convenient way to enjoy dairy products without triggering symptoms. Additionally, consuming smaller portions of lactose-rich foods during meals and snacks may aid in better digestion.
    2. Enzyme Supplements: Over-the-counter lactase enzyme supplements can be taken before consuming lactose-containing foods or beverages. These supplements help break down lactose, making it easier for the body to digest. They are especially useful when consuming dairy products that contain higher amounts of lactose.
    3. Probiotics: Probiotic-rich foods and supplements containing beneficial bacteria can help improve gut health and digestion. Certain probiotics have been shown to enhance lactose digestion and reduce symptoms of lactose intolerance.
    4. Balanced Diet: Maintaining a balanced diet that includes a variety of nutrient-rich foods can support overall digestive health. Consuming foods high in fiber, such as fruits, vegetables, whole grains, and legumes, can promote a healthy gut and aid in digestion.
    5. Hydration: Staying adequately hydrated is crucial for overall well-being and digestive health. Drinking plenty of water throughout the day can help alleviate digestive discomfort and support the body’s natural digestive processes.
    6. Consulting a Healthcare Professional: If symptoms of lactose intolerance persist or worsen, seeking guidance from a healthcare professional, such as a doctor or registered dietitian, is recommended. They can provide personalized recommendations and strategies to manage lactose intolerance based on individual needs and preferences.
  • *Please note that the information provided in the article is for reference purposes only. It is essential to consult a doctor before applying any of the suggestions mentioned.

Content Details

Medical info from Mayo Clinic, for reference only. Visit Hoan My for better advice.

Last updated on: 06/08/2023