Lactose intolerance

Symptoms Of Lactose Intolerance

The symptoms of lactose intolerance usually begin 30 minutes to 2 hours after consuming lactose-containing products. The undigested lactose build up in the intestine and cause:

• Abdominal pain

• Bloating

• Loose stools

• Flatulence

• Borborygmi (a rumbling or gurgling noise made by the movement of fluid and gas in the intestines)

• Fullness

Rarely, the individual may also experience:

• Nausea

• Vomiting

• Headache

• Constipation

• Muscle pain

• Joint pain

The malabsorption of lactose produces several toxic chemicals such as acetone, acetaldehyde, ethanol, and peptides. This can lead to the appearance of some extra-intestinal symptoms which include:

• Memory deterioration

• Musculoskeletal pain

• Depression

• Anxiety

• Mouth ulcers

• Heart rhythm disorders

• Vertigo

Did you know?

The amount of lactose usually required to produce symptoms of lactose intolerance is about 8 to 12 oz (236 to 354 ml). However, the amount may vary from person to person.

Causes Of Lactose Intolerance 

What is lactose?

Lactose is a type of sugar present in the milk of humans and mammals except for sea lions and walruses. It is also present in the products derived from milk such as cheese and yogurt. Breast milk and cow’s milk contain approximately 7.2 g of lactose per 100 ml and cow’s milk contains about 5g of lactose per 100 ml respectively. 

During infancy, it provides a very good source of energy that helps in overall growth and development.

Interesting fact!
Lactose is the only sugar that does not increase the risk of dental caries.

How does the lactose digested and absorbed in the body?

The enzyme lactase present in the small intestine plays a very key role in the digestion of lactose.

Lactose contains two types of sugar molecules i.e. glucose and galactose. In the small intestine, lactose is broken down into these two simple sugars. The glucose is absorbed in the body and used as an energy source.

How does lactose intolerance take place?

The main cause of lactose intolerance is the deficiency or the inactivity of the lactase enzyme.

What happens if Lactose is not digested?

• Accumulation of lactose in the large intestine

• Bacteria present in the large intestine ferments lactose and produce gasses including hydrogen (H2 ), carbon dioxide (CO2 ), methane (CH4 ) and short-chain fatty acids (SCFA). 

• These gases affect the GI function and manifest as the symptoms mentioned above. 

What is the difference between lactose intolerance and cow’s milk allergy?

Cow’s milk allergy is a type of immune mediated reaction unlike lactose intolerance which occurs primarily due to the deficiency in lactase enzyme. The symptoms of lactose intolerance start to appear at 5-6 years of age in contrast to milk allergy which peaks during the first year of life. 

The distinguishing symptoms are skin rashes and swelling of the lips, tongue, and palate which are very less likely to appear in lactose intolerance. 

Types Of Lactose Intolerance 

There are four type of lactose intolerance depending upon the cause: 

Congenital lactose intolerance

• The congenital form is very rare and  characterized by absent or reduced activity of lactase enzyme from birth. 

• It is a lifelong disorder that is manifested through the very first time the infant consumes either breast milk or formula.

Developmental lactose intolerance

• It is seen in premature infants who are born at 28 to 37 weeks of gestation. 

• The premature infants have an underdeveloped intestine which leads to malabsorption of lactose. 

Primary lactose intolerance

• It is the most common cause of lactose intolerance, also known as adult type lactase deficiency.

• Normally, there is a gradual decline in lactase enzyme activity after weaning –the process of switching an infant's diet from breast milk or formula to other foods and fluids. But, in some individuals the activity of the lactase enzyme persists in adulthood also. Those in which the activity does not persist will lead to lactose intolerance.

Secondary lactase deficiency

• It occurs later in life due to some gastrointestinal illness such as gastroenteritis, giardiasis, or celiac disease. 

• These diseases damage the brush border of the small intestine that contains lactase enzymes. 

• It is usually reversible. 

Risk Factors For Lactose Intolerance 

Lactose intolerance is a non-preventable disease. But, there are following risk factors can initiate lactose intolerance or increase its severity:

Age: The risk of lactose intolerance is usually more in adulthood. 

Race: Asians, Americans, Hispanics, are more prone to lactose intolerance.  

Genes: Genes may also predetermine the production of lactase enzymes as well as gut microbiome, predisposing some to lactose intolerance. However, it is rare that someone is born with a lactase deficiency. 

Premature birth: The premature babies have a high risk of lactose intolerance due to inability of the underdeveloped intestine to digest lactose. 

Composition of gut microbiota: Certain bacteria present in the intestine ferment the lactose. The fermented products produce gas that increases the chances of developing symptoms of lactose intolerance. 

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Amount of lactose consumed: The severity of symptoms can be increased as the amount of lactose consumed is increased. 

Food accompanying dairy products: The chances of developing symptoms are also increased if the lactose containing food items are taken alongwith the high protein and fatty food such as meat and fish. These foods stay longer in the large intestine and trigger the symptoms. 

Gastrointestinal diseases: Some diseases may affect the brush border cells of the intestine. This can lead to the damage of lactase enzymes which can eventually cause lactose intolerance. The diseases include:

• Celiac disease

• Small intestinal bacterial overgrowth (SIBO)

• Gastroenteritis

• IBS-D

• Cystic fibrosis

• Inflammatory bowel disease (IBS)

• Enterocolitis

Anxiety disorders: It is also seen that anxiety and depression also increases the possibility of developing lactose intolerance. 

Cancer treatment: This risk of lactose intolerance increases if the individual has undergone chemotherapy or radiation therapy for the cancer of the stomach or intestine.

Diagnosis Of Lactose Intolerance

The diagnosis of lactose intolerance requires assessing the medical, family, and dietary history of the patient. The understanding of clinical history also helps in revealing the association between the ingestion of lactose and occurrence of symptoms.

Medical history is followed by physical examination in which signs of abdominal pain, tenderness, and bloating are evaluated. 

The commonly used tests for the diagnosis of lactose intolerance include:

1. Lactose breath test (hydrogen breath test)

This test is most commonly used for the diagnosis of lactose intolerance. It involves breathing into a balloon-type container every 30 minutes over a few hours, to measure the amount of hydrogen in the breath. High amount of hydrogen gas indicates the presence of undigested lactose, a marker of lactose intolerance.

However, certain factors can affect the test result by altering the intestinal bacteria flora:

• Use of some specific medications oral antibiotics, proton pump inhibitors, and aspirin

• Abuse of laxatives (stool softeners)

• Invasive procedures that require bowel cleansing with enemas

• Use of probiotics before the test

• Consumption of some foods such as beans, corn, white wheat, potatoes, and oats

2. Lactose tolerance test

This test measures the amount of glucose at regular intervals after consuming 50 gm lactose containing liquid. Readings are taken at 0, 60, and 120 minutes. The failure of the blood glucose levels to rise by 20g may indicate lactose intolerance. 

The test has good sensitivity except in some conditions such as diabetes and small bacterial overgrowth. However, the test is useful in instances where there is absence of bacteria that does not produce hydrogen and hydrogen breath test can not be utilized. 

Note: The measurement of breath hydrogen after ingestion of 25 to 50 g of lactose is more sensitive and specific than the lactose intolerance test.

3. Milk tolerance test

Normally, lactose is digested and absorbed as glucose. Lactose intolerance is characterized by malabsorption of glucose. In this test, 500 ml of milk is given to the individual followed by testing of blood sugar. A rise in blood sugar of less than 9 mg/dl indicates lactose intolerance. 

4. Stool acidity test

This test measures the pH of stool. Lactose intolerance is characterized by decrease in the pH of the stool. 

5. Bowel biopsy 

In this, a small portion of the small intestine is removed for examination. Any damage in the cells of the small intestine that produce lactase enzyme is checked. This test is invasive and hence it is rarely performed. It is also used to rule out secondary causes of lactose intolerance. 

Specialist To Visit

The symptoms of lactose intolerance resemble several other conditions such as irritable bowel syndrome (IBS) and milk protein allergy. So, it is very important to consult a doctor to confirm the disease. 

When to see a doctor?

The doctor consultation is required if:

• You are experiencing serious symptoms such as constant fatigue, joint pain, and headaches.

• Your health is not improving even after cutting out lactose from your diet

Preparation for the appointment 

Lactose intolerance is a disease that is based on dietary intake of lactose. So, it is very important to understand the occurrence of symptoms after consuming lactose-containing foods. 

• Keep a track of the number of servings of dairy foods such as milk, yogurt, cheese, and ice cream

• Prepare a list of medicines and supplements that you are taking

• Maintain a record of symptoms after taking dairy products

• Record the information regarding disappearance of symptoms after cutting dairy products.

Doctors that can help you with this are:

• Gastroenterologist

• Pediatrician

• Nutritionist 
  
  

Gastroenterologists specialize in diagnosing and managing digestive disorders like lactose intolerance. They also help to manage the conditions such as inflammatory bowel disease and celiac disease that may trigger lactose intolerance.

Parents of lactose-intolerant children can seek treatment from Paediatricians.

While, nutritionists can help in optimizing the diet for lactose intolerance.

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Prevention Of Lactose Intolerance 

Lactose intolerance is predominantly a genetic condition without many modifiable factors. However, dietary modification plays a crucial role in the avoidance of symptoms associated with lactose tolerance.

Studies suggest that adults can consume up to 12 g of lactose in a single dose with no or minimal symptoms. So, it is always advisable to look at the content of lactose in the serving before having. The following list includes food items to be limited and those that are allowed:

Foods to limit

• All kinds of milk: whole, low fat, non-fat, cream, powdered, condensed, evaporated, goat, acidophilus, and chocolate 

• Milk products like butter, cottage cheese, ice cream, creamy/cheesy sauces, cream cheeses, soft cheeses (brie, ricotta), mozzarella, whipped cream, frozen yogurt 

Milk and food items made from milk are not the only source of lactose. Lactose is also added in several foods to incorporate sweetness and softness. Individuals with severe intolerance should be aware about these products. Such food items with ‘Hidden Lactose’ include:

• Milk Bread 

• Baked goods like muffins, biscuit, waffle, pancake

• Processed breakfast cereals

• Mixes for cakes, pancakes, biscuits, and cookies

• Instant potatoes, soups, and breakfast drinks

• Margarine

• Salad dressings

• Candies and other snacks

Foods allowed 

• Lactose-free milk, soy milk 

• Lactose-free dairy, hard cheeses (Parmigiano Reggiano, Pecorino, Grana Padano, fontina, taleggio, provolone, Swiss), gorgonzola

• Fruits  and vegetables 

• Legumes 

• Cereals 

• Meat, fish, and eggs

Learn more about healthy food substitutes for people with lactose intolerance.
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Treatment Of Lactose Intolerance 

The treatment approach of lactose intolerance should be aimed to provide symptomatic relief along with improving the metabolism of lactose. 

Objective of treatment 

• To provide symptomatic relief 

• To increase the absorption of lactose

• To avoid the nutritional deficiencies of restricted diet

• To treat the underlying condition in people with secondary lactase deficiency

Treatment approaches

• Minimizing the lactose intake

• Using alternative nutrient substitutes

• Using enzymatic supplements or lactase supplements

• Retaining the amount of calcium and Vitamin D

Dietary modification

• The maximum tolerable dose of lactose is identified. This is done by avoiding lactose-containing dairy products for 2-4 weeks. It is followed by a reintroduction of dairy products that are low in lactose. The dose is gradually increased to determine the tolerable which the individual can safely consume without the occurrence of symptoms.

• Foods to be limited and those that are allowed have been discussed in the prevention section.

Lactase enzyme supplements

• Patients with mild lactose malabsorption may benefit from using lactase enzyme supplements. These supplements are taken whenever food containing lactose is consumed. 

• The main advantage of this treatment approach is that individuals can consume dairy products. This will not deprive the patient from nutritional benefits of milk products and avoid the risk of osteoporosis and other bone related disorders. 

Probiotics 

• Probiotics contain lactase-producing bacteria that help in the digestion of lactose.

• A significant amount of reduction is seen in the symptoms of lactose intolerance due to probiotics. 

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Nutritional supplements

Dairy foods are a very rich source of calcium. It also contains proteins and magnesium along with several other minerals. 

Lactose-free diets help in managing the symptoms but it will also abstain the person from nutritional benefits of the dairy products. So, it is important to augment the diet with other rich sources or supplements.

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Home Care For Lactose Intolerance

A few home remedies help in reducing the severity of symptoms that are associated with lactose intolerance. These include:

• Cocoa powder: Research suggests that cocoa powder aids in the digestion of lactose by reducing the emptying time of the stomach. So, it helps to ease symptoms such as abdominal pain, nausea, and vomiting associated with lactose intolerance. 

• Apple cider vinegar: It aids in the digestion of lactose. It also helps to curb digestive problems associated with lactose intolerance due to its acid-neutralizing effect. 

• Ginger (Adrak): It is a very useful home remedy to alleviate symptoms such as nausea and gas associated with lactose intolerance.

• Chamomile tea: It helps in reducing bloating by neutralizing stomach acid. 

• Yogurt: It is highly rich in good bacteria and helps in the digestion of dairy products. 

Did you know?

Fermented foods such as idli and dosa help in creating helpful bacteria in the digestive system. The consistent intake of such foods aids in reducing the symptoms of lactose intolerance. 

Complications Of Lactose Intolerance 

Dairy products, especially milk, are a very good source of calcium, vitamins (A, B12, and D). Restricting these products can lead to several complications such as:

• Osteopenia (weakening of the bones)

• Osteoporosis (severe case of bone loss)

• Malnutrition

• Weight loss

• Rickets (condition that affects bone development in children)

• Growth failure or delay

Alternative Therapies For Lactose Intolerance 

Homeopathy

Homeopathy has shown promise in the management of symptoms related to lactose intolerance. Some of these homeopathic medications include Magnesia muriaticum, Aethusa cynapium, Apis mellifica, and China officinalis.

Living With Lactose Intolerance 

The cases of lactose intolerance are on a rise. The following adjustments in daily life may prove to be beneficial: 

Restrict instead of avoid

Studies suggest that lactose-intolerant people can tolerate the following amount of lactose:

• Up to 12 g of lactose at once (about 250 ml of milk)
• Up to 24 g of lactose spread out across the day (about 500 ml of milk)

Most of the guidelines recommend the intake of tolerable amounts of lactose instead of completely eliminating lactose from diet. This helps in maintaining the optimum levels of calcium and Vitamin D. The following measures can be taken while consuming lactose-based products:

• Add low-dose lactose-based foods such as cheeses and lactose-hydrolyzed milk products.
• Eat fermented products to your diet since they are a good source of probiotics. It exerts beneficial effects on gastrointestinal microflora.

Identify the tolerable dose

The tolerable dose of lactose is different for every individual. The following steps can be followed to identify the dose:

• Go on a temporary lactose-free diet to obtain remission of symptoms 
• Introduce foods that have low lactose content and gradually increase the dose to determine the tolerable dose.

Find the right alternatives

Some low lactose-based foods such as yogurt can also cause symptoms in a few patients. This is due to the varying amount of lactose in different types of yogurt. Greek yogurt has the least amount of lactose and can be safely consumed. 

Plant-based alternatives are also available and can be consumed as per the individuals’s palatability and nutritional balance. Lactose-free vegan diets are increasing in the market due to their demand. There are several milk substitutes such as soy, almond, and rice milk which are completely lactose-free.

Eat in conjunction with other food

Lactose-intolerant people are advised to have dairy products along with other food items to reduce the symptoms of lactose intolerance. This is because other food items slow down the digestion process in the stomach.

Split the dairy foods

The low-dose lactose-containing food also should be divided into meals rather than eating in one go. This also helps in alleviating symptoms even after eating lactose. 

Read the labels

Most of the individuals are aware of the milk and dairy products that contain lactose. But, lactose powder is also used in several packaged foods to enhance their flavor. So, it is very important to read the labels of all packaged food items. 

Check on your vitamin and mineral intake

As dairy products are not an essential part of diet but they contain a lot of calcium along with other minerals. Calcium is required for the proper growth and development of bones and teeth. Children, adolescents, pregnant women, and older people need a higher amount of calcium.

Therefore, it is very important to add other food and drinks rich in calcium such as spinach or calcium-enriched soy milk. 

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Quality of life

Lactose intolerance impacts the quality of life and nutritional status of the individual due to restrictive diets. The fear that food will trigger symptoms can lead to anxiety in the long run. This anxiety makes the individuals feel that most foods will cause the symptoms. This form of behavior is categorized as avoidant/restrictive food intake disorder which can even cause weight loss. 

This can be avoided by making yourself aware about your maximum tolerable dose. In severe cases, seek help from a professional.