What is the best diet for people with lactose intolerance?

Liz Wood Alphabiolabs

By Liz Wood, Health Testing Specialist at at AlphaBiolabs
Last reviewed: 11/10/2023

In this article, we discuss lactose intolerance, what it is, and the best diet for people who are lactose intolerant, along with which foods to avoid.

What is lactose intolerance?

Lactose intolerance is a common digestive issue where the body fails to produce enough of the lactase enzyme, which is required to break down lactose in the body.

Most mammals are born with the ability to digest lactose, because it is the sugar found in mammalian breast milk.

However, for people who are lactose intolerant, the body produces little to no lactase, meaning that the sugar remains intact and is fermented by bacteria in the colon.

This fermentation process causes unpleasant symptoms such as bloating, flatulence, nausea, vomiting or diarrhea (sometimes followed by constipation).

There is no cure for lactose intolerance, but the symptoms can be managed by adhering to a lactose-free diet.

Learn more about lactose intolerance

What are the symptoms of lactose intolerance?

Symptoms of lactose intolerance can range from mild to severe depending on the person and how much dairy/lactose they consume.

Some people with lactose intolerance can handle a small amount of milk and dairy products with no issues, whereas others cannot consume even a small amount of dairy without the onset of symptoms.

The main symptoms of lactose intolerance include:

  • Bloating
  • Flatulence
  • Abdominal pains or cramps
  • Diarrhea (sometimes followed by constipation)
  • Nausea

These symptoms occur because of how lactose affects the digestive system.

For people who are lactase persistent (i.e. do not have lactose intolerance), lactose is broken down in the body into two smaller sugar molecules by an enzyme called lactase. These sugar molecules can then be absorbed by the body.

However, for people with lactose intolerance, their body produces little or no lactase. Without enough of this enzyme, lactose moves through the gut into the large intestine, where it is fermented by bacteria that naturally occur in the gut.

This fermentation process is what causes the unpleasant symptoms of lactose intolerance including bloating, abdominal pain, and flatulence. The presence of this sugar (lactose) in the large intestine also causes water to move into the intestine, leading to diarrhea.

Symptoms of lactose intolerance can go away entirely when a person stops consuming products containing lactose (milk and dairy products).

Order a Home Genetic Lactose Intolerance Test

Are there different types of lactose intolerance?

There are four different types of lactose intolerance: primary lactose intolerance (the type we test for at AlphaBiolabs), secondary lactose intolerance, developmental lactose intolerance and congenital lactose intolerance.

Primary lactose intolerance is a genetic condition whereby your body stops producing the lactase enzyme, which is needed to breakdown lactose, the sugar found in milk and dairy products.
Usually, people with primary lactose intolerance can digest lactose as babies, but this ability begins to decrease as they grow, with symptoms typically starting around the age of five.

Secondary lactose intolerance can be caused by a variety of factors including other gastrointestinal issues (e.g. celiac disease, Crohn’s disease and ulcerative colitis), gastrointestinal infection, or even taking certain antibiotics.

Although this form of lactose intolerance may be temporary, especially if the cause can be treated or managed appropriately, some people may experience permanent secondary lactose intolerance. These individuals will have to stick to a lactose-free diet for the rest of their lives.

Developmental lactose intolerance can occur if babies are born prematurely (usually before 37 weeks), before lactase production has started.

Developmental lactose intolerance usually resolves itself by the time the baby reaches gestational age (full-term), but it is important for medical professionals to monitor the baby to make sure they are getting the right nutrition.

Congenital lactose intolerance is a rare but serious genetic disorder where the body does not produce any lactase at all, even at birth.

This means that babies with this condition are unable to break down lactose, the main sugar found in breast milk and normal baby formula. This can cause adverse symptoms when the baby consumes milk, including diarrhea, weight loss and electrolyte loss.

For this reason, it is vital that congenital lactose intolerance is detected early so that the baby can receive the correct nutrition and ongoing care.

What foods should you avoid if you are lactose intolerant?

For people who are lactose intolerant, any food or drink items containing lactose including milk (from cows, goats, and sheep), whey, curds, cream, butter, cheese, and yogurt should be avoided.

Lactose can also be found in smaller quantities in many other food products including cookies, chocolate, breakfast cereals, candy, cakes, some processed meats, and packet mixes (e.g. pancake mix or soup).

Additionally, lactose is sometimes used as an additive in the food and drug industry because it has useful properties, such as extending the shelf-life of some foods, or as a diluent in some medications.

For this reason, if you are lactose intolerant, it is very important to check the labels on food, drinks, and medications before consuming.

When checking the ingredients list on food, drink, and medications, you should look for the following ingredients:

  • Milk
  • Whey
  • Curds
  • Cream
  • Butter
  • Cheese
  • Lactose

Lactose is not always listed as a separate ingredient, so it is important that you also check for the names of products known to contain lactose.

What foods can you eat if you are lactose intolerant?

Food and drink products that are labelled as ‘dairy-free’ or ‘suitable for vegans’ are usually safe to eat if you are lactose intolerant.

These days, it is much easier to follow a lactose-free diet due to the number of alternatives available on the market. Some food and drink items that do not usually contain lactose include:

  • Soya, coconut and almond yogurts and cheeses
  • Almond, rice, oat, and hazelnut milks
  • Food or drink items that have the ‘dairy-free’ or ‘suitable for vegans’ labels

However, you should still check the ingredients to make sure there is no lactose or lactose-containing products in these items, particularly if you are very sensitive to lactose.

Some people with lactose intolerance can tolerate small amounts of lactose, however some people are very sensitive to minute quantities.

Some people who are lactose intolerant may also have intolerances or allergies to some of the dairy alternatives listed above. Luckily however, lactose-free dairy products exist and can be purchased in most of the larger grocery stores.

Lactose-free dairy products are still made from animal milk and so have the same nutrients as normal cow, goat, and sheep milk, but also contain the lactase enzyme.

This enzyme is lacking in people with lactose intolerance, and so the addition of lactase helps to break down the lactose found in milk, making it safe for people with lactose intolerance to consume.

Can I eat or drink goat milk products if I have lactose intolerance?

Goat milk contains a slightly lower amount of lactose compared to cow milk, leading some people to suggest that goat milk and its products are a better alternative to cow milk if you have lactose intolerance.

However, while this may be true for some people, lactose is still present in goat milk and may cause symptoms in people with lactose intolerance.

Luckily, there are many dairy-free and lactose-free products available on the market that may be more suitable for a person with lactose intolerance.

Dairy-free products are made with alternative ingredients, like almond and hazelnut milk, whereas lactose-free milks and milk products are made from animal milk but contain the lactase enzyme, which helps to break down lactose in the body (the sugar found in milk and dairy products).

Can I eat yogurt if I have lactose intolerance?

Many types of yogurt are not suitable for people with lactose intolerance because they contain enough lactose to cause an onset of symptoms.

However, many people with lactose intolerance can enjoy Greek and Icelandic yogurts.

This is because of how these products are made. In full-fat and strained yogurts, like Greek and Icelandic yogurts, the whey – which contains the highest amount of lactose – has been removed.

This means that these types of yogurt could be suitable alternatives for a person whose lactose intolerance is not severe. They also provide certain health benefits, as they have a high protein content and contain gut-friendly bacteria, which help to promote a healthy digestive system.

However, if you have been diagnosed as lactose intolerant, it is always recommended that you speak to your physician before introducing lactose-containing products into your diet.

Some health professionals may recommend that you keep a food diary, to track the foods you have eaten, and any symptoms you experience. This can help determine how much lactose your body is able to tolerate before you experience symptoms.

Can I eat foods made from wheat, rye, barley, and oats if I have lactose intolerance?

Wheat, barley and rye products all contain the protein gluten, which should be avoided by people with food intolerances, sensitivities or conditions that can be triggered by gluten consumption.

This includes people with celiac disease, gluten sensitivity – also known as non-celiac gluten sensitivity – and certain bowel conditions.

If you have primary lactose intolerance, and do not have a gluten intolerance, you should be able to eat wheat, barely or rye without any issues.

However, these ingredients are often used to make food items such as cookies, pastries, cakes, and bread, some of which can contain milk products that might cause symptoms if you have lactose intolerance.

Oats are another type of cereal grain like wheat, barley, and rye. Like these other grains, oats are fine to eat on their own or in a food or drink item if you are intolerant to lactose, provided there are no other milk products present.

There are also food and drink products that use oats as an alternative to animal milk, which are available at most larger grocery stores.

Can I eat eggs or food made from eggs if I have lactose intolerance?

Because eggs are not a dairy product, it is safe to eat eggs if you are lactose intolerant.

However, it is important to remember that some food products containing eggs may also contain dairy/lactose in varying amounts.

If you have been diagnosed as lactose intolerant, you should always check labels on food items before consuming.

What milk can I drink if I am lactose intolerant?

There are lots of alternatives to animal milk on the market that are suitable for people with lactose intolerance.

Coconut, soya, almond, hazelnut, and rice milk are all good alternatives to cow, goat, and sheep milk, and you can even find dairy-free yogurts, butter, chocolate, and cheese that are made from some of these milks, too.

They are also safe if you have an allergy to some proteins found in animal milk.

Many people enjoy these alternatives and are happy to substitute their usual dairy milk with one of these options.

However, they are not suitable for everyone.

Some people might be allergic to these ingredients, with soya being one of the most common food allergens.

For this reason, it is important to keep in mind any other health issues you may have, such as allergies or gastrointestinal problems, when selecting a dairy substitute.

There are also lactose-free dairy products that you can buy at many larger grocery stores.

These might be a better alternative for you if you are allergic to the main ingredients in dairy alternatives (like soya or hazelnuts), or if you prefer the taste of dairy milk.

Lactose-free milk is usually made by first filtering the milk to remove some of the lactose. After this, the lactase enzyme is added, to aid the digestion of lactose.

However, lactose-free milk is not suitable for anyone with a milk allergy, as it is still made from dairy.

How can I get a test for lactose intolerance?

If you are experiencing symptoms that you suspect are due to lactose intolerance, the first step is to discuss your symptoms with your physician, who will be able to offer advice and guidance on testing and treatment.

Testing for lactose intolerance can include:

  • hydrogen breath testing, conducted by measuring the level of hydrogen in your breath over several hours after consuming an oral solution of lactose
  • stool acidity testing, which measures the acidity of your stools (feces), usually after dairy has been consumed
  • genetic testing using a DNA sample

An AlphaBiolabs Genetic Lactose Intolerance Test uses a cheek swab DNA sample to assess the likelihood of a person having primary lactose intolerance.

This type of lactose intolerance is hereditary, making genetic testing a useful tool for determining whether you are likely to have primary lactose intolerance.

You have a higher chance of having primary lactose intolerance if you have a first-degree relative (parent, child, sibling) with the condition.

Genetic Lactose Intolerance Testing

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Liz Wood AlphaBiolabs

Liz Wood

Health Testing Specialist at at AlphaBiolabs
Liz joined AlphaBiolabs in 2021 as a Health Testing Specialist. As well as overseeing a range of health tests, she is also the lead on several validation projects for the company’s latest health test offerings. During her time at AlphaBiolabs, Liz has played an active role in the validation of the company’s Genetic Lactose Intolerance Test and Genetic Celiac Disease Test. An advocate for preventative healthcare, Liz’s main scientific interests center around human disease and reproductive health. Her qualifications include a BS in Biology and an MS in Biology of Health and Disease.

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