Everything you need to know about lactose intolerance
If dairy causes you some tummy troubles, you’re not alone: milk is considered a Priority Allergen in Canada and the vast majority of humans (over 70%!) also have some degree of lactose intolerance. As a registered dietitian who has long been interested in gut health nutrition (I even wrote an entire cookbook on food and the gut), I’ve seen many clients with similar concerns. In this article, we’ll talk about what lactose intolerance actually is, how it is different from dairy allergy and what to do if you think you’re lactose intolerant.
What is lactose intolerance?
Lactose is a sugar molecule made of two smaller sugars, glucose and galactose. Your body makes a special enzyme called lactase to break the bond between glucose and galactose so your body can absorb the smaller sugar molecules.
The lactase enzyme is made along the brush border of our gut cells; however, not everyone makes a lot of lactase. When your consumption of dairy outstrips your body’s ability to digest it, the lactase stays in the gut, traveling through the intestine until it is excreted.
Along the way though, a few things happen: because it is a sugar, it draws water to it – which can loosen up your stools. Plus, since it’s a sugar, there are a few trillion bacteria living in your gut (give or take!) that can ferment it, leading to the production of gas or perhaps even some bloating.
Types of Lactose Intolerance
There are two main types of lactose intolerance:
- Primary lactose intolerance: the body doesn’t make enough lactase enzyme to match dairy consumption, due to production decreases after childhood. This production decrease is actually genetically controlled and is thought to be non-curable.
- Secondary lactose intolerance: the body temporarily loses the ability to digest lactose due to inflammatory damage to the gut, as in celiac disease or Crohn’s disease. When the gut heals, it is thought that tolerance bounces back, but I have found that for some of my clients, it doesn’t.
It’s also worth noting that lactose is considered a FODMAP, meaning that if lactose intolerance appears to be an issue – and you suspect you might have symptoms of irritable bowel syndrome – that a full low FODMAP elimination might be in order. Worth talking to your doctor about the possibility.
Dairy allergy vs lactose intolerance
There is a lot of misunderstanding about what food allergy is and what food intolerance is…so here is the bite-sized version.
Food allergy is an immune mediated reaction (typically IgE-mediated, to get technical) to proteins in food. Food intolerance is a non-immune mediated reaction to a carbohydrate in food – in this case, the lactose in milk – although there are a few early trials questioning whether fats or different casein protein structures are causing gut symptoms.
How do I know if I am lactose intolerant?
Our memory is not always the most dependable guide, so I recommend that the best way to get to the bottom of your symptoms is by keeping a food and symptom journal. Each day for 2-3 weeks, in your phone or in a notebook, record the following:
- Exactly what you ate and the time you ate it
- Any symptoms experienced, the time you felt them, and their severity on a scale of 1-5
- Stress level for the day on a scale of 1-10
- Hours of sleep and any daily workouts or activity
When you review your record, the culprit might jump out at you immediately. True allergic reactions are usually quite rapid in onset making it easier to connect them to the meal you just ate. However, food intolerance reactions are usually more delayed in response (could be hours or days post consumption) and can be influenced by the other foods eaten along with lifestyle factors such stress. Even if this journal doesn’t clarify things for you, it can be enormously helpful for your doctor or dietitian.
Lactose intolerance symptoms
Lactose intolerance symptoms, however, tend to be a little more cut and dried. Eat the lactose, get the symptoms…it’s as simple as that! As lactose travels through the gut, it can lead to the following symptoms:
- Gas, bloating and distention
- Abdominal pain
- Diarrhea and increased urgency or bowel transit time
At the doctor’s office, they may suggest a test to determine lactose intolerance or diagnose based on their clinical evaluation. It may seem like a non-consequential issue not worth seeing a doctor about, however, because these symptoms can be connected to a more serious concern, it’s important to see your doctor should you present with these symptoms (particularly diarrhea) for more than a few days.
Probiotics for lactose intolerance
There are some probiotic bacteria that can actually make lactase enzyme. In fact, the research suggests that some bacterial strains may improve symptoms of lactose intolerance – starting with something in the lactobacillus species is probably a good start. However, be aware that I have yet to see any retail probiotics that are approved for lactose intolerance claims so be sure to do your homework when selecting a probiotic.
How to eat a low lactose diet
There are few options you can take when trying to remove lactose from your diet.
Gauging your lactose tolerance level and sticking to it
Lactose tends to be lower in fermented dairy products – and of course, smaller serving sizes will have less lactose. Everyone will have a different tolerance level for lactose, meaning that some people will be able to tolerate yogurt and cheese well, but perhaps not milk or ice cream. Or, you may be able to have small scoop of ice cream after a meal (meals often increase tolerance to lactose as opposed to eating on an empty stomach) but you can’t have milkshake in the middle of the day. Experiment with dosages (1/2 cup is a good starting dose) of fresh dairy and fermented dairy and see where that tolerance lies for you.
Taking a lactase enzyme and having your dairy whenever you want
There are also lactase enzyme supplements available to help you digest a meal that contains dairy when you want it. You can always keep them on hand for when you don’t want to – or can’t – avoid lactose.
Maintaining a low lactose diet
The next level of avoidance is to simply consume low lactose dairy products, which are widely available. You can get everything from lactose-free sour cream to milk and ice cream. Lactose-free milk tastes a bit sweeter than regular milk as the lactose molecule has been broken into glucose and galactose, which your tongue will sense.
Going dairy free: what to look for in plant-based dairy alternatives
Your fourth option is to avoid dairy, in favour of plant-based milk alternatives. As a plant-based gal myself, I’m all for it. It is quite easy to enjoy plant-based dairy alternatives, as the variety and quality has grown substantially in the last five years. If this is the route you want to take, you need to know a couple of things:
- Strive for milk alternatives with no added sugar. Some plant-based mylks can have a lot of sugar in them…which isn’t a very healthy alternative.
- Make sure your plant-based mylks have calcium – this is the main nutrient you are receiving from dairy that is harder to replace elsewhere. Most are fortified, but some aren’t.
- The other main nutrient that dairy products offer is protein…and this isn’t the case with a lot of plant-based alternatives. Some, like organic soy mylk, have protein levels that are close to dairy milk but most, like almond or cashew mylk, don’t. This is okay as long as you ensure that you are getting enough plant-based protein from other sources. Take some time reading the labels when you’re shopping and get to know what’s available as it is changing all the time!
Gut issues can be frustrating – as digestive health dietitian and someone with IBS, I know this all too well. If something in this article sparked your awareness, be sure to talk to your doctor about screening for gut issues and then make an appointment with one of our dietitians to help you create a way of eating that helps you feel good.