Podcast Episode 124 Transcript – Lactose Intolerance

Cartoon illustration of Aidan Muir and Leah Higl for the Ideal Nutrition podcast.


and welcome to the Ideal Nutrition Podcast. I’m Leah Higl and I’m here with my co -host Aidan muir. And in today’s episode, we’ll be talking about lactose intolerance. We’ll be including what it is, its mechanisms, how to test for it, and also how to manage lactose intolerance.

So starting with a little bit of background, approximately 65 % of the world’s population are to some degree lactose intolerant. That does sound ridiculously high when you say it like that, like 65 % low, so like most of the world is lactose intolerant. But that is based on one particular stat, like one number. There are quite a few stats and numbers that are thrown around. But regardless of where you’re pulling the statistic from, the prevalence does still seem quite high.

I think a big thing to point out here is the spectrum of lactose intolerance. There’s definitely different levels to it. So someone who is very mildly lactose intolerant is likely not to identify themselves specifically as lactose intolerant. So technically they fit within that 65 % number, but maybe they just don’t self identify with that particular label.

And a lot of people just don’t want to identify with lactose intolerance for whatever reason. They might say they’re like I just don’t go that well with dairy or you know other things that are not specific to the lactose intolerance label. But nonetheless whilst the severity can differ a lot between people it does appear that many of us do have a sensitivity to lactose in some way shape or form.


Yeah, one of the reasons why I think it’s interesting looking at the percentage being so high is say you fell into the camp of thinking that you don’t go well with dairy, but you’re not necessarily lactose intolerant, because if you were lactose intolerant, it’s easier to manage. Like there’s some forms of dairy that you can have, some that you can’t. You now know what is likely to cause triggers, what’s not.

That’s kind of what we’re going to talk through, but the starting point is we’re going to talk through the mechanism of action. And there’s a lot of reasons why we’re going to go through this, but I think it helps understand everything else we’re going to talk about. So basically the main mechanism of action is that in most, not all, but the vast majority of cases of lactose intolerance, there is an insufficient amount of the lactase enzyme. In some cases, there’s borderline existent amounts. In other cases, there is a decent amount, but it’s just not enough to get the job done.

Lactase is what breaks down lactose and it does this in the small intestine. So let’s say you drank milk, it goes into the, it goes to your stomach, then it goes into the small intestine and then lactase is designed to break down lactose. If it doesn’t get broken down there, because there’s not enough lactase to get the job done, then it goes into the large intestine.

And we have bacteria in the large intestine that can also feed on lactose. So that can help to a certain degree too, but once again, maybe it doesn’t get the job done. Or another issue potentially is that it can consume the lactose but produce a bit of gas in the process of that, which could also cause bloating and gas as well. So it’s not a perfect solution either.

The reason why I talk through that is because it tells you how symptoms occur. Symptoms occur because the lactose is not digested. It’s going through the body undigested and it’s either producing gas or bloating, or it’s going through really quickly, attracting water in the process and that’s what causes diarrhea as well. That’s the mechanism. The reason why I go through that is just because it’s telling you what it’s not in the same time. It’s not an autoimmune response or anything like that.

In an autoimmune condition, for example, coeliac disease, somebody could have weight, they could have gluten, and the body starts attacking itself, and that’s what produces symptoms. In lactose intolerance, it’s actually just the lactose going through undigested, which causes symptoms. That matters heaps because dose is now very important.

In coeliac disease, obviously dose still matters, but you would want to avoid even trace amounts of gluten, because that could trigger symptoms. even other negative things, even if you’re not experiencing noticeable symptoms.

With lactose intolerance, very different thing. If you had the tiniest amount of lactose go through and it went through undigested, nothing would go wrong. If you had a large amount go through, a lot of things would go wrong. That therefore means if you have a small, small, small amount of lactose, it physically can’t be causing major symptoms, even if you had no lactase at all, which is a very important thing, which we’ll come back with stuff we’ll talk about later.


Providing a bit more context to dosage specifically. So most people with lactose intolerance can have around three grams of lactose in one sitting without symptoms. So that’s most people, obviously not everybody, but usually that’s kind of a pretty safe number and then providing context to that.

This may not be super podcast friendly content, but I think for the purpose of this, we have to provide some context of what lactose content is in dairy products generally. So for one cup of milk, we’re looking at around 12 grams of lactose. For something like 100 grams of a soft cheese, like cottage cheese, for example, we’re looking around three to four grams of lactose. In something like yogurt, it really is like brand dependent but around five to ten grams or 170 grams of yogurt. Ice cream 50 grams of ice cream around three grams of lactose. And then things like hard cheeses are actually quite naturally low in lactose. So that could be as little as 0.1 gram of lactose per 40 grams of hard cheese.

So lactose content in dairy products can vary quite drastically, which is why you might find that you get symptoms from some dairy products, but not other dairy products. Generally, research does indicate that often 12 grams of lactose in one sitting doesn’t cause symptoms, but I think in practice, that’s like a pretty high number. Like I think a lot of people with lactose intolerance, at least people that identify with that are going to react to like a whole 250 mils of like regular dairy milk.

So I would say the three gram of lactose number is probably a lot more accurate for most people that they could potentially get away with, but heading above that, there may be symptoms that start to become involved.

Another thing to mention here is just some products like your Yo -Pro, Chobani Fit, your Rokeby Farms smoothies, So these are all Australian based products. They’re all dairy based products, but they are low in lactose due to containing the lactase enzyme. So they’re even though naturally without the lactase enzyme, they could be quite high lactose containing foods. They’re unlikely to cause symptoms because they have that lactase enzyme involved as well.


Doubling down on some of those points, that three gram number is the number that we’ve chosen because it’s the number that’s low enough that almost nobody will get symptoms from. The issue with that kind of 12 gram number, as you mentioned, is that almost everybody who identifies as having lactose intolerance will probably get symptoms from that.

How did they come to that number in research? There’s obviously a few ways. One is that when we go back to that first number of 65 % of the population, I’d wager that the groups that they use in there kind of aligned with that, where it’s like there’s a lot of people who have better tolerance but would still be classified as lactose intolerant.

And the other thing is, and this is something worth interpreting in all studies that are looking at symptoms like this, is what presentation of people are in. Are they in a fasted state? And if they’re in a fasted state, that means they have had no exposure to other triggers in that day.

For example, there’s research on sugar alcohols, such as maltitol, showing that it takes like 25 to 50 grams to get noticeable symptoms in a lot of people. But then you see a lot of people in the real world getting symptoms from like, 5 grams. And is that because of sample size issues? Is that because people often have multiple intolerances and multiple triggers and they’re exposing themselves to multiple things, which is why I go with the three gram number because it’s like, if I give this advice to people and then people action it, there’s two outcomes.

One, the majority of people will not get symptoms and they’ll be like, Aidan was right. Or two, if somebody happened to be super sensitive, they’re not gonna have a horrific outcome most likely. This number is also low enough that if you did have a horrific outcome, it’s not due to lactose, it’s probably due to other things, which was why I went through the mechanism as well, because now it’s only three grams of something going through undigested.

Which then brings us on to other points like how you touched on how hard cheese has almost no lactose. So like we’ve got like cheddar, mozzarella, Swiss, they all fall into this category. They have almost no lactose and then cream has almost no lactose. One little hack for kind of thinking this through is that lactose is a sugar and sugar is a carbohydrate.

I’m not trying to oversimplify it, but when you think about it like that, anything that is low carb by definition will be low lactose. If I’ve said you can have at least three grams of lactose in a sitting without major symptoms or anything like that. Cream is pretty much exclusively fat. Hard cheese is fat and protein and it has almost no carbs. Therefore, because it is so low carb, it is also so lactose.

It’s easier to tell with certain things that don’t have added sugar. Harder to tell with something like ice cream, because it’s like when you’re looking at the sugar content, it’s not all lactose that will have added sugar as well. But it’s something that you can tell for something that’s super low carb, like by definition, this must be low lactose, which could then lead to being like hang on, I’ve had creaming got symptoms or I’ve had hard cheese and I’ve gotten symptoms. There’s many explanations for that.

Lactose intolerance is just one thing. It’s just one intolerance. What if you had intolerances to another component of dairy? What if another food you had in that caused symptoms? For example, if you had pizza and it had like garlic, onion and a bunch of like FODMAPS, for example, wheat. Is it the cheese or was it other things?

What if you just had symptoms for other reasons that day. There’s so many things that can be potential explanations. But one of the reasons why I highlight the lactose content and also the mechanism is for something like cream or hard cheese, that’s not really an opinion of mine that’s just being like, this is low lactose. Like it can’t be the reason in that case.


Yeah, classic, like my partner has lactose intolerance and he’ll eat like a whole pizza, a garlic bread, like just an insane amount of food and be like, it was the dairy. I don’t think it was the dairy. Yeah.


Which brings us to like, how do you test for this? How do you come to a conclusion that you have lactose intolerance? Back in the day, I actually don’t even think this is a test that they do anymore, but you could get a hydrogen breath test. Like you go to see a GP, they do a hydrogen breath test, which basically is measuring how much lactase you have. And they’d identify if you have a lactase deficiency, which would identify lactose intolerance.

One minor issue with that is there are cases where people would technically fall into the category of having lactose intolerance, but then they wouldn’t really get symptoms. It’s like, are you intolerant to something if you never get symptoms? It doesn’t have perfect accuracy.

So the way to test this, and a lot of times we’re against self-diagnosing stuff, but the actual way to test this is pretty simple. Have one or more cups of lactose -containing milk. Often the gold standard is like 500, but if you’re like a 500 ml, but if you’re pretty convinced you have lactose intolerance, I probably wouldn’t. Two cups of milk in one go. Probably a pretty bad day. And then the next day, or once symptoms have clearly settled down, have lactose free milk.

Feel free to repeat that experiment multiple times to 100 % confirm it. Because there is always a very, very, very small chance that you get symptoms for other reasons as well, right? But if you do that experiment and you get no symptoms with the lactose -free milk, lactose intolerance is clearly the problem.

As I said though, it’s still possible to have multiple intolerances. Like you could have issues with lactose and then issues with other things with dairy, and you might still get symptoms from the lactose -free milk. But in that case, then none of this would matter anyway, because you still couldn’t have it either way.


Totally. And now we’ll talk through strategies to improve tolerance for lactose intolerance. So outside of just avoiding lactose or minimizing lactose, there are a couple of things that you can do to manage symptoms. The first is a nice little easy hack and that is taking your lactase enzyme alongside dairy containing products, lactose containing products.

The main one in Australia that is available is called Lacteze and you can take this prior to eating foods containing lactose and it’s just going to make up for that lactase enzyme deficiency that you have and help you break down those foods without any symptoms. And I love recommending this to clients, especially for like eating out and whatnot where you don’t have too much control over, you know, what you’re eating or, you know, you just want to eat some lactose. Like just chuck this alongside it and it’s going to make things feel a lot better.

Other things that you can do to help with the management of lactose intolerance is eating lactose alongside other foods. Specifically, fiber and fat. So both fiber and fat slow digestion down. So the food and just generally the lactose is going to take longer to go through the digestive tract, therefore giving your body longer to process it.

So a good example would be if you had some soft cheese, like let’s say some cottage cheese on some high fiber bread with some vegetables and some avocado and it was part of a whole meal, you’re probably going to be able to tolerate the same amount of cottage cheese in that than if you were to have the cottage cheese in isolation.


Yeah, 100%. Even just slowing down, like because it slows down, the lactose enzyme has more time to get the job done. So assuming you have some, it will get the job done more easily. Obviously, you can’t take that to an extreme. But if you’re on, if you’re having something that you’re on the border of being able to tolerate, this will definitely help.

Another thing to talk about with this is building slash retaining tolerance. One thing a lot of people notice is if they stop consuming lactose completely, their tolerance typically gets worse. A simple explanation for this is because the bacteria in the large intestine that feeds on lactose can die off if it doesn’t have that food coming in.

I’ve heard anecdotally from quite a few people being like, I had lactose intolerance, but then I got rid of it by just having lactose containing foods. That is a possibility. You can build tolerance by having it frequently, often in relatively small amounts. The gold standard advice to people with lactose intolerance is to not completely stop having it and to have small amounts occasionally. For example, small amounts for yogurt or whatever.

The obvious issue with this is you can only build your capacity so far. You can only build it up so much. For example, if you prior to identifying the over lactose intolerance, had the equivalent of one cup of milk per day, then you identified it and then you stopped having lactose containing foods, then you learned this and you’re like, I’m gonna build up my tolerance.

If you were getting symptoms when you’re having one cup of milk per day, there’s almost a 0 % chance that you can build up to having one cup of milk and not having this issue because you had this issue when you had been having that regularly, the body can only adapt so far.

In some cases, people can build enough tolerance that it’s no longer an issue. But in a lot of cases, people can’t. One thing that everybody can do though is improve their individual level of tolerance.


So that has been our episode on lactose intolerance. And that was episode 124 of the Ideal Nutrition podcast. If you haven’t yet left a rating or a review, it would be greatly appreciated for you to do so. But otherwise, thanks for tuning in.