Lactose Intolerance, What, Why, When, Where and How to treat it.
For the past few weeks, I have been experimenting with implementing dairy into my diet after about 2 years of not eating it. I was so afraid of dairy and how it would make me feel. I thought that because I had a lactose intolerance, eating a drop of dairy would tear my guts up and cause lifelong damage. Because at points, that's what it felt like, but guess what my friends. As I am writing this I am eating dairy. There is hope!
I was uneducated on the topic. I got fed up with not really knowing what was going on with my body when I ate dairy, so I decided one day that I was going to learn about it. During the process I found that there wasn't really that much information out there in forms that I could understand, which brings me to today's post.. I am going to teach you all about Lactose intolerance.
Lactose intolerance is the most common food intolerance in the world. But is rare in infants as they can easily digest lactose in breastmilk. Numbers skyrocket with age, and your genetic ethnic background is also a predictor of your risk of developing it, which is so interesting!
We are going to explore the signs and symptoms of lactose intolerance and then go on to explain how it is diagnosed and how it can be managed. The good news is that it rarely means the exclusion of dairy products.
Lactose intolerance is a digestive disorder caused by the inability to digest lactose, the main carbohydrate and sugar in dairy products. It's what's called a disaccharide, this basically means its a sugar molecule in two. Lactose is actually two sugar molecules joined together, a glucose molecule and a galactose molecule which combine to make lactose.
Lactose intolerance is a condition where symptoms are directly linked to the malabsorption of lactose which can be caused by either a reduced or absence of activity of the digestive enzyme lactase. Lactase is found on the surface of the intestinal lining in our guts. It is what's needed to digest the lactose sugar into its single sugar units of glucose and galactose.
An important note, lactose intolerance is different from a dairy allergy. They are two different conditions caused by dairy intake. Lactose intolerance is a carbohydrate intolerance caused by the body's inability to digest lactose, whereas cow's milk allergy is an immune reaction to the proteins found in milk.
The degree of symptoms someone experiences with lactose intolerance depends on several factors. Said factors include the amount of the lactase enzyme present in the intestinal wall, the intestinal microbiome flora, the amount of lactose consumed, and the motility of the gastrointestinal tract.
Lactose intolerance around the world:
Worldwide lactose intolerance cases are put at around 60 percent of the population, but the distribution is very uneven. In countries like Australia and the USA, it is closer to 50 percent, while in Asia it is 70 percent. And in Africa, it’s close to 100 percent. There are clear ethnic differences where prevalence rates drop down to about 15 percent in people from a Caucasian background. In Scandinavian countries, it is barely registered with a prevalence rate of just 2 percent.
Several theories have been put forward to explain the cause of these differences in the ability to digest lactose. The main one is based on the observation that dairy products played an important role in the diet in Northern Europe over the centuries. Therefore, it provided a natural selection of people capable of digesting lactose. More recent migration rates still reflect this pattern.
All these stats don’t apply to infants though. From the eighth week of gestation in the mum's belly, the activity of lactase can be detected on the mucosal surface of the intestine and this activity progressively increases until it reaches its maximum peak at the time of birth. So the newborn is all set to digest lactose in breastmilk.
It is the decline of lactase activity post-weaning and into adulthood that is the issue that explains most cases of lactose intolerance and this is called primary lactose intolerance. In primary lactose intolerance, lactase production falls off sharply by adulthood, making milk products difficult to digest.
If you can’t digest lactose, then it has only one place to go and that’s into your large intestine where it makes a fab fuel source for your gut bacteria. Of course, the fermenting action means the production of metabolic by-products and gasses, all compounded by excess water being drawn into the GastroIntestinal tract. Symptoms of lactose intolerance generally appear when the percentage of lactase activity is less than 50 percent in an individual.
The symptoms one with lactose intolerance may experience include; Abdominal pain, bloating, diarrhea, rumbling or gurgling noises, nausea and vomiting. On average, the symptom onset occurs about one hour after consuming foods containing lactose.
But not everyone with lactose intolerance will develop symptoms of the same intensity. This is because of the varying amounts of gas produced by each person (indivuals bacterial flora make up will impact this).
Diarrhea can be explained by the production of fermentation by-products called SCFAs which acidify the colon and draw in water into the colon. Which has to be excreted, in number 3’s.
Symptoms of lactose intolerance though can occur outside of the gut with memory issues, headaches, musculoskeletal (muscles, bones, joints and tissues) pains, heart rhythm disorders, depression, anxiety, ulcers, disturbances of the menstrual cycle and even eczema have been linked to it.
These disorders could be caused by the excessive production of chemical substances such as acetone, acetaldehyde, ethanol, peptides, and others which are formed in the course of maldigestion and malabsorption of lactose.
So how is lactose intolerance diagnosed? One way, at least in determining if someone has a genetic predisposition, is based on a genetic test to look at unique DNA changes, of the gene coding for the lactase enzyme. Such a test is useful to distinguish between primary and secondary lactose intolerance.
Primary lactose intolerance occurs as the activity of lactase declines as people age. Secondary lactose intolerance is due to injury to the small intestine as a result of infection, coeliac disease, inflammatory bowel disease, or other diseases.
Then there is also the hydrogen breath test, which is the most frequently used method to diagnose lactose intolerance. The test exploits the phenomenon where the fermentation of lactose by the microbial flora produces gasses, including hydrogen. The test involves the measurement of exhaled hydrogen after taking on a load of about 50 grams of lactose.
Other methods for diagnosing lactose intolerance include direct measurement of lactase activity done after a biopsy of the intestinal mucosa. This test is done through endoscopy, and is pretty invasive.
Finally, there is a blood test that looks at the change in glucose levels over 2 hours after taking on a 50-gram load of lactose when fasting. If the lactose isn’t being digested (remember that lactose is made up of Glucose Galactose joined together, when digested properly they are broken apart and liberated into the bloodstream), then little to no glucose will be liberated so blood Glucose levels won’t change much. It’s an easy test to do, however it has low specificity for diagnosing intolerance.
Now, What are the best ways to manage lactose intolerance? Excluding all lactose seems like most obvious, but not everyone needs to go to this far as dairy products can be (for those who wish to consume it) an important source of calcium, proteins and minerals if someone otherwise has no need or desire to cut back on dairy foods.
Many people with lactose intolerance can tolerate up to 15 grams of lactose per day without any obvious symptoms. That’s equivalent to a glass of milk. And it can be better to consider the full-fat variety as the extra fat can slow the journey of the milk through the intestines which would allow lactase more time to digest the lactose.
When looking at yogurt, then 200 mL will contain about 10 grams of lactose, though this can decline more over time as the bacteria slowly eat up the lactose in the fermentation process of the milk to yogurt.
The amount of lactose in a serve of most cheeses is well under 2 grams and in the harder and matured cheeses like cheddar, Swiss and brie contain tiny amounts so there is no need to be cutting these foods out altogether. Here, it is best to trial over time what works for you. Spreading out lactose-containing foods over the day is also another good strategy.
Then there is the use of external lactase enzyme supplements as pills or liquids that pre-digest lactose. Furthermore, there are products available which I personally just tried this morning- lactose free yogurt, that have the lactase enzyme mixed into the product itself. This allows for the lactose to not have as much of a negative effect on the body as the lactase- this is how I see it, stay with me here.. There's lactose in the dairy product, the lactase then comes in and eats the lactose, and then the lactose says bye bye, and your gut stays happy because it doesn't have to work as hard to digest the lactose, thanks to the lactase enzyme mixed into the product.
You could also try alternative milk options, but do your research into how each of them compare. NOTE: always do your own research and talk to a healthcare professional or someone who has knowledge of the topic, before you start blindly making any changes to your health. Though likely with good intent, you may end up doing more damage than good to your health. Or you could teach yourself, but make sure you approach your research with the understanding that bias may be playing a role in the information you come across.
Then there is the option to treating lactose intolerance with probiotics which love a meal of lactose. Several studies have been conducted and in some cases, both a reduction in the amount of exhaled hydrogen and an improvement in symptoms have been seen. But the research is very mixed and it was the finding of a 2019 systematic review which is linked in the references show notes, which looked at 15 RCTs and 8 different species of bacteria. Overall, there was a benefit, but it was not a uniform one.
Common strains used included Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus rhamnosus, Lactobacillus bulgaricus, Bifidobacterium longum, Bifidobacterium bifidum and Streptococcus thermophilus so these would be the ones to look out for if you want to do a bit of self-experimentation.
There is no standard treatment for lactose intolerance and this is a clear example where personalized advice and some degree of self-experimentation is supported.
I hope you learnt a bit about lactose intolerance. Remember to do your own research, and trust your intuition when it comes to implementing any health advice.
All the love in the widest universe,
Minty and Winty.
References:
Thinking nutrition podcast episode on Lactose Intolerance symptoms, diagnosis and treatments:
BiteMe nutrition podcast episode on Lactose Intolerance:
