Is Dairy Causing Your Gut Issues? (Part 1)
Part 1 - lactose intolerance and ibs
Dairy is one of the most prevalent dietary triggers in the world. Its complex composition may be to blame for the digestive complaints that are commonly attributed to its consumption. I’m here to clear up the air (shall I say the “dairy air”) to help you figure out if eliminating lactose and/or cow’s milk and dairy from your diet is the right option for you – and more importantly, your gut!
First things first. Let’s look at the multiple parts that make up cow’s milk.
Lactose
Lactose is the primary sugar found in cow’s milk and other dairy products. It is known as a disaccharide. This means it is two sugars joined together (galactose and glucose). The digestive tract needs to break these sugars apart in order to absorb and use them as energy. However, many people are deficient in the enzyme lactase which is responsible for this process. This deficiency is what causes lactose intolerance (more on this in a minute!).
Milk proteins
At least 20 different proteins have been identified in cow’s milk. Casein is the most common protein (about 85%) followed by whey. About eight of these twenty proteins have been identified as allergens. This includes the whey proteins alpha-lactalbumin, beta-lactoglobulin, bovine serum albumin (BSA), and lactoferrin, as well as four different caseins. The increased number of susceptible proteins makes cow’s milk a likely candidate for one to develop an allergy to.
In addition to potential allergens, casein is a particularly difficult protein to break down because it is not water soluble like whey. In fact, casein is so strong and sticky that it is often used as a binding agent in glue for things like postage stamps and books. If it’s sticky enough to act as glue, imagine what it does in your gut?! (Casein also has a molecular structure similar to gluten, so if you suffer from celiac, gluten intolerance or sensitivity, you may find that casein gives you trouble as well.)
Milk fats
Milk fat is made up primarily of triglycerides (97-98%) which includes short-, medium-, and long-chain fatty acids. Of these fats, it is 65% saturated, 32% monounsaturated, and the remaining is polyunsaturated. High fat diets can trigger IBS symptoms and constipation, so intake and tolerance should be watched on an individual level.
As a food substance, the complexity of cow’s milk and dairy make it a perfect gastrointestinal bully when it comes to the digestion and breakdown of the different components. Let’s look at the most common dairy-related issues. In this part, we’ll look at lactose intolerance. (Stay tuned for more on cow’s milk allergy in Part 2 of this post.)
Lactose Intolerance
What Is It?
As mentioned above, lactose intolerance occurs when the body does not produce enough of the enzyme lactase. As infants, our body produces lactase in the small intestine. This helps infants digest and absorb nutrients from breast milk. However, as infants outgrow the need to nurse, they start to lose the ability to produce lactase. By about age 4, most of our lactase production is minimal or absent. In fact, most of the world’s adult population does not have the ability to produce lactase in the small intestines. Some ethnicities are affected more than others, and lactose intolerance may be more prevalent in individuals of Asian, African, Hispanic, and Indigenous origins.
Symptoms of Lactose Intolerance
The body is unable to break down lactose into its smaller parts in the small intestine; therefore, it reaches the colon fully intact. The colon is full of bacteria that love to feast on sugar molecules. As the bacteria break down the lactose for energy, the milk sugar ferments and produces large amounts of methane, carbon dioxide, and hydrogen gases causing gas and abdominal discomfort. Lactose and its byproducts may also cause the gut to retain water, resulting in cramping and urgent diarrhea.
Symptoms can range from mild to severe. The amount of lactose needed to cause symptoms is also variable due to individual differences. People who continue to consume lactose despite an intolerance may also experience fatigue and a predisposition to recurrent infections such as colds or bronchitis.
It’s important to remember that some individuals may still be able to produce small amounts of lactase depending on age, genetics, and health status. However, if they consume more lactose than the body is able to digest, this results in symptoms of lactose intolerance described above.
How It Is Diagnosed
Lactose intolerance can be diagnosed through a lactose hydrogen breath test ordered by your doctor. During this test, you drink a solution containing lactose and the amount of hydrogen gas you exhale is measured to determine if you are intolerant.
Although there is a significant amount of evidence to support that individuals with IBS commonly report milk intolerance, there is no conclusive evidence to support a link between IBS and lactose intolerance. However, there is emerging evidence that raises questions about other components found in whole cow’s milk, such as proteins, that may contribute to symptoms associated with IBS and constipation. This will be discussed in Part 2 of this post.
Living with Lactose Intolerance
If you are diagnosed with lactose intolerance, this doesn’t necessarily mean you need to remove cow’s milk and dairy products from your diet. Although, many people may choose to do so. Individuals may have varying tolerances for lactose depending on the amount of lactase their small intestines produce (small amounts versus none). Some experimentation will likely be required to determine your individual tolerance for dairy foods.
One might choose to first experiment with lower lactose foods while avoiding high lactose foods. (See table below.)
Some of the products listed in the low lactose category still contain small amounts of lactose, and sensitive individuals may have difficulty eating any amount. It really comes down to experimenting and finding what works for you. For example, it is possible you may be able to tolerate the lactose in a tablespoon of grated Parmesan, but eating yogurt might have you running to the bathroom in a hurry.
In addition to low lactose foods, there are also a number of lactase enzyme supplements available that help with the digestion of dairy foods and prevent symptoms of lactose intolerance. These supplements are taken with the first few bites (or sips) of your dairy-containing food (or beverage).
If you have been diagnosed with lactose intolerance but you still experience unwanted symptoms (digestive or otherwise) when you consume low-lactose dairy foods, there are two possibilities. Either your body does not produce any lactase, and therefore, you cannot tolerate any amount of lactose; or, you are reacting to something else in the dairy.
This brings us to cow’s milk allergy. I will cover in Part 2 of this post. Stay tuned!
Resources
“The Resourceful Mother’s Secrets to Healthy Kids” by Meredith Deasley
“The Encyclopedia of Healing Foods” by Michael Murray
“One Food Is Another’s Poison” by David W. Rowland
Lactose Maldigestion, Malabsorption, and Intolerance: A Comprehensive Review with a Focus on Current Management and Future Perspectives – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265758/
Lactose Intolerance Among Different Ethnic Groups – https://catalog.dairymanagement-west.com/wp-content/uploads/Lactose-Intolerance-Among-Different-Ethnic-Groups.pdf
Whole Cow’s Milk but Not Lactose Can Induce Symptoms in Patients with Self-Reported Milk Intolerance: Evidence of Cow’s Milk Sensitivity in Adults (PDF) – https://www.mdpi.com/2072-6643/13/11/3833
Cow's milk proteins in human milk – https://pubmed.ncbi.nlm.nih.gov/23158513/
Is There a Correlation Between Irritable Bowel Syndrome and Lactose Intolerance? - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7032600/#:~:text=They%20found%20that%20the%20risk,hydrogen%20breath%20testing%20were%20not
