Dairy provides an optimal macronutrient ratio of carbohydrate, fat and insulinogenic proteins to promote human growth and development.
In addition to providing a dense source of calories, dairy yields minerals, vitamins and growth of beneficial gut bacteria. However, the ability to digest components within dairy (lactose, casein, whey) may change due to hereditary predisposition or health factors, such as gut-constitution.
Below are commonly asked questions around digestion of dairy components and possible sensitivities or allergy responses.
When I eat dairy, I feel bloated and my stomach hurts. What gives?
As a general recommendation, if something causes your stomach to hurt, you probably should avoid it, or muster up a plan for gut-healing, then reintroduce it at a later date.
In regard to dairy, there are three components of dairy that may be causing these symptoms: the milk sugar lactose, or one of two proteins, whey or casein.
Of these three dairy components, a likely cause is lactose intolerance, or the inability to digest lactose.
What exactly is lactose? And lactase?
Lactose is a disaccharide sugar (two sugar molecules: one galactose molecule and one glucose molecule). The villi in the small intestine secrete an enzyme called lactase.
Lactase cleaves the lactose disaccharide into two separate sugar molecules, galactose and glucose. If you are not producing the enzyme lactase, you are not breaking down the sugar molecule lactose.
If you’re not breaking down lactose, the undigested lactose may move to the large intestine, where the large intestine’s bacterium ferments the lactose, causing gas, bloating and diarrhea.
Can I take a test to determine if I am lactose intolerant?
Yes, a common test is the hydrogen breath test. Here’s how it works: a person consumes a lactose powder, and then at timed intervals over a few hours, the person blows into a device which measures the amount of hydrogen or methane in the breath.
If the enzyme lactase in the small intestine properly breaks down the digested lactose, no hydrogen or methane will be produced because the lactose never reaches the large intestine. If the lactose molecules pass through the small intestine undigested, and are consumed by the bacteria in the large intestine (bad thing!); the bacteria will produce hydrogen and/or methane, and the resulting gas will be recognized in the breathe.
While a test can confirm a malabsorption or allergy, acknowledging symptoms and how you feel after eating a certain food can be just as insightful.
I am slightly lactose intolerant -- I can eat small amounts of dairy, but eating too much causes bloating and digestive distress. What should I avoid? What can I eat?
Lactose makes up approximately 5% (by weight) of milk. If you’re drinking milk, you’re getting a hefty dose of lactose. However, fermented dairy (think butter, ghee, yogurt, kefir, hard cheeses) contains less lactose and may serve you better than raw dairy.
If you’re feeling adventurous, try goat dairy – it has less lactose than milk dairy.
Additionally, raw milk naturally includes the bacteria lactobacillus, among other beneficial bacteria.
If you only have a slight lactose intolerance, the lactobacillus found in raw milk may help you break down the lactose.
I’m lactose intolerant. Will I ever be able to eat dairy again?
The inability to produce lactase can be due to one of two factors: 1) genetic, or 2) impaired digestion.
In regard to genetic disposition, lactose intolerance after infancy is widespread; 65% of the human population has a reduced ability to digest lactose. On the other hand, those with a history of dependence on milk products better tolerate lactose; only 5% of northern European descents are lactose intolerant.
If you suffer from leaky gut, SIBO or impaired digestion, Chris Kresser suggests in this article that consuming probiotics and fermented dairy on a regular basis can help improve the presence of lactobacillus in the small intestine, thereby improving the presence of lactase.
Studies have shown that supplementation with probiotics, in addition to consuming yogurt that has been enhanced with certain types of bacteria, can alleviate symptoms of lactose intolerance by modifying the metabolic activity of microbiota in the colon.
These bacteria may even produce their own lactase enzyme, and consuming lactose from dairy products can promote the growth of these bacteria in the colon. Over time, these effects can lead to greater lactase content in the gut, improved lactose digestion, and eventually the elimination of intolerance symptoms.
Does butter or ghee have lactose?
Butter and ghee have a very slight amount of lactose, and should be safe to consume.
I did the lactose intolerance hydrogen test, and it indicates I’m not lactose intolerant. Could I be allergic to a protein in milk?
There are two other components in dairy that may be problematic – the two protein components, casein and whey. Of the two dairy proteins, casein is the most likely to cause an antibody response (IgE-antibodies).
80% of protein in cow’s milk is casein, 20% of protein in cow’s milk is whey.
Casein is found in cheese and in concentrated amounts in hard cheese. Casein is also found in Greek yogurt, cottage cheese, milk, yogurt, kefir, butter and casein-containing protein powders. The protein structure of casein is similar to that of the protein in gluten-containing grains, gliadin. So if you react to gluten, you may also react to casein.
Whey is the second protein that may produce an antibody response. Whey is added to processed foods and is found in ricotta cheese, milk, yogurt, kefir, butter and whey-containing protein powders.
If you can tolerate it, full-fat, organic dairy is an excellent source of calories and nutrition. Remove it, try it, then obverse your symptoms to see if dairy is right for you.