Lactose intolerance is one of the most common food intolerances, affecting up to 65% of the world’s adult population. (1) Many people choose to completely cut out dairy as a way to avoid the gastrointestinal symptoms that frequently come along with eating dairy foods. But is true lactose intolerance really the cause of their digestive distress, or are many people prematurely eliminating dairy because of a perceived inability to digest milk products? And is it possible to cure lactose intolerance, even as an adult?
The major reason some people can’t digest dairy products is they lack the enzyme lactase, which is necessary to break down lactose in the small intestine. It has been determined that continued genetic expression of this enzyme, known as lactase persistence, is dependent on ancestry and racial background. (2) The ability to consume dairy probably gave early herdsmen a distinct survival advantage, allowing for the spread of the gene in certain regions of the world such as northern Europe and parts of Africa; today, only about 40% of the world’s adult population maintain full lactase function following childhood. (3, 4) Lactase deficiency makes digesting dairy products more challenging for these individuals.
However, true lactose intolerance is rarely diagnosed by medical testing, and adults frequently mistake their gastrointestinal symptoms as a sign that they are unable to digest dairy products at all. Studies have shown that even diagnosed “lactose malabsorbers” are capable of consuming moderate amounts of dairy, tolerating an average 12 grams of lactose when administered in a single dose (the lactose content found in 1 cup of milk) with little to no symptoms. (5)
Why dairy is worth eating
You may be wondering why eating dairy even matters; after all, there are many examples of ancestral cultures that had no dairy in their diets and maintained superb health. However, it is believed that certain ethnicities may have had physical adaptations to their low calcium diet, and also traditionally consumed animal foods that are higher in calcium but probably not so appetizing to us Westerners, such as fish heads, bones, and skin. (6, 7) Therefore, they were able to meet their individual calcium needs without milk and dairy.
Calcium is a mineral that is difficult to get adequate amounts of in a modern Western diet without the inclusion of dairy. While the adequate levels of fat soluble vitamins A, D, and K2 reduces the amount of calcium an adult needs to maintain bone health, it can still be challenging to get enough calcium simply from leafy greens and bone-in fish. Several studies have shown that individuals with lactose intolerance have lower bone density and are at higher risk for fractures and osteoporosis, likely due to their inadequate calcium intake. (8, 9, 10) This risk is possibly exacerbated by low K2 consumption, as grass-fed dairy is one of the best sources of vitamin K2.
Pastured dairy products, in particular, are also a good source of the fat soluble vitamins A, D and K2 – which can also be difficult to obtain elsewhere in the diet. In fact, the only other significant sources of K2 are goose liver and natto, foods that aren’t typically eaten or easy to find. And, as I pointed out in a recent article, dairy is the primary source of the natural trans-fat conjugated linoleic acid (CLA), which may have anti-cancer and other beneficial properties.
By taking certain kinds of probiotics and consuming fermented dairy on a regular basis you can improve, if not eliminate, many of the symptoms of lactose intolerance that come with eating dairy.
Using probiotics to cure lactose intolerance
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. (11, 12, 13) 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.
If you plan to use yogurt and probiotics to improve your digestion of dairy products, it’s important to start slowly and build up tolerance gradually. Often, negative effects from dairy consumption come from simply eating more lactose in one sitting than one’s gut can completely metabolize. I recommend starting with probiotic supplementation first, and focusing on bifidobacterium longum, a strain that has been shown to efficiently metabolize lactose. (14)
Jarro-Dophilus, a shelf-stable probiotic that doesn’t require refrigeration, is one option. Taking prebiotics is another way of significantly increasing bifidobacterium levels; in fact, some studies suggest prebiotics are more effective than probiotics at doing this. Biotagen is the prebiotic I use in my clinic. Remember to start at a very low dose and build up slowly over time with both pre- and probiotics to avoid any unpleasant side effects.
In addition to this supplement, I suggest consuming a few spoonfuls of a high quality full-fat yogurt every day, with each meal if possible. This will introduce beneficial bacteria into your gut that are effective lactose metabolizers, and by slowly increasing the amount of yogurt you eat every day, you may be able to work up to eating two or more servings of fermented dairy every day.
If you tolerate the yogurt well, and want to try diversifying your dairy intake, my next recommendation is to start including full-fat hard cheeses (raw if possible); these cheeses are great sources of calcium and vitamin K2 and are very low in lactose. One ounce of hard cheese contains about a third of the recommended intake of calcium, and gouda is the best source of vitamin K2 of all cheeses. (15) These hard cheeses are extremely low in lactose, and make a nutrient-dense addition to a whole foods diet. As you become more tolerant of dairy products, you can try higher lactose items such as soft cheeses, cream, and even fluid milk. Just remember to stick to the full fat and grass-fed versions as often as possible.
Of course, another option to try is raw milk. Anecdotal evidence from raw milk drinkers around the country suggests that many people who cannot tolerate pasteurized milk have no trouble drinking raw milk. (16) Research conducted on this theory, however, indicates that truly lactose intolerant individuals do not experience any benefit from drinking raw milk over pasteurized milk. (17)
The best way to figure out which dairy products work for you and your digestive system is simply to try them yourself. By taking the time to introduce lactose fermenting bacteria through probiotics and high quality yogurt, you may find your lactose intolerance symptoms decreasing over time. Of course, if you’d rather eat fish heads to get your calcium, feel free to skip the dairy!