Lactose: should it be avoided to digest better?
It is difficult today to know what proportion of French people are lactose intolerant: between self-diagnosis, pressure from the dairy lobby, north-south geographical disparities (where food cultures differ) and low proportion of those diagnosed, it is difficult to quantify the phenomenon. Some published figures speak of 15 to 20% of the French population. But what is lactose? Why is it difficult to digest? How is lactose intolerance and what to do?
What is lactose?
Lactose is acarbohydratenaturally present in themilk of mammals: cow, sheep, goat (to a lesser extent), but also breast milk. It is a simple sugar (disaccharide molecule, composed of aglucosemolecule and agalactose molecule) with relatively low sweetening power. It concentrates mainly inwhey andcasein.
Where is lactose found?
Lactose is thereforefound inmilk, whether whole, semi-skimmed or skimmed. Inbutter, it is almost absent, degraded during churning. It is alsonot very present inpressed cheeses (Comté, Beaufort, Emmental, Parmesan …), fermented or matured, because draining and fermentation partially eliminate it. Finally, all fermented dairy products (kefir, ribot milk, yogurt) contain only traces, lactic ferments degrading it.
On the other hand, lactose isvery present in all products requiring the addition of milk powder,wheyorlactose for their manufacture. This is particularly the case forindustrial dairy products, even minimally processed, such as petits suisses, fresh cheeses, faisselle,cottage cheese, crème fraîche, dairy desserts or ice cream.
Other industrial food products use lactose as an additive because it can change the texture of certain foods (creamier consistency), improvetaste, or even increase the weight of the product at a lower cost. This is for example the case ofindustrial cold cuts (sausage, pâté),surimi,sauces,pastry and bakery products,biscuitsorconfectionery.
and, in addition, can have the same impact on the digestive system as lactose.
How is lactose digested?
In principle, all humans have, when they are infants, a genetic predisposition to secrete a lot of lactase, to digest the mother’s milk necessary for their growth. However,after weaning and then in adulthood, this secretion decreasesin more or less significant proportions. We observe, for example, a greater endowment among traditionally pastoral peoples – their chronic consumption of milk for millennia having had repercussions on their organism (genetic evolution).
In case of hypolactasia (about 75% of the world’s adult population), it is the intestinal bacteria that take over the digestion of lactosetag. To do this, they produce assimilable elements for the body, as well as gases (fermentation of undegraded sugar).
When can we speak of lactose intolerance?
Not all cases of hypolactasia lead to lactose intolerancetag. In some individuals, it is asymptomatic. Others suffer at most from somebloating and abdominal swelling, in case of excessive consumption of lactose. But in some people, it is proven. This is particularly the case for people in East Asia and equatorial Africa, where milk has never been traditionally consumed.
But what is lactose intolerance? The symptoms are clear :
- the first symptoms generally appear in the first hours following the ingestion of foods containing lactose;
- their intensity depends on the quantity ingested ;
- digestion leads to bloating , flatulence and belly swelling ;
- if the amount absorbed is large, lactose can give rise to more severe symptoms, such as diarrhea , abdominal cramps , headaches , even vomiting ;
- digestive disorders are systematic and unavoidable when consuming food containing lactose.
Finally, to clarify that lactose intolerance can be congenital (innate), although rare, or result from an intestinal disease, temporary or permanent. Thus, people with functional bowel disease (also called irritable bowel syndrome), celiac disease (gluten intolerance), Crohn’s disease or SIBO are more likely to also have lactose intolerance. But a simple gastroenteritis, weakening the balance of the intestinal flora and the intestinal villi can lead to temporary intolerance.
How is lactose intolerance diagnosed?
There are currently three medical tests that can diagnose lactase deficiency and, in full, lactose intolerance.
The first consists in carrying out a biopsy of the small intestine, to measure the enzymatic activity, particularly that of lactase. But this test is little used, since it is invasive.
The second consists of a breath test: the patient is administered 10 g of lactose, then the hydrogen content of the exhaled air is measured. Indeed, the undigested lactose in the small intestine will pass into the colon, where the bacteria will transform it into gas (including hydrogen). This gas will pass into the blood and reach the lungs, where it will be rejected. The breath therefore makes it possible to detect a possible lactase deficiency.
The third is blood: it consists of performing a blood glucose test after ingestion of lactose. If the blood sugar does not rise, this means that the lactose is not digested, since it has not been broken down into glucose and galactose (the two molecules that make it up). We can then establish the existence of a lactase deficiency.
How to manage your lactose intolerance?
Today there is no way to cure lactose intolerance. Thus, it is necessary to act directly on its diet.
You can also decide to adjust your diet to your lactose tolerance thresholdtag. Each individual is different: some will tolerate a small amount, others will suffer at the slightest absorption. So it’s all about experimenting and seeing what you can eat and how much.
(drink, tablets) is also an alternative. On the other hand, it must be punctual, typically when you know that you are going to eat products rich in lactose. It is a way to continue to consume “pleasure” foods, from time to time, without risking the inconveniences associated with intolerance.
) can also help, bacteria allowing better digestion of lactose. However, this recommendation is balanced by the fact that orally absorbed probiotics rarely survive the digestive process.
Finally, the long-term FODMAP dietcan be considered. Indeed lactose is classified among FODMAPs (Fermentable Oligo-, Di-, Monosaccharides and Polyols), since it is a disaccharide. On the other hand, it presupposes an eviction (at least during its first phase) of all dairy products and thus, possible deficiencies and a depletion of the intestinal microbiota. However, it is scalable and adapts to everyone’s digestive sensitivities.
Stephen Paul is the lead author and founder of My Health Sponsor. Holder of a diploma in health and well-being coaching with more than 200 articles in the field of health, he makes it a point of honor to offer advice based on reliable information, based on scientific research, and verified by health professionals.