The impossibility of digesting lactose is due to the lack of lactase, enzymes produced by the mucous membrane of the small intestine able to break it down into the two monomers that make it up: glucose and galactose.
Due to this deficiency, when the intolerant subject takes significant quantities of foods containing lactose, the amount of sugar escaped from digestion recalls liquids in the intestine due to osmotic effect (diarrhea), and generates gas due to the fermentative intervention of the local bacterial flora.
Lactose is the main sugar present in milk; consequently, we find it in variable concentrations in all foods derived from it or containing it as an ingredient. The highest concentrations of lactose are found in milk, yoghurt and fermented milks, ice creams, soft cheeses and butter.
Lactose content of various foods
Food
Lactose 100 g of food
COW'S MILK POWDER (WHOLE)
35,1
COW'S MILK POWDER (LEAN)
50,5
cheese
6,0
BUFFALO MILK
4,9
WHOLE COW'S MILK
4,8
Partially SKIMMED COW'S MILK
4,9
LEAN COW'S MILK
4,9
SHEEP'S MILK
4,5
GOAT MILK
4,2
FRESH RICOTTA VACCINE
4,0
ROMAN SHEEP RICOTTA
3,2
WHOLE MILK YOGURT
3,2**
SKINNY MILK YOGURT
3,3**
BEL COUNTRY CREAM
3,2
SKINNED MILK FLAKES (cottage)
2,6-3
MILK BREAD
1,8
FRESH OR SEASONED EDAM
1,0
** The lactose contained in sour milk products is generally well tolerated
Normally, the lactose intolerant subject tolerates the consumption of hard cheeses, because they are particularly low in this sugar compared to fresh ones and dairy products. Yogurt is also tolerated by some individuals, since the lactose it contains is predigested by bacteria; in addition, the lactobacilli themselves - in particular some probiotic strains contained in various fermented milk products (Lactobacillus Acidophilus, Lactobacillus Casei, sp. rhamnosum, Lactobacillus johnsonii) - have proved useful in improving lactose intolerance.
when he consumes a liter of it all in one breath. Similarly, some lactose intolerant people tolerate yogurt well, some tolerate hard cheeses, while others are forced to eliminate even the smallest sources of lactose. category belong to subjects suffering from primary lactose intolerance, due to a congenital defect of lactase and therefore present from birth.
Individuals who are highly intolerant to lactose must also pay particular attention to "hidden" food sources. This sugar is in fact added as an excipient to various drugs and supplements, and is found - albeit in small quantities - in various food products. Among the latter we remember:
- bread and other baked goods
- processed cereals, such as corn flakes for breakfast
- Pre-cooked potatoes, soups, breakfast drinks
- Margarine
- Meat and salami
- Salad dressings
- Candies, snacks and other snacks, ice creams, chocolate, preparations for hot chocolate
- Prepare for pancakes, cookies and sweets
- Minced meat
- Soy milk does not contain lactose; however, due to the presence of other sugars typical of legumes (for example stachyose) it can sporadically reproduce the symptoms of a lactose intolerance.
To defend against "hidden" sources of lactose, it is important to carefully read the composition of the foods printed on product labels.
In the list of ingredients, in particular, it is necessary to ascertain the absence of milk and lactose, whey, rennet and milk by-products (lactic acid is not obtained from milk and is therefore suitable for consumption).
Therefore, if one of these ingredients appears on the label it means that the product contains lactose and therefore could be contraindicated.
The conditional is obviously obligatory, precisely because lactose tolerance is variable and depends on each individual.
What appears certain is that milk derivatives, but also various food products containing lactose, are important sources of nutrients.
For this reason, an important piece of advice is to identify - by trial and error - the amount of tolerable lactose, avoiding taking only lactose-free foods a priori.
If the intolerant individual wants to occasionally consume foods rich in lactose, he can take enzyme preparations based on lactase in the same meal, as a palliative.
As for calcium, in order to prevent any deficiencies, you can take delactosed milk (only if well tolerated) and increase the consumption of vegetables rich in bioavailable calcium (for example legumes, turnip greens, cabbage and broccoli).
Fish and nuts are also excellent sources of calcium.
