May 2017: Q&A on lactose intolerance

Is lactose intolerance related to lifestyle or to eating habits?

lactose-intolerance-lifestyle

No, lactose intolerance is not related to lifestyle but can be related to eating habits and to individual variability. Some individuals can digest lactose, while others cannot.

Indeed, the ability to digest lactose (a type of sugar naturally found in milk and dairy products) is due to the persistence of lactase (an enzyme) in the intestine, where lactose is transformed into glucose and galactose, for energy and various functions. Lactase activity reaches its maximum at birth and slowly declines after weaning. Lactase activity may persist in some populations where dairy products are consumed into adulthood, especially Caucasians from Northern Europe (Scandinavia, the British Islands and Germany) and specific communities in Asia, Africa, South America, Southern Europe and Australia.

Lactose intolerance can occur in individuals with lactose maldigestion, the reduced capacity to digest lactose, which consumes large amounts of lactose in one intake (>12 g) or during the day (>24 g) apart from meals.

Lactose intolerance is a type of lactose maldigestion, which results in one or more of the following symptoms: bloating, diarrhea, and flatulence.

Similar symptoms of lactose intolerance can be observed after consumption of some short-chain carbohydrates, the FODMAP (Fermentable, Oligo-, Di-, Mono-saccharides And Polyols), which are poorly absorbed in the small intestine.

Lactose maldigesters, including lactose intolerants, can consume foods containing lactose, such as dairy products, in small amounts. Yogurt consumption is particularly encouraged since yogurt contains live ferments, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, which have been officially acknowledged to improve digestion of lactose in yogurt, in individuals with lactose maldigestion.

For more information about lactose-free food, please go to question 19.

Sources:

Adolfsson et al. Am J Clin Nutr 2004;80:245-56.

Deng et al. Nutrients 2015;7:8020-35.

Eadala et al. Aliment Pharmacol Ther 2011;34:735-46.

Efsa Panel on Dietetic Products N, Allergies. Scientific Opinion on lactose thresholds in lactose intolerance and galactosaemia. EFSA Journal 2010;8:n/a-n/a.

Efsa Panel on Dietetic Products N, Allergies. Scientific Opinion on the substantiation of health claims related to live yoghurt cultures and improved lactose digestion (ID 1143, 2976) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010;8:n/a-n/a.

Ledochowski et al. Dig Dis Sci 1998;43:2513-7.

Misselwitz et al. United European Gastroenterol J 2013;1:151-9.

Suarez et al. N Engl J Med 1995;333:1-4.

Szilagyi et al. Can J Gastroenterol Hepatol 2015;29:149-56.

Yang et al. Aliment Pharmacol Ther 2014;39:302-11.

YINI-WGO-Lactose-Intolerance