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Yogurt improves lactose digestion and reduces symptoms of lactose intolerance

Yogurt improves lactose digestion -YINI

For the 10th anniversary of YINI, we gathered the recent evidence-based science about yogurt and health effects in a sustainable healthy diet.

Live yogurt cultures have properties that improve digestion of lactose.

Lactose maldigestion is common in adults

Lactose is a natural sugar found in milk and other dairy products. It can be broken down in the small intestine by the enzyme lactase into glucose and galactose, two simpler sugars that are readily absorbed into the bloodstream.

After weaning, our ability to digest lactose declines because we produce less lactase. Difficulty in digesting lactose due to this normal reduction in lactase production/activity is known as lactose maldigestion.

Undigested lactose reaching the colon is broken down by the resident microbiota, resulting in the production of short-chain fatty acids (SCFAs) and gases. In most people, this maldigestion produces no noticeable symptoms.

Lactose intolerance - how does it work - YINI

When lactose maldigestion gives rise to symptoms such as bloating, cramps, diarrhoea, and flatulence, this is called lactose intolerance.

Self-diagnosis of lactose intolerance is common, but it is often incorrect and in fact very few people have confirmed clinical lactose intolerance.

People with lactose intolerance may eat moderate amounts of dairy products without experiencing significant symptoms

Dairy products are widely recognised as an important part of a healthy diet as they are a source of several nutrients. Dairy products are particularly important for providing calcium, for which it is difficult to achieve the recommended daily intake from a dairy-free diet without supplements.

It is therefore important that dairy products are part of everyone’s diet, including people with lactose maldigestion or intolerance.

People with lactose intolerance or lactose maldigestion can generally tolerate up to 12 g (~0.4 ounces) of lactose (equivalent to about one glass of milk or 240 g/~8 ounces of natural yogurt), particularly when consumed as part of a meal, with no or minor symptoms.
There is some evidence that a daily intake of 24 g (~0.8 ounces) of lactose can be tolerated if it is distributed throughout the day and consumed with other foods.

Since dairy products vary in the amount of lactose they contain, the amount of lactose ingested depends upon the type and quantity of dairy products consumed. In particular, a reduced level of lactose is found in yogurt containing the two active bacterial cultures L. delbrueckii subsp. bulgaricus and S. thermophilus.

Yogurt may improve lactose digestion

The live bacteria L. delbrueckii subsp. bulgaricus and S. thermophilus produce lactase which breaks down some of the lactose in yogurt.

  • The bacteria survive their passage through the gut and the bacterial lactase helps further with digestion of lactose in the small intestine.
  • Unlike milk, yogurt’s semi-solid state benefits lactose digestion by slowing transit through the gut.
  • Several studies show that yogurt with live active cultures may significantly enhance lactose digestion and reduce symptoms of intolerance in people with lactose maldigestion.

“Yogurt consumption is recommended by health authorities as part of a healthy balanced diet, even for people with lactose maldigestion or intolerance. In fact, yogurt containing live active cultures may improve lactose digestion and reduce symptoms of intolerance in people with lactose maldigestion.” – Professor Bob Hutkins

Yogurt improves the digestion of lactose - YINI

Yogurt is recommended by health authorities for people with lactose maldigestion

The European Food Safety Authority (EFSA) has approved the claim that yogurt improves digestion of lactose.

  • The EFSA’s conclusions were based on 13 studies showing that consumption of live cultures in yogurt improved digestion of lactose in yogurt among people with lactose maldigestion.
  • To qualify for this claim, yogurt must contain at least 108 CFU live starter bacteria (L. bulgaricus and S. thermophilus) per gram of yogurt, and therefore fresh yogurt is best. Ultra-high temperature (UHT) yogurt or yogurt labelled ‘long-life’ has been heat-treated and this process kills the beneficial bacteria.

Several medical organisations recommend that people with lactose maldigestion – including those with lactose intolerance – consume yogurt as part of a balanced diet.

“The live bacteria in yogurt survive passage through the gut. The lactase they produce breaks down some of the lactose in yogurt and this allows people suffering from lactose maldigestion/ intolerance to gain the nutritional benefits of yogurt and of other dairy products as well.” – Professor Naïma Lahbabi-Amrani

  • Rozenberg S, Body JJ, Bruyère O, et al. Effects of dairy products consumption on health: Benefits and beliefs – a commentary from the Belgian Bone Club and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases. Calcif Tissue Int. 2016;98:1–17.
  • Saviano DA, Hutkins RW. Yogurt, cultured fermented milk, and health: a systematic review. Nutr Rev. 2021;79:599–614.
  • Suchy FJ, Brannon PM, Carpenter TO, et al. NIH Consensus Development Conference Statement: lactose intolerance and health. NIH Consens State Sci Statements. 2010;27:1–27.
  • Muehlhoff E, Bennett A, McMahon D. Milk and dairy products in human nutrition. Food and Agriculture Organization of the United Nations. 2013.
  • EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). 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;8:1763.
  • EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific Opinion on lactose thresholds in lactose intolerance and galactosaemia. ESFA Journal. 2010;8:1777.
  • Lukito W, Malik SG, Surono IS, et al. From ‘lactose intolerance’ to ‘lactose nutrition’. Asia Pac J Clin Nutr. 2015;24(Suppl 1):S1–8.
  • Casellas F, Aparici A, Casaus M, et al. Subjective perception of lactose intolerance does not always indicate lactose malabsorption. Clin Gastroenterol Hepatol. 2010;8:581–6.
  • Wilt TJ, Shaukat A, Shamliyan T, et al. Lactose intolerance and health. Evid Rep Technol Assess (Full Rep). 2010;(192):1–410.
  • Savaiano DA. Lactose digestion from yogurt: mechanism and relevance. Am J Clin Nutr. 2014;99(5 Suppl):1251S–5S.
  • Bailey RK, Fileti CP, Keith J, et al. Lactose intolerance and health disparities among African Americans and Hispanic Americans: an updated consensus statement. J Natl Med Assoc. 2013;105:112–27.
  • Masoumi SJ, Mehrabani D, Saberifiroozi M, et al. The effect of yogurt fortified with Lactobacillus acidophilus and Bifidobacterium sp. probiotic in patients with lactose intolerance. Food Sci Nutr. 2021;9:1704–11.
  • Ibrahim SA, Gyawali R, Awaisheh SS, et al. Fermented foods and probiotics: An approach to lactose intolerance. J Dairy Res. 2021;88:357–65.
  • Morelli L, Amrani N, Goulet O, et al. Lactose intolerance: clinical symptoms, diagnosis and treatment. Global Diabetes Open Access Journal. 2019;1:1–10.
  • Kok CR, Hutkins R. Yogurt and other fermented foods as sources of health-promoting bacteria. Nutr Rev. 2018;76(Suppl 1):4–15.

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