It’s not possible to self-diagnose lactose intolerance. This also includes the tests you could find on the Internet, as these tests are not scientifically validated.

Usually, self-diagnosis is based on dairy avoidance and on the presumed consequent cessation of symptoms. Yet, lactose intolerance cannot be diagnosed outside strict medical control. The proper way to diagnose lactose intolerance is to measure, in the exhaled air, the hydrogen produced by the intestinal flora after consumption of a standard dose of lactose (usually 20 to 50 g) and when one or many of the following symptoms occur: bloating, diarrhea, and flatulence. This diagnosis if performed under medical control.

When a medical diagnosis is performed, only 50% of self-diagnosis of lactose intolerance is confirmed.

Sources:

• Hermans et al. Am J Gastroenterol 1997;92:981-4.
• Nicklas et al. Nutrition Today 2009;44:222-7.
• Suarez et al. N Engl J Med 1995;333:1-4.

Fermented foods have been produced and consumed since the development of human civilization. In this paper, M L Marco (University of California, Davis) and colleagues reviewed the evidence that fermented foods provide health benefits well-beyond the starting food materials.

The unknown properties of fermented foods

Fermented foods, such as yogurt and fermented milk, wine and beer, sauerkraut and kimchi, are made through controlled microbial growth and enzymatic conversion of major and minor food components. Since several years, there is a growing interest in their health-promoting potential. Some experts have even suggested that fermented food should be included as part of national dietary recommendations. Marco noted that recent human clinical studies on fermented foods support the possibility that the fermentation, and the contribution of microbes, in particular, may provide additional properties beyond basic nutrition. Recent relevant data suggest benefits of some fermented foods in weight management and numerous other chronic diseases.

A potential necessity for fermented foods

There still critical needs for additional fundamental research and randomized, controlled, clinical trials to evaluate the effects of different fermented foods. However, wrote the authors, the benefits of fermented food are likely greater than the sum of their individual microbial, nutritive, or bioactive components. The research could highlight the relevance, and potentially the necessity, of certain fermented foods in the human diet and justification for inclusion into national dietary guidelines.

4 reasons to eat more fermented foods like yogurt

• Fermentation can enhance or alter nutritive and health-modulating properties of food constituents.
• Microbes in fermented foods helps to digest some foods, produce vitamins like B12 and K, introduce new compounds to the foods that are delivered to the gut.
• Many of the species found in fermented foods are phylogenetically related to probiotic strains.
• Fermented foods can be an important dietary source of live microorganisms.

To learn more, read the original article.

Source: Marco M L et al. Current Opinion in Biotechnology 2017;44:94-102.

The regular consumption of dairy food in individuals with difficulties to digest lactose could lead to an adaptation of their gut microbiota (the microorganism population that lives in the digestive tract) and to an improvement of symptoms, which allow them to consume more dairy foods.

The consumption of live bacteria can increase the presence of certain bacteria strain without, however, changing the overall gut microbiota constitution. Yogurt contains live bacteria, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, which break down some of the lactose it contains, making it easier for individuals who have difficulty digesting lactose.

Moreover, if it is not digested in the small intestine, lactose may be used by the intestinal microbiota as a nutrient (prebiotic). Lactose and other milk sugars also promote the growth of bifidobacteria in the gut and may play a life-long role in countering the aging-associated decline of some immune functions.

Sources:

• Amaretti et al. Appl Microbiol Biotechnol 2006;73:654-62.
• 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.
• He et al. Eur J Clin Invest 2008;38:541-7.
• Vandenplas et al. Asia Pac J Clin Nutr 2015;24 Suppl 1:S9-13.
• Vulevic et al. Br J Nutr 2015;114:586-95.

Lactose intolerance manifests itself by one or many of the following symptoms: bloating, diarrhea, and flatulence, which occur after lactose consumption.

Lactose, the sugar naturally found in milk and dairy, is usually transformed in the intestine by lactase, an enzyme, into glucose and galactose, both simpler sugars used by our body for energy and various functions. The activity of lactase is high during infancy and slowly decline after weaning. In some individuals, for whom the activity of lactase is reduced, undigested lactose consequently enters the colon where it is fermented by the resident microbiota (the microorganism population that lives in the digestive tract). Bacterial fermentation leads to the formation of gas (hydrogen, carbon dioxide, methane), lactic and acetic acids, which increases gut transit time and intracolonic pressure, resulting possibly in bloating, diarrhea, and flatulence.
The amount of lactose that triggers these symptoms differs among individuals. Most of individuals with difficulty to digest lactose (lactose maldigestion) can consume lactose in dairy foods in modest amount, up to 12 g of lactose in one intake or up to 24 g in small amounts across the day during or at the end of a meal, without experiencing the symptoms mentioned above.

For that matter, the European Food Safety Authority has issued a scientific opinion that claims that the consumption of live yogurt cultures in yogurt, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, improves digestion of lactose in yogurt in individuals with lactose maldigestion.

Sources:

• 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.
• Misselwitz et al. United European Gastroenterol J 2013;1:151-9.
• Suarez et al. N Engl J Med 1995;333:1-4.

Dairy are sometimes blamed, because they would increase the risk of certain chronic disease, generating skepticism among consumers, who turn to plant-based alternatives. In this review, T. Kongerslev Thorning (University of Copenhagen) and colleagues examined the totality of scientific evidence between milk, dairy products and human health. Their conclusions support their place in a balanced diet.

Less weight gain over time

Cardiovascular diseases, cancer and type 2 diabetes (T2D) are among the main causes of the loss of disease-free years in numerous countries. The rise in obesity also increases the risk of these chronic diseases. So it is crucial to better understand how foods like milk and dairy products can influence a particularly alarming context. This narrative review is mainly based on meta-analyses of observational studies and randomized controlled trials. The main results indicate that, in children, milk and dairy products are associated with a lower risk of obesity. Results are also favorable for obesity in adults, with an improvement of body composition and a better weight loss during a diet including dairy products.

More benefits than risks

The study also shows that the risk of T2D and cardiovascular disease, particularly stroke, is reduced with regular milk and dairy products consumption. Despite there was no significant association with the risk of bone fractures, results highlighted beneficial effects of milk and dairy intake on bone mineral density. This food category is also associated with a reduced risk of some cancer subtypes (colorectal, bladder, gastric and breast cancer) and has no detrimental effects on prostate cancer incidence. The authors concluded that milk and dairy products show more beneficial than detrimental effects on health. More studies are needed before any evidence-based conclusion on their health value can be drowned. Here are some good reasons to get your dairy!

To learn more, read the original article.

Source: Kongerslev Thorning T el al. Food & Nutrition Research 2016;60:32527.

No. Allergy is a hypersensitivity of the immune system to some elements in the environment that causes no to little problem to most people. Common food allergies are to peanuts, cow’s milk, eggs, tree nuts, fish, shellfish, soy and wheat. In cow’s milk allergy, the immune system overreacts to one or more proteins contained in cow’s milk such as caseins and whey proteins. Symptoms include hives, swelling, nausea and wheezing and can arise within an hour and even up to 72 hours after drinking cow’s milk.

Lactose intolerance is related to lactose, which is not a protein but a type of sugar naturally found in milk and dairy. It’s the inability to digest lactose that results in bloating, diarrhea, and gas. Lactose is not a milk protein but a sugar and it is not targeted by the immune system.

People suffering from cow’s milk allergies should avoid milk and dairy foods whereas people with lactose intolerance should not avoid milk and dairy foods but rather consume dairy in modest amounts, up to 12g in one intake or up to 24 g, preferably in small amounts across the day, during or at the end of a meal (not at beginning), without symptoms. Lactose intolerants are also recommended to consume different forms of dairy such as yogurt, which facilitates lactose digestion, and some cheeses like aged-cheeses, which contain very low to no lactose.

Sources:

• Crittenden et al. J Am Coll Nutr 2005;24:582S-91S.
• 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.
• Luyt et al. Clin Exp Allergy 2014;44:642-72.
• Misselwitz et al. United European Gastroenterol J 2013;1:151-9.
• Suarez et al. N Engl J Med 1995;333:1-4.

Yogurt can be consumed by everyone.

More specifically, yogurt is recommended for lactose maldigesters and lactose intolerants because the lactose in yogurt is digested by the lactase produced by live bacteria Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus.

Yogurt is a good source of several micronutrients such as calcium, magnesium and high- quality proteins, which help to control appetite and glycemia. Yogurt consumption helps to improve the overall diet quality and promotes the replacement of less healthy foods. Yogurt consumption is associated with a lower risk for type 2 diabetes.

Sources:

• 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.
• Keast et al. Nutrients 2015;7:1577-93.
• Lecerf  et al. The FASEB Journal 2014;28.
• Martinchik et al. Voprosy pitaniia 2016;85:56-65.
• Mistura et al. International journal of food sciences and nutrition 2016;67:232-8.
• O’Connor et al. Diabetologia 2014;57:909-17.
• Panahi et al. J Am Coll Nutr 2016:1-15.
• Savaiano et al. Am J Clin Nutr 2014;99:1251S-5S.
• Wang et al. Nutrition research 2013;33:18-26.
• Wang et al. Int J Obes (Lond) 2014;38:299-305
• Webb et al. Nutrition reviews 2014;72:180-9.

Intake of free sugar should be less than 10 % of total daily energy intake, according to WHO. But where are we today? This study, conducted by V. Azaïs-Braesco et al. reviewed the data on sugar intakes from European countries, and identified the main contributors to added sugar intakes. Yogurt is definitely not one of them!

The first source of sugar: sweet products of course!

Added sugars (or non-milk extrinsic sugars) are all mono- and disaccharides added to foods by the manufacturer, cook or consumer, and also sugar naturally present in honey and syrup*. Free sugars also include sugars naturally present in fruit juice. This review covers 11 European surveys driven in 10 countries, among which 7 provided accurate estimates on total added sugar intakes. Results shows that mean intake of added sugar in adults represents from 7 to 11 % of total energy intake, a percentage mainly represented by sweet products. Who are the biggest consumers? Apparently Men! They had a bigger intake in sugars (in g/d) than woman. But this difference disappeared when it’s expressed to total energy intake. In other words, women have at least a bigger bit of a sweet tooth than men…

Yogurt: far behind others

Unsurprisingly, the major contributor in adults was sweet products: confectionery, chocolates, cakes and biscuits, sugar, and jam, represent 36  to 61 % of total added sugar intakes. The second contributor were beverages (12 to 31% in adults, fruit juices excepted). Dairy appears as the third source of added sugar, with only 4 to 15 % of the total added sugar intake in adults. With providing no more than 8 % of the total added sugar, depending on the country, yogurt appears as a relatively low contributor to sugar intake in Europe.

In conclusion: if you like sweet yogurts, you can consume branded yogurt without feeling guilty. If you sweeten a plain yogurt yourself, consider adding moderate and varying the sweetening ingredients (white or brown sugar, honey, maple syrup, jam, compote …). The most important thing is to consume daily dairy products!

To learn more, read the original article.

Source: Azaïs-Braesco V et al. Nutrition Journal 2017;16:6.

* Basically, non milk extrinsic sugars include table sugar, honey, glucose, fructose and glucose syrups, sugars added to food and sugars in fruit juices.

Lactose intolerance can impair quality of life but has, likewise, no direct consequence on health. Likewise lactose maldigestion has also no consequence on health. Yet, perceived or diagnosed lactose intolerance is one of the reasons for limiting or avoiding dairy food. Thus, the only health consequence of lactose intolerance comes from the possible nutrient shortcomings consequent to dairy avoidance, such as low calcium intake. As stated by the European Food Safety Authority, low calcium intake may impair the maintenance of normal bones and teeth.

In order to reach the required calcium intakes, lactose maldigesters are recommended to consume other forms of dairy products such as cheeses that contains low or no lactose (cheddar, provolone, mozzarella, Grana padano, etc.) and yogurts that contain live bacteria, which improve the digestion of the lactose contained in yogurt. Indeed, yogurt consumers have overall a better calcium intake, a more balanced diet than non-yogurt consumers. Thus, yogurt is a marker of a good quality diet.

Sources:

• Bailey et al. J Natl Med Assoc 2013;105:112-27.
• Black et al. Am J Clin Nutr 2002;76:675-80.
• Casellas et al. European journal of clinical nutrition 2016;70:1068-72.
• Efsa Panel on Dietetic Products N, Allergies. Scientific Opinion on the substantiation of health claims related to calcium and maintenance of normal bone and teeth (ID 2731, 3155, 4311, 4312, 4703), maintenance of normal hair and nails (ID 399, 3155), maintenance of normal blood LDL-cholesterol concentrations (ID 349, 1893), maintenance of normal blood HDL-cholesterol concentrations (ID 349, 1893), reduction in the severity of symptoms related to the premenstrual syndrome (ID 348, 1892), “cell membrane permeability” (ID 363), reduction of tiredness and fatigue (ID 232), contribution to normal psychological functions (ID  233), contribution to the maintenance or achievement of a normal body weight (ID 228, 229) and regulation of normal cell division and differentiation (ID 237) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010;8:n/a-n/a.
• Heaney et al. J Am Coll Nutr 2000;19:83S-99S. Heaney et al. J Am Coll Nutr 2009;28 Suppl 1:82S-90S.
• Keast et al. Nutrients 2015;7:1577-93.
• Lecerf et al. The FASEB Journal 2014;28.
• Lukito et al. Asia Pac J Clin Nutr 2015;24 Suppl 1:S1-8.
• Martinchik et al. Voprosy pitaniia 2016;85:56-65.
• Mistura et al. International journal of food sciences and nutrition 2016;67:232-8.
• Nicklas et al. Am J Clin Nutr 2011;94:191-8.
• Suchy et al. NIH Consens State Sci Statements 2010;27:1-27.
• Wang et al. Nutrition research 2013;33:18-26.
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Lactose intolerance concerns very few people while lactose maldigestion concerns 70-75% of the world population. There is a difference between these two situations.

Lactose maldigestion is due to the normal incapacity of our intestine to transform lactose into glucose and galactose, both simpler sugars used by our body for energy and various functions. Lactose intolerance however is lactose maldigestion that results in one or many symptoms of intestinal discomfort such as bloating, diarrhea, and gas.

Lactose maldigestion appears after weaning, when the activity of lactase begins to naturally decline. Lactose maldigestion varies between different populations and on whether dairy products are consumed during adulthood. Lactase activity decline is more common in people of Asian, African, South American, Southern European, and Australian Aboriginal heritage than in people of Northern European (Scandinavia, the British Islands and Germany) descent. Total lactase deficiency is rare (less than 50 patients in the world, mainly in Finland). It is a genetic disorder called congenital lactase deficiency. The severity of symptoms depends on the degree of lactase deficiency and they usually include nausea, abdominal cramps and bloating, vomiting, flatulence, diarrhea, dehydration, loose stool, metabolic acidosis, the presence of lactose in urine and a distended abdomen. Lactose-free diet is only needed for the rare patients with congenital lactase deficiency.

For lactose intolerants and maldigesters, avoidance of milk and dairy products could have health consequences. Small amounts of lactose can still be consumed without triggering any symptoms. The consumption of yogurt, which contains live bacteria that help digesting the lactose it contains, and of cheeses that contain low or no lactose is possible and even encouraged (cheddar, provolone, mozzarella, Grana padano, etc.).

Sources:

• Adolfsson et al. Am J Clin Nutr 2004;80:245-56.
• Black et al. Am J Clin Nutr 2002;76:675-80.
• Efsa Panel on Dietetic Products N, Allergies. Scientific Opinion on the substantiation of health claims related to calcium and maintenance of normal bone and teeth (ID 2731, 3155, 4311, 4312, 4703), maintenance of normal hair and nails (ID 399, 3155), maintenance of normal blood LDL-cholesterol concentrations (ID 349, 1893), maintenance of normal blood HDL-cholesterol concentrations (ID 349, 1893), reduction in the severity of symptoms related to the premenstrual syndrome (ID 348, 1892), “cell membrane permeability” (ID 363), reduction of tiredness and fatigue (ID 232), contribution to normal psychological functions (ID 233), contribution to the maintenance or achievement of a normal body weight (ID 228, 229) and regulation of normal cell division and differentiation (ID 237) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010;8:n/a-n/a.
• Heaney et al. J Am Coll Nutr 2000;19:83S-99S. Heaney RP. Dairy and bone health. J Am Coll Nutr 2009;28 Suppl 1:82S-90S.
• Lukito et al. Asia Pac J Clin Nutr 2015;24 Suppl 1:S1-8.
• Lukito et al. Asia Pac J Clin Nutr 2015;24 Suppl 1:S1-8.
• Misselwitz et al. United European Gastroenterol J 2013;1:151-9.
• Nicklas et al. Am J Clin Nutr 2011;94:191-8.
• Szilagyi et al. Asia Pac J Clin Nutr 2015;24 Suppl 1:S9-13.