Editing Lactose intolerance (section)

== Management ==
When lactose intolerance is due to secondary lactase deficiency, treatment of the underlying disease may allow lactase activity to return to normal levels.<ref name=Vandenplas2015>{{cite journal | vauthors = Vandenplas Y | title = Lactose intolerance | journal = Asia Pacific Journal of Clinical Nutrition | volume = 24  | issue =  Suppl 1| pages = S9–13 | year = 2015 | pmid = 26715083 | doi = 10.6133/apjcn.2015.24.s1.02 }}</ref> In people with celiac disease, lactose intolerance normally reverts or improves several months after starting a [[gluten-free diet]], but temporary dietary restriction of lactose may be needed.<ref name=BerniCananiPezzella2016 /><ref name=LevyBernstein2014>{{cite journal | vauthors = Levy J, Bernstein L, Silber N | title = Celiac disease: an immune dysregulation syndrome | journal = Current Problems in Pediatric and Adolescent Health Care | volume = 44 | issue = 11 | pages = 324–7 | date = December 2014 | pmid = 25499458 | doi = 10.1016/j.cppeds.2014.10.002 | type = Review | quote = Initially, reduced levels of lactase and sucrase activities might necessitate further dietary restrictions until the villi have healed and those sugars are better tolerated. }}</ref>

People with primary lactase deficiency cannot modify their body's ability to produce lactase.<ref name=NIH2014Dig /> In societies where lactose intolerance is the norm, it is not considered a condition that requires treatment. However, where dairy is a larger component of the normal diet, a number of efforts may be useful. There are four general principles in dealing with lactose intolerance: avoidance of dietary lactose, substitution to maintain nutrient intake, regulation of calcium intake, and use of enzyme substitute.<ref name="Berdanier" /> Regular consumption of dairy food by lactase deficient individuals may also reduce symptoms of intolerance by promoting colonic bacteria adaptation.<ref name="SilanikoveLeitner2015" />

=== Dietary avoidance ===
The primary way of managing the symptoms of lactose intolerance is to limit the intake of lactose to a level that can be tolerated.<ref name="NHS2016">{{cite web|url=http://www.nhs.uk/Conditions/lactose-intolerance/Pages/Treatment.aspx|title=Lactose intolerance - Treatment|website=NHS UK|access-date=11 August 2017|url-status=live|archive-url=https://web.archive.org/web/20170718135858/http://www.nhs.uk/Conditions/lactose-intolerance/Pages/Treatment.aspx|archive-date=18 July 2017}}</ref> Lactase deficient individuals vary in the amount of lactose they can tolerate,<ref name=NIH2014Dig/> and some report that their tolerance varies over time, depending on health status and pregnancy.<ref>{{Emedicine|med|3429|Lactose Intolerance}} Roy, Barakat, Nwakakwa, Shojamanesh, Khurana, July 5, 2006</ref><ref name="Szilagyi2015">{{cite journal | vauthors = Szilagyi A | title = Adaptation to Lactose in Lactase Non Persistent People: Effects on Intolerance and the Relationship between Dairy Food Consumption and {{sic|Evalu|tion|nolink=y}} of Diseases | journal = Nutrients | volume = 7 | issue = 8 | pages = 6751–79 | date = August 2015 | pmid = 26287234 | pmc = 4555148 | doi = 10.3390/nu7085309 | type = Review | doi-access = free }}</ref> However, as a rule of thumb, people with primary lactase deficiency and no small intestine injury are usually able to consume at least 12 grams of lactose per sitting without symptoms, or with only mild symptoms, with greater amounts tolerated if consumed with a meal or throughout the day.<ref name="NIH2014Dig" /><ref name="Szilagyi2015" /><ref name="SilanikoveLeitner2015">{{cite journal | vauthors = Silanikove N, Leitner G, Merin U | title = The Interrelationships between Lactose Intolerance and the Modern Dairy Industry: Global Perspectives in Evolutional and Historical Backgrounds | journal = Nutrients | volume = 7 | issue = 9 | pages = 7312–31 | date = August 2015 | pmid = 26404364 | pmc = 4586535 | doi = 10.3390/nu7095340 | type = Review | doi-access = free }}</ref>

{| class="wikitable floatright sortable" style="text-align:right"
|+'''Typical lactose levels in dairy products<ref name=gastroau>{{cite web|url=http://www.gastro.net.au/diets/lactose.html|title=Diet for Lactose Intolerance|url-status=live|archive-url=https://web.archive.org/web/20051224060911/http://www.gastro.net.au/diets/lactose.html|archive-date=2005-12-24}}</ref>'''
! Dairy product !! Serving<br /> size !! Lactose<br /> content !! Fraction
|-
|{{left}} Milk, regular
| 250 ml(g)
| 12 g
| 4.8%{{0}}
|-
|{{left}} Milk, reduced fat
| 250 ml(g)
| 13 g
| 5.2%{{0}}
|-
|{{left}} Yogurt, plain, regular
| 200 g
| 9 g
| 4.5%{{0}}
|-
|{{left}} Yogurt, plain, low-fat
| 200 g
| 12 g
| 6.0%{{0}}
|-
|{{left}} Cheddar cheese
| 30 g
| 0.02 g
| 0.07%
|-
|{{left}} Cottage cheese
| 30 g
| 0.1 g
| 0.33%
|-
|{{left}} Butter
| 5 g
| 0.03 g
| 0.6%{{0}}
|-
|{{left}} Ice cream
| 50 g
| 3 g
| 6.0%{{0}}
|}

Lactose is found primarily in [[dairy product]]s, which vary in the amount of lactose they contain:
* '''Milk''' – unprocessed cow's milk is about 4.7% lactose; [[goat milk|goat's milk]] 4.7%;<ref>{{cite web|url=http://www.goatworld.com/articles/goatmilk/colostrum.shtml|title=Composition of Human, Cow, and Goat Milks|work=GoatWorld.com|first=Harold|last=Eddleman|date=25 December 2003|url-status=live|archive-url=https://web.archive.org/web/20070928192428/http://www.goatworld.com/articles/goatmilk/colostrum.shtml|archive-date=28 September 2007}}</ref> [[Sheep milk|sheep's milk]] 4.7%;<ref>{{cite web|url= https://www.food-intolerance-network.com/food-intolerances/lactose-intolerance/tables-of-lactose-content.html|title= Amount of Lactose in Milk Products|date= 21 November 2013|website= food-intolerance-network.com|publisher= Food Intolerance Network|access-date= 7 September 2017|url-status= live|archive-url= https://web.archive.org/web/20170907213920/https://www.food-intolerance-network.com/food-intolerances/lactose-intolerance/tables-of-lactose-content.html|archive-date= 7 September 2017}}</ref> [[buffalo milk]] 4.86%;<ref name="Peeva">{{cite journal|author=Peeva|year=2001|title=Composition of buffalo milk. Sources of specific effects on the separate components|url=http://bjas.hit.bg/07/693A.htm|journal=Bulgarian Journal of Agricultural Science|volume=7|pages=329–35|url-status=dead|archive-url=https://web.archive.org/web/20070829232522/http://bjas.hit.bg/07/693A.htm|archive-date=2007-08-29}}</ref> and [[Domestic yak|yak milk]] 4.93%.<ref>{{cite journal|vauthors=Jiang XP, Liu GQ, Wang C, Mao YJ, Xiong YZ|title=Milk trait heritability and correlation with heterozygosity in yak|journal=Journal of Applied Genetics|volume=45|issue=2|date=2004|pmid=15131352|pages=215–24|url=http://jag.igr.poznan.pl/2004-Volume-45/2/pdf/2004_Volume_45_2-215-224.pdf|archive-url=https://web.archive.org/web/20080307083908/http://jag.igr.poznan.pl/2004-Volume-45/2/pdf/2004_Volume_45_2-215-224.pdf|archive-date=2008-03-07|url-status=live}}</ref>
* '''Sour cream''' and '''buttermilk''' – if made in the traditional way, this may be tolerable, but most modern brands add milk solids.<ref>{{cite journal|vauthors=Reger JV, Combs WB, Coulter ST, Koch RB |date=February 1, 1951|title=A Comparison of Dry Sweet Cream Buttermilk and Non-Fat Dry Milk Solids in Breadmaking|url=https://www.journalofdairyscience.org/article/S0022-0302(51)91682-7/abstract|journal=Journal of Dairy Science|volume=34|issue=2|pages=136–44|doi=10.3168/jds.S0022-0302(51)91682-7|doi-access=free}}</ref>
* '''Yogurt''' – [[Lactobacillus acidophilus|lactobacilli]] used in the production of [[yogurt]] metabolize lactose to varying degrees, depending on the type of yogurt.<ref>{{cite web |first=Sharon |last=Perkins |date=19 November 2018  |publisher=SFGATE |url=http://healthyeating.sfgate.com/can-lactose-intolerant-eat-yogurt-aged-cheese-6130.html|title=Can a Lactose Intolerant Eat Some Yogurt & Aged Cheese?|url-status=live|archive-url=https://web.archive.org/web/20150428164624/http://healthyeating.sfgate.com/can-lactose-intolerant-eat-yogurt-aged-cheese-6130.html|archive-date=2015-04-28}}</ref> Some bacteria found in yogurt also produce their own [[lactase]], which facilitates digestion in the intestines of lactose intolerant individuals.<ref name="SilanikoveLeitner2015" />
* '''Cheese''' – The [[curdling]] of cheese concentrates most of the lactose from milk into the [[whey]]: fresh [[cottage cheese]] contains 7% of the lactose found in an equivalent mass of milk.<ref name=gastroau/> Further fermentation and [[Cheese ripening|aging]] converts the remaining lactose into [[lactic acid]]; traditionally made [[hard cheese]]s, which have a long ripening period, contain virtually no lactose:<ref name=ilovecheese>{{cite web|url=http://www.ilovecheese.com/lactose_intolerant_faqs.asp|title=Dairy Good: Home|url-status=live|archive-url=https://web.archive.org/web/20130730190352/http://www.ilovecheese.com/lactose_intolerant_faqs.asp|archive-date=2013-07-30}}</ref> cheddar contains less than 1.5% of the lactose found in an equivalent mass of milk.<ref name=gastroau/> However, manufactured cheeses may be produced using processes that do not have the same lactose-reducing properties.<ref>{{cite journal |last1=Muthukummarappan |first1=K |last2=Biswas |first2=A.C. |last3=Metzger |first3=L.E. |last4=Kapoor |first4=R |title=Effect of Natural Cheese Characteristics on Process Cheese Properties |url=https://www.journalofdairyscience.org/article/S0022-0302(07)71648-X/fulltext |journal=Journal of Dairy Science |year=2007 |volume=90 |issue=4 |pages=1625–1634 |publisher=Plum X Metrics |doi=10.3168/jds.2006-746 |pmid=17369202 |s2cid=32630538 |access-date=April 19, 2022|doi-access=free }}</ref>

There used to be<ref name=Portnoy>{{cite journal |last1=Portnoy |first1=Matilde |last2=Barbano |first2=David M. |title=Lactose: Use, measurement, and expression of results |journal=Journal of Dairy Science |date=July 2021 |volume=104 |issue=7 |pages=8314–8325 |doi=10.3168/jds.2020-18706|pmid=33814136 |doi-access=free }}</ref> a lack of standardization on how lactose is measured and reported in food. The different molecular weights of anhydrous lactose or lactose monohydrate result in up to 5% difference.<ref>{{cite web|url=http://drinc.ucdavis.edu/goat1.htm|title=Goat Dairy Foods|url-status=dead|archive-url=https://web.archive.org/web/20071111141237/http://drinc.ucdavis.edu/goat1.htm|archive-date=2007-11-11|access-date=2007-10-11}}</ref> One source recommends using the "carbohydrates" or "sugars" part of the nutritional label as surrogate for lactose content,<ref name=ilovecheese/> but such "lactose by difference" values are not assured to correspond to real lactose content.<ref name=Portnoy/> The stated dairy content of a product also varies according to manufacturing processes and labelling practices, and commercial terminology varies between languages and regions.<ref name="Berdanier" /> As a result, absolute figures for the amount of lactose consumed (by weight) may not be very reliable.

[[Kosher]] products labeled ''[[pareve]]'' or ''[[fleishig]]'' are free of milk. However, if a "D" (for "dairy") is present next to the circled "K", "U", or other ''[[hechsher]]'', the food product likely contains milk solids,<ref name="OHSU">{{cite web|url=http://www.ohsu.edu/xd/health/health-information/topic-by-id.cfm?ContentTypeId=90&ContentId=P01696|title=General guidelines for milk allergy|publisher=Oregon Health & Science University|url-status=dead|archive-url=https://archive.today/20121212035247/http://www.ohsu.edu/xd/health/health-information/topic-by-id.cfm?ContentTypeId=90&ContentId=P01696|archive-date=2012-12-12}}</ref> although it may also simply indicate the product was produced on equipment shared with other products containing milk derivatives.

Lactose is also a commercial [[food additive]] used for its texture, flavor, and adhesive qualities. It is found in additives labelled as [[casein]], [[Caseinase|caseinate]], [[whey]], [[lactoserum]], [[milk solids]], [[modified milk ingredients]], etc.{{Citation needed|date=August 2017}} As such, lactose is found in foods such as processed meats ([[sausage]]s/[[hot dog]]s, sliced meats, [[pâté]]s),<ref name="OHSU" /> gravy stock powder, [[margarine]]s,<ref>{{cite web |title=Margarine Regulations |url=http://www.gov.ns.ca/JUST/REGULATIONS/regs/marge.htm |url-status=live |archive-url=https://web.archive.org/web/20071011202241/http://gov.ns.ca/JUST/REGULATIONS/regs/marge.htm |archive-date=2007-10-11 }}</ref> sliced [[bread]]s,<ref>{{cite web |title=Enriched White Bread in Canada |url=http://www.celiac.ca/Articles/PAB%20Enriching%20GF%20Foods.html |publisher=The Canadian Celiac Association |url-status=dead |archive-url=https://web.archive.org/web/20071203005124/http://www.celiac.ca/Articles/PAB%20Enriching%20GF%20Foods.html |archive-date=2007-12-03 |access-date=2007-10-11 }}</ref><ref>{{cite journal |title=Influence of Nonfat Dry Milk Solids on the Nutritive Value of Bread |journal=Journal of Dairy Science |date=December 1946 |volume=29 |issue=12 |pages=821–9 | last1 = Riggs | first1 = Lloyd K | last2 = Beaty | first2 = Annabel | last3 = Johnson | first3 = Arnold H |doi=10.3168/jds.S0022-0302(46)92546-5 |doi-access=free}}</ref> breakfast cereals, [[potato chip]]s,<ref name="Bartek">{{cite web |title=Bartek, food additive company |url=http://www.bartek.ca/pdfs/Applications/SavouryProducts/SavourySnackFoods/Savoury%20Snack%20Foods%20Alphabetical%20List%20of%20Product%20Names.pdf |url-status=dead |archive-url=https://web.archive.org/web/20081217083729/http://www.bartek.ca/pdfs/Applications/SavouryProducts/SavourySnackFoods/Savoury%20Snack%20Foods%20Alphabetical%20List%20of%20Product%20Names.pdf |archive-date=2008-12-17 |access-date=2007-10-11 }}</ref> [[Food processing|processed foods]], [[medication]]s, prepared meals, meal replacements (powders and bars), protein supplements (powders and bars), and even [[beer]]s in the [[milk stout]] style. Some barbecue sauces and liquid cheeses used in fast-food restaurants may also contain lactose. When dining out, carrying lactose intolerance cards that explain dietary restrictions in the local language can help communicate needs to restaurant staff.<ref name="AllergyFacts2">{{cite web |title=Allergen Card - Milk/Dairy |url=https://allergyfacts.org.au/shop/food-preparation-tools/allergen-cards/allergen-card-milk-dairy |access-date=16 July 2024 |website=Allergy & Anaphylaxis Australia}}</ref> Lactose is often used as the primary filler (main ingredient) in most prescription and non-prescription solid pill form medications, though product labeling seldom mentions the presence of 'lactose' or 'milk', and neither do product monograms provided to pharmacists, and most pharmacists are unaware of the very wide scale yet common use of lactose in such medications until they contact the supplier or manufacturer for verification.{{Citation needed|date=April 2015}}

=== Milk substitutes ===
{{further|Milk#Reduction or elimination of lactose|Milk substitute}}

[[Plant milk|Plant-based milks]] and derivatives such as [[soy milk]], [[rice milk]], [[almond milk]], [[coconut milk]], [[hazelnut]] milk, [[oat milk]], [[hemp milk]], macadamia nut milk, and [[peanut milk]] are inherently lactose-free.  Low-lactose and lactose-free versions of foods are often available to replace dairy-based foods for those with lactose intolerance.<ref>{{cite book |doi=10.1002/9781118906460.ch2f |chapter=Dairy Products and Their Role in Human Health |chapter-url={{Google books|z100DwAAQBAJ|page=248|plainurl=yes}} |title=Advances in Dairy Products |pages=248–61 |year=2017 |last1=Trotta |first1=Teresa |last2=Posa |first2=Francesca |last3=Mori |first3=Giorgio |last4=Porro |first4=Chiara |isbn=978-1-118-90646-0 }}</ref>

=== Lactase supplements ===
When lactose avoidance is not possible, or on occasions when a person chooses to consume such items, then enzymatic lactase supplements may be used.<ref name="Montalto">{{cite journal | vauthors = Montalto M, Curigliano V, Santoro L, Vastola M, Cammarota G, Manna R, Gasbarrini A, Gasbarrini G | title = Management and treatment of lactose malabsorption | journal = World Journal of Gastroenterology | volume = 12 | issue = 2 | pages = 187–91 | date = January 2006 | pmid = 16482616 | pmc = 4066025 | doi=10.3748/wjg.v12.i2.187 | doi-access = free }}</ref><ref>{{cite journal | vauthors = He M, Yang Y, Bian L, Cui H | title = [Effect of exogenous lactase on the absorption of lactose and its intolerance symptoms] | language = zh | journal = Wei Sheng Yan Jiu = Journal of Hygiene Research | volume = 28 | issue = 5 | pages = 309–11 | date = September 1999 | pmid = 12712706 }}</ref>

Lactase enzymes similar to those produced in the small intestines of humans are produced industrially by [[fungi]] of the [[genus]] ''[[Aspergillus]]''. The enzyme, [[Beta-galactosidase|β-galactosidase]], is available in tablet form in a variety of doses, in many countries without a prescription. It functions well only in high-acid environments, such as that found in the human gut due to the addition of gastric juices from the stomach. Unfortunately, too much acid can denature it,<ref>{{cite journal | vauthors = O'Connell S, Walsh G | s2cid = 22205720 | title = Physicochemical characteristics of commercial lactases relevant to their application in the alleviation of lactose intolerance | journal = Applied Biochemistry and Biotechnology | volume = 134 | issue = 2 | pages = 179–91 | date = August 2006 | pmid = 16943638 | doi = 10.1385/ABAB:134:2:179 }}</ref> so it should not be taken on an empty stomach. Also, the enzyme is ineffective if it does not reach the small intestine by the time the problematic food does. Lactose-sensitive individuals can experiment with both timing and dosage to fit their particular needs.

While essentially the same process as normal intestinal lactose digestion, direct treatment of milk employs a different variety of industrially produced lactase. This enzyme, produced by [[yeast]] from the genus ''[[Kluyveromyces]]'', takes much longer to act, must be thoroughly mixed throughout the product, and is destroyed by even mildly acidic environments. Its main use is in producing the lactose-free or lactose-reduced dairy products sold in supermarkets.<ref>{{Citation|last1=Belloch|first1=C.|title=Yeasts and Molds {{!}} Kluyveromyces spp.|date=2011-01-01|url=https://www.sciencedirect.com/science/article/pii/B9780123744074004994|encyclopedia=Encyclopedia of Dairy Sciences |edition=2nd |pages=754–764|editor-last=Fuquay|editor-first=John W.|place=San Diego|publisher=Academic Press|isbn=978-0-12-374407-4|access-date=2022-01-14|last2=Querol|first2=A.|last3=Barrio|first3=E.}}</ref>

=== Rehabituation to dairy products ===
Regular consumption of dairy foods containing lactose can promote a colonic bacteria adaptation, enhancing a favorable microbiome, which allows people with primary lactase deficiency to diminish their intolerance and to consume more dairy foods.<ref name="SilanikoveLeitner2015" /><ref name="Szilagyi2015" /><ref>{{cite magazine|url=http://www.agriculture.purdue.edu/agricultures/past/Spring1998/1998-Spring-Spotlights.pdf|title=Lactose intolerant? Drink more milk |first=Steve|last=Tally |magazine=Agricultures Magazine |page=2 |volume=1 |number=2 |date=1998 |archive-url=https://web.archive.org/web/20060904071717/http://www.agriculture.purdue.edu/agricultures/past/Spring1998/1998-Spring-Spotlights.pdf |archive-date=2006-09-04 |url-status=live}} Steve Tally</ref> The way to induce tolerance is based on progressive exposure, consuming smaller amounts frequently, distributed throughout the day.<ref name=GrenovBriend2016>{{cite journal | vauthors = Grenov B, Briend A, Sangild PT, Thymann T, Rytter MH, Hother AL, Mølgaard C, Michaelsen KF | s2cid = 39762161 | title = Undernourished Children and Milk Lactose | journal = Food and Nutrition Bulletin | volume = 37 | issue = 1 | pages = 85–99 | date = March 2016 | pmid = 26893059 | doi = 10.1177/0379572116629024 | doi-access = free }}</ref> Lactose intolerance can also be managed by ingesting live yogurt cultures containing [[Lactobacillus acidophilus|lactobacilli]] that are able to digest the lactose in other dairy products.<ref>{{cite journal |doi=10.2903/j.efsa.2010.1763 |title=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 |journal=EFSA Journal |volume=8 |issue=10 |year=2010 |doi-access=free }}</ref>