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Gluten je beljakovina, ki jo najdemo v številnih žitih, vključno s pšenico, ječmenom in ržjo. Pogosto ga najdemo v živilih, kot so kruh, testenine, pica in žita. Ljudje s hudo avtoimunsko boleznijo celiakijo se na gluten odzovejo zelo močno.
Velika večina ljudi misli, da reagirajo na gluten čeprav temu ni tako
Celiakija prizadene le 1 % prebivalstva, nadaljnjih 6 % pa je lahko občutljivih na gluten brez celiakije (NCGS), kljub temu pa kar 22 % Kanadčanov poskuša iz svoje prehrane izločiti gluten[1]. Glede na raziskavo, ki jo je leta 2014 objavil nacionalni raziskovalni center Consumer Reports, kar 63 % Američanov meni, da bi lahko brezglutenska prehrana izboljšala njihovo duševno ali telesno zdravje. Kar tretjina Američanov pa ga zmanjšuje v upanju, da bo to izboljšalo njihovo zdravje ali preprečilo bolezni. [2]
Veliko večje je število ljudi, ki iz prehrane izločajo gluten v upanju, da bodo ublažili ali preprečili vrsto simptomov in bolezni - napihnjenost, debelost, možgansko meglo, Alzheimerjevo bolezen in avtizem. Trdnih diagnostičnih meril še ni, prav tako ne testov za ugotavljanje občutljivosti na gluten, zato je ugotavljanje, ali ima nekdo to bolezen, zelo subjektivno: večinoma gre za to, da se nekdo začne prehranjevati brez glutena in preveri, kako se počuti po tem.
Gluten ni krivec za gastrointestinalne simptome
Študija je pokazala, da se večina bolnikov s sumom na NCGS ob izzivanju z glutenom v dvojno slepem, s placebom nadzorovanem prehranskem izzivu ne prepozna, kar kaže na to, da gluten ni vzrok njihovih simptomov.[3] Bilo je povsem naključno, kako so se preiskovanci odzvali na gluten. Dejansko so se bolj odzvali na placebo kot na gluten.
Znanstveno dokazana potencialna zdravstvena tveganja, povezana s prehrano z nizko vsebnostjo glutena
Manj glutena v prehrani je dejansko pomenilo nekoliko večje tveganje za razvoj sladkorne bolezni tipa II V treh obsežnih prospektivnih kohortnih študijah ameriških moških in žensk je bil večji vnos glutena povezan z manjšim tveganjem za sladkorno bolezen tipa 2 v 20-28 letih spremljanja[4].
Motnje normalnega delovanja probiotikov Med zdravimi udeleženci je brezglutenska dieta bistveno zmanjšala številčnost koristnih bakterij (vrste Bifidobacterium, B. longum in Lactobacillus) v debelem črevesu, povečala število potencialno patogenih bakterij (vrste Escherichia coli in Enterobacteriaceae) v črevesju ter zavrla imunski odziv mononuklearnih celic periferne krvi na bakterije [5].
Pomanjkanje pomembnih hranil Brezglutenska prehrana običajno vsebuje malo vlaknin in mikrohranil, vključno z vitamini skupine B, železom in kalcijem, s katerimi so sicer bogati pšenični izdelki. [6]
Zakaj so brezglutenske diete tako priljubljene?
Robert H. Shmerling, dr. med., višji urednik pri Harvard Health Publishing, meni, da je priljubljenost povezana s kombinacijo različnih dejavnikov [7], med katerimi so:
Intuicija - zdi se, da je to dobra ideja.
Logika - Če je gluten slab za ljudi s celiakijo, je morda slab tudi zame.
Podpora znanih osebnosti - Če odpravo glutena spodbuja nekdo, ki ga občudujem, bi morda moral poskusiti tudi jaz.
Anekdota - Pričevanja so lahko močna. Ko slišim o nekom, ki je imel nadležne simptome, ki so po izločitvi glutena končno izginili, je to težko prezreti.
Trženje - Nikoli ne podcenjujte moči prepričevanja. Tisti, ki prodajajo brezglutenske izdelke ali knjige o brezglutenski dieti, so lahko prepričljivi, tudi če je znanstvenih dokazov za to malo.
Bodite pozorni na FODMAP
Včasih ljudi ne moti gluten, temveč drugi sladkorji, ki jih najdemo v pšenici. Alternativna hipoteza predvideva, da se ljudje, ki trdijo, da se njihovi simptomi ob brezglutenski dieti izboljšajo, morda dejansko odzivajo na drugo skupino ogljikovih hidratov v pšenici, imenovano FODMAP (fermentirani oligosaharidi, disaharidi, monosaharidi in polioli). Vendar so raziskave o tem še v zelo zgodnji fazi. Številne študije, v katere so bile vključene osebe z občutljivostjo na gluten ali dieto s FODMAPs, so majhne, zato so potrebne nadaljnje raziskave.
Preden poskusite brezglutensko dieto
Ni dokazov, da bi brezglutenska dieta koristila vsem, razen bolnikom s celiakijo in tistim, ki ne prenašajo glutena. Brezglutenska prehrana ni bolj zdrava in ne vsebuje več ali boljših hranilnih snovi. Številni brezglutenski izdelki vsebujejo dodatne aditive, da so okusni. Zaradi potencialne škode - in neznane koristi - rekreativnega izogibanja glutenu raziskovalci, ki se ukvarjajo s tem področjem, ljudem svetujejo, naj dvakrat premislijo, preden se odločijo za brezglutensko prehrano (razen seveda, če imajo celiakijo ali diagnosticirano alergijo). [8]
[1] https://badgut.org/information-centre/health-nutrition/maybe-it-isnt-glutens-fault/
[2] https://www.consumerreports.org/media-room/press-releases/2014/11/consumer-reports-debunks-common-myths-about-gluten/
[3] The effect of a controlled gluten challenge in a group of patients with suspected non-coeliac gluten sensitivity: A randomized, double-blind placebo-controlled challenge
H. F. Dale,J. G. Hatlebakk,N. Hovdenak,S. O. Ystad,G. A. Lied
https://doi.org/10.1111/nmo.13332
[4] Zong G, Lebwohl B, Hu FB, et al. Gluten intake and risk of type 2 diabetes in three large prospective cohort studies of US men and women. Diabetologia. 2018;61(10):2164-2173. doi:10.1007/s00125-018-4697-9
[5] Sanz Y (2010) Effects of a gluten-free diet on gut microbiota and immune function in healthy adult humans. Gut Microbes 1: 135–137
[6] Thompson T (2000) Folate, iron, and dietary fiber contents of the gluten-free diet. Journal of the American Dietetic Association 100: 1389–1396 [7] https://www.health.harvard.edu/staying-healthy/mediterranean-style-the-healthy-fats-and-healthy-carbs-diet
[8] https://www.vox.com/2015/4/30/8517749/gluten-free-diet-nutrition-celiac-disease
Stop blaming gluten health problems for it could be good for you
Gluten is a protein found in many grains, including wheat, barley and rye. It's common in foods such as bread, pasta, pizza and cereal. People with the serious autoimmune disorder celiac disease have an extreme reaction to gluten.
The vast majority of people who think they react to gluten don’t
Celiac disease affects just 1% of the population, and an estimated further 6% could have non-celiac gluten sensitivity (NCGS), yet as many as 22% of Canadians are trying to cut gluten out of their diets[1]. According to a survey by the Consumer Reports National Research Center published in 2014 a full 63% of Americans believe that a gluten-free diet could improve their mental or physical health. And up to a third of Americans are cutting back on it in the hope that it will improve their health or prevent disease. [2]
There is a much larger number of people who are cutting gluten from their diets in the hope of alleviating or avoiding a range of symptoms and diseases — bloating, obesity, brain fog, Alzheimer's, and autism. There are no firm diagnostic criteria yet, nor are there gluten-sensitivity tests, so determining whether someone has this condition is very subjective: it mostly involves putting someone on a gluten-free diet and seeing how they report feeling afterward.
Gluten is not the reason to blame for gastrointestinal symptoms
Study showed that the majority of patients with suspected NCGS are not able to identify when challenged with gluten in a double-blind placebo-controlled food challenge, indicating that gluten is not the cause of their symptoms.[3] It was completely random how the subjects responded to the gluten. They actually responded more to placebo than the gluten.
Scientific proven potential health risks associated with Low Gluten Diet
Less gluten in diets actually had a slightly higher risk of developing type II diabetes In three large prospective cohort studies of US men and women, higher gluten intake was associated with a lower risk of type 2 diabetes during 20–28 years of follow-up.[4]
Disturb the normal probiotics Among healthy participants, a gluten-free diet substantially decreased the abundance of beneficial bacteria (Bifidobacterium species, B. longum and Lactobacillus species) in the colon, increased potentially pathogenic bacteria (Escherichia coli and Enterobacteriaceae species) in the intestine, and suppressed the immune response of peripheral blood mononuclear cells to bacteria [5].
Lack of important nutrients A gluten-free diet is typically low in fibre and micronutrients including B vitamins, iron and calcium that are otherwise rich in wheat products. [6]
So Why Are Gluten-Free Diets So Popular?
According to Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing, the popularity relates to a combination of factors [7], including:
Intuition – It just seems like a good idea.
Logic – If gluten is bad for people with celiac disease, maybe it's bad for me.
Celebrity endorsement – If eliminating gluten is encouraged by someone I admire, maybe I should give it a try.
Anecdote – Testimonials can be powerful. Hearing about someone with bothersome symptoms that finally went away after eliminating gluten is difficult to ignore.
Marketing – Never underestimate the power of persuasion. Those selling gluten-free products or books about gluten-free diets can be convincing even if there's little science to back it up.
Pay attention to FODMAPs
Sometimes it's not the gluten that's bothering people, but other sugars found in wheat. An alternative hypothesis suggests that people who say their symptoms improve on a gluten-free diet may actually be reacting to another set of carbohydrates in wheat called FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols). However, research on this is in the very early stages. Many of the studies involving people with gluten sensitivity or FODMAPs diets are tiny so further research is needed.
Before you try a gluten-free diet…
There is no evidence that a gluten-free diet benefits anyone but those with celiac disease and those who are gluten intolerant. Gluten-free diets are not healthier and do not contain more or better nutrients. Many gluten-free products contain extra additives to make them palatable. Because of the potential harm — and unknown benefit — of recreational gluten avoidance, researchers who work in this area advise people to think twice before going gluten free (unless, of course, they have celiac disease or a diagnosed allergy). [8]
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