Znanost protiv vegana: 4 najveće laži o mesu!
Prehrana

Znanost protiv vegana: 4 najveće laži o mesu!

Veganska prehrana vrsta je prehrane u kojoj osoba ne jede namirnice životinjskog porijekla. U objašnjenju prednosti veganske prehrane, uz mnoge moralne i ideološke razloge, navode se i "nezdravi učinci crvenog mesa" koje vegani ističu, podupirući tezu da je veganska prehrana "najbolja za ljudsko zdravlje".

Među tvrdnjama koje vegani ističu su:

  1. meso izaziva upalne procese zbog molekule Neu5Gc
  2. meso izaziva upalne procese zbog arahidonske kiseline
  3. konzumacija mesa vodi do razvoja srčanih bolesti
  4. meso je krivac za nastanak karcinoma

No, što znanost kaže o ovim navodima?

meso

1. Meso izaziva upalne procese zbog molekule Neu5Gc

Neu5Gc je molekula šećera koju nalazimo u mesu, a produkcija ove molekule je značajno smanjena u suvremenog čovjeka, nego što je to bilo u naših dalekih predaka. No, to i dalje ne sprječava neke koji ovu molekulu smatraju krivcem za razvoj mnogih upalnih procesa u organizmu. Prema toj tezi, kako postoji molekula Neu5Gc, tako postoje i antitijela za tu molekulu koja cirkuliraju u ljudskom organizmu. Molekula Neu5Gc nakon konzumacije mesa završava u našim tkivima, šaljući signal napada od strane tih antitijela u našem krvotoku što vodi do razvoja kroničnih upalnih procesa i bolesti.

No, da je ovo slučaj, tada bi kronični upalni procesi bili zabilježeni već u paleolitičkim vremenima, što nije slučaj. Također, s većom konzumacijom mesa, povećavala bi se i količina upalnih procesa u organizmu, što također nije slučaj. Upravo suprotno, niz je studija potvrdio da prehrana sa smanjenim udjelom ugljikohidrata, a povećanim unosom crvenog mesa smanjuje upalne procese u organizmu.

Osobe kojima je prehrana dominantna s crvenim mesom imaju slične rezultate upalnih markera kao oni koji imaju prehranu dominantno baziranu na ribi, koja je poznata kao snažna antiupalna hrana.

meso

2. Meso izaziva upalne procese zbog arahidonske kiseline

Prema protivnicima mesa u prehrani, arahidonska kiselina je drugi krivac pronađen u mesu odgovoran za razvoj upalnih procesa u organizmu. Arahidonska kiselina je dugolančana omega-6 masna kiselina koju se nalazi u polinezasićenim dijelovima mesa, a upravo je meso s visokim udjelom masti ono koje ima nizak udio ovih vrsta masnoća.

Osim toga, arahidonska kiselina koju nalazimo u mesu uvijek je praćena dugolančanim omega-3 masnim kiselinama - EPA i DHA koji su u balansu. Dakle, koncentracija ovih vrsta masti u tkivima nije pod utjecajem arahidonske kiseline, kao što je slučaj nakon konzumacije visokih doza polinezasićenih omega-6 masnih kiselina, što je tipično za osobe koje ne jedu meso ali unose biljna ulja i neživotinjske izvore proteina, poput orašastih plodova, sjemenki i grahorica.

Količina arahidonske kiseline koju se u organizam unese mesom pozitivno služi zdravlju stanične membrane i podržava antiupalni odgovor bez da ugrožava omega-3 masne kiseline te bez stvaranja okruženja sklonog upalama. Dokazano je, visoke razine omega-3 masne kiseline i arahidonske kiseline potiču najniže razine upalnih procesa.

Ovo je na tragu naših dalekih predaka koji su unosili hranu puno bogatiju arahidonskom kiselinom nego što je današnja prehrana, a koji su bili puno manje ugroženi upalnim procesima, nego što je suvremeni čovjek. Također, majčino mlijeko je bogato arahidonskom kiselinom, a poznato je da je to mlijeko namijenjeno za rast i razvoj djeteta, a svakako ne stvaranja upalnih procesa.

meso

3. Konzumacija mesa vodi do razvoja srčanih bolesti

Protivnici mesa u prehrani u potvrdi ove teze ističu studiju koja govori da se metabolizam aminokiseline l-carnitine u TMAO (trimetilamin N-oksid) ubrzava začepljenje krvnih žila. TMAO je metabolit koji nastaje od bakterija u crijevima, a njegove visoke razine su povezane s povećanim rizikom od razvoja srčanih bolesti stoji u drugoj tezi koju ističu vegani.

No, problem u gornjim studijama jest to što je prva napravljena na uzorku od 6 ljudi, a druga na miševima koji su dobivali l-carnitine.

Niz je relevantnijih studija koje potvrđuju da je razina TMAO puno veća u primjerice plodovima mora nego u crvenom mesu, a kako stoji u časopisu Food Chemical Toxicology, zdravlje crijeva je značajan faktor u razinama TMAO-a. Naime, čak iako TMAO povećava rizik od razvoja srčanih bolesti, povećane razine ovog metabolita u onih koji jedu crveno meso povezana je sa zdravljem osobe i općom kvalitetom hrane s epidemiološkog aspekta.

Povećan TMAO je rezultat poremećenog zdravlja crijeva, a krivce treba potražiti u brzoj hrani, gaziranim napitcima, povećanom unosu šećera i neaktivnom načinu života.

meso

4. Meso je krivac za nastanak karcinoma

Rasprava o odgovornosti mesa za nastanak različitih vrsta karcinoma često ide u takve krajnosti da se tvrdnja temelji na istraživanju u kojem se pod mesom koriste - hrenovke! Naravno da je nemoguće usporediti ovakve proizvode s kvalitetnim komadom crvenog mesa, pa su i rezultati takvih studija loši i nevjerodostojni.

Ono što se stavlja na teret mesu su dva spoja: heterociklički amini (HA) i policiklički aromatski ugljikovodici (PAH), koji nastaju kad se meso prepeče. Za njih je dokazano da potiču rast malignih stanica nekoliko studija provedenih na životinjama. No, valja imati na umu da ovih spojeva nastaje još i više ako se prepeče - povrće!

No, što god pekli, pazite da namirnicu ne prepečete već da bude pravilno termički obrađena, a ne izgorena. Dodatno, savjetuje se da se meso marinira nekoliko sati prije pripreme koristeći kisele sastojke poput octa. Naime, nekoliko studija pokazuje da ova praksa snižava rizik od nastanka ovih spojeva čak do nule.

Vegani će na teret često staviti i AGE (krajnje proizvode uznapredovale glikolizacije) tvrdeći da je to problem kod kuhanja mesa, no studije pokazuju da se visoke razine AGE-a zamjećuju i kod vegetarijanaca. Naime, interna proizvodnja AGE-a, pod utjecajem loše prehrane, puno je ozbiljniji problem od probave i apsorpcije. Naime, razlog tome je i to što meso uz AGE prirodno sadrži i njegove inhibitore, poput aminokiseline karnozin.

meso

Dodatno, kao krivac za razvoj karcinoma, vegani ističu i IGF-1, faktore hormona rasta. No, ako se pogleda šira slika i što IGF-1 radi u organizmu: sudjeluje u izgradnji kostiju, održava mišićno tkivo, održava zdrave razine ostalih hormona, sudjeluje u procesima topljenja masnog tkiva, jasno je da održavanje visoke razine ovog hormona treba biti prioritet, uz održavanje visokih razina drugih hormona koji primjerice sprječavaju pretilost i sarkopeniju (gubitak mišićne mase), poput testosterona.

Nedavno provedene studije pokazuju da kalorijske i proteinske restrikcije s ciljem dugovječnosti imaju puno više veze s balansom aminokiselina, nego s kalorijskim unosom. Studija je pokazala da miševi kojima je smanjen unos aminokiseline metionin (koju nalazimo u mesu, jajima i mliječnim proizvodima) bilježe ista smanjena u oksidativnom stresu i smrtnosti, a bez smanjenja kalorijskog unosa. Dodatno, miševi kojima je u prehranu dodana aminokiselina glicin (nalazimo je u kostima i vezivnim tkivima) bilježe ista poboljšanja.

Stoga, prema navedenom može se zaključiti da potencijalni benefiti u borbi protiv karcinoma nisu smanjenje količine mesa, već u prehrani bogatoj različitim dijelovima mesa, kako bi se iskoristio maksimalni potencijal ove namirnice u očuvanju zdravlja.

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Svi komentari na temu: Znanost protiv vegana: 4 najveće laži o mesu!

Svakom kako hoce,znanost je precijenjena i stalno u mijeni..pomisao na šok životinje koja je ubijena na vrlo ružan način,relativno svjesne tipa krave..jednostavno ne zelim tako nesto unositi u sebe.
gabrijela
14.01.17. u 11:45
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Cijenjena redakcijo i @Zoki, pretpostavljam da Vam je jasno kako i mnogi ljudi sa težim zdravstvenim problemima dolaze na ovu stranicu tražeæi SLAMKU spasa za sebe i zbog toga ovakvo pisanje mi zbilja izbaci osiguraè. Stoga bi bilo pohvalno da imate i bar MINIMUM etièke odgovornosti za sadržaj èlanaka, neovisno o napomeni da informacije na stranici ne služe za lijeèenje, xyz, itd... Ovo što je ovdje našvrljano, je iskrivljena znanost i selektivno biranje informacija u cilju senzacionalizma, koja nažalost samo još jednom dokazuje da najviše gluposti u svijetu piše na fitnes i nadrilijeènièkim portalima. Vrste upala kao i njihovi uzroci tj korjeni, od genetike pa nadalje do xyz vrsta poremeæaja uslijed naèina života, je bezbroj, pa je bezbroj i preporuèene prehrane a ne ovako bedasta besmislena simplifikacija. Nekom je zdravije sa manje mesa, nekome sa više, i zaista je kod velikog broja upala preporuka za crveno meso koje sadrži i zasiæene masnoæe svega par puta tjedno, tj svedeno na minimum, i uglavnom samo kuhano. Nisu u pravu ni vegani, ni mesojedi, jednostavno zbog èinjenice da smo svi razlièiti, pa tako i osjetljivi na razlièite stvari.
Pojma nemam tko piše ovakve èlanke, navedena autorica ili netko piše samo u njeno ime, ali veæ navod "Upravo suprotno, niz je studija potvrdio da prehrana sa smanjenim udjelom ugljikohidrata, a poveæanim unosom crvenog mesa smanjuje upalne procese u organizmu." je glupost, jer postoji veoma mali broj bolesti, upala i poremeæaja gdje je poveæana konzumacija mesa zdravija od poveæana konzumacije povræa i smanjenog mesa u prehrani.
Dodatno, èinjenica da usporeðuje meso( što je NAMIRNICA) sa ugljikohidratima(što je MAKRONUTRIJENT a ne namirnica) govori o totalnom neznanju i da ne zna ni google artikle protumaèiti. Mogla je bar razdvojiti rafinirane ugljikohidrate kao šeæer, fruktoze kao sladila u piæima, itd.(koji nekima zaista mogu biti štetni), , od ugljikohidrata u voæu i povræu, kad je veæ radila razliku izmeðu komada mesa i hrenovke. A u bilo kojoj novijoj knjizi ili sveuèilišnom udžbeniku o klinièkoj prehrani(nažalost nema ih prevedene na HR) je veæ dovoljno reèeno na ovu temu. Za BOLESNE ili one koji spadaju u riziène skupine, ovo nije stvar odabira nego preživljavanja, i krajnje je NEODGOVORNO na ovaj naèin pisati, pa sad neka netko npr sa hroniènom upalom gušteraèe sad navali na meso i nakon x godina umjesto da se izljeèi veæa je vjerojatnost da æe umrijeti u teškim bolovima. Tako da jest istina da crveno meso može imati nezdrave uèinke koji nisu navedeni, ali i pojedina povræa ili preraðevine za nekog mogu biti štetne.
   Kao i o temi kalorijske restrikcije kao produljavanja zdravog ili opæenito životnog vijeka, gdje autor-ica opet pokazuje totalno nepoznavanje, jer je bit u restrikciji kalorija a ne nutrijenata( pojednostavljeno- znaèi uglavnom konzumacija niskokaroriènih ali nutritivno bogatih namirnica), i periodièno može biti itekako korisna i restrikcija proteina, zbog stimuliranja jedne vrste autofagije(jer ih ima više) za razgradnju beskorisnih a moguæe i štetnih velikih molekula proteina u æelijama na aminokiseline, koje tijelo može opet iskoristiti za sintezu proteina, znaèi tijelo je dovoljno pametno da po potrebi radi i recikliranje proteina. Smanjen unos proteina inducira autofagiju tj razgradnju štetnih i nepotrebnih proteina unutar æelije, a time smanjuje i vjerojatnost nastanka mnogih bolesti. Na kraju krajeva je i Nobelova nagrada iz medicine i fiziologije dodijeljena baš za istraživanja autofagije. No besmisleno je ovdje nabrojati sve, ali oko usporavanja starenja ima veæ dosta utvrðenih èinjenica, pored raznih teorija i hipoteza koje su u fazi ispitivanja. Potvrðena èinjenica je i da mTOR putanja koju bodibilderi i autorica obožavaju, ubrzava starenje dok AMPK putanja usporava,( pa vježbajte naravno jer mišiæi luèe miokine potrebne za cjelokupno zdravlje, ali sa mjerom tj nemojte se ubijati, ili ubacite periode laganog treninga). Umjesto par istraživanja i googlanja, bi bilo korisnije proèitati malo literature, koje objašnjavaju što jest prihvaæena èinjenica a što samo hipoteza, na ovu temu npr Cell Aging: Molecular Mechanisms and Implications for Disease, ili koju noviju npr iz 2017, Biology of Aging.
Samo kao zanimljivost, prvu knjigu na temu kalorijske restrikcije i zdravlja je napisao talijanski filozof Luigi Cornaro, u 83.godini života cca 1540. godine. Bio je poznat po tome što je jeo malo i samo birane namirnice, a doživio je u to doba izuzetno rjetkih 98 godina.
   
U forumu svi povremeno lupetamo, ali ovako pisati èlanke na naslovnici kojima velikom broju bolesnih možete život upropastiti je BEsramno neodgovorno. Meni osobno ne smetaju, jer znam dovoljno da se nasmijem na bedastoæu, ali najveæi broj zdravstveno ugroženih nažalost ne zna,, pa ako povjeruju u èlanak samo kažemo "TKO im je kriv? " Ili ?
    Pa dajte molim vas da o temama koje se tièu zdravlja piše netko tko bar ima pojma o tome, ili nemojte pisati takve teme. Osim toga, autorica bi mogla jednom nauèiti da postoji razlika izmeðu njenih omiljenih "studija" i znanstveno prihvaæenih èinjenica, studije se provode na razlièitim skupinama ljudi, tako da se ne može poistovjetiti rezultat, kao ni rizièni faktori, i pojedinaène studije skoro ništa ne znaèe. Tako je i u èlanku o zasiæenim masnoæama usporedila meta analizu(koju je znanstveni svijet popljuvao) sa opservacijskim studijama u zadnjih 50 godina koje èinjenièno dokazuju faktore rizika kod kardiovaskularnih bolesnika. Ovaj èlanak se ne bazira nimalo na znanosti, nego ISKRIVLJENOJ selektivnoj interpretaciji znanosti i senzacionalizmu.
   
iver
15.01.17. u 19:19
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Pozdrav Iver, hvala na konstruktivnom komentaru. Članak je inspiriran člankom s T-nationa. Sve koje zanima ova tema, uz ovaj naš članak, preporučamo da podrobnije prate ovu temu kroz sve medije.
Zoki
17.01.17. u 09:08
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Puno je ovdje ne istina. Naši bake, djedovi, prabake itd. se nisu hranili kao što se većina ljudi hrane danas. Tada je meso bilo 'luksuz'... jelo se jednom u tjedan dana, a ne kao danas 1kg mesa dnevno..a da ne pričam o benefitima biljne prehrane, zato su ljudi i živjeli duže nego što žive danas.
rubi_
17.01.17. u 14:45
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Ne znam da li ovdje rade linkovi na web stranice, pa ću vrlo pojednostaviti priču. Ukucajte u Google "annual meat consumption", stavite pretragu na slike, a zatim "global cancer footprint", pa usporedite ih, vidjet ćete da se gotovo savršeno poklapaju 😆 Konzumacija mesa u svijetu i stooa raka se savršeno prate! Ako vam to nije dovoljan dokaz, ukucajte China study i American Institute For Cancer Research i pročitajte službeni stav Američkog Instituta za Istraživanje Raka gdje će vam reći da je konzumiranje životinjskih proizvoda uzrok ne samo raka, već i brojnih drugih bolesti poput dijabetesa, ateroskleroze, osteoporoze, pretilosti itd. da ne vjerujete industrijama i studijama koje pokušavaju zbuniti javnost, i da je to dokazano "in study after study, year after year". Ljudsko probavilo nije stvoreno za probavu mesa. Dk je crijevo mesoždera relativno kratko (3 dužine tijela) i glatko iznutra, ljudsko crijevo je 12 puta duže od tijela te duboko obavijeno i naborano. Kako nema vlastita vlakna, meso se prilično teško miče kroz dugo, smotano ljudsko probavilo. Prije nego stigne do kraja probavnog trakta postaje trulo i otrovno za organizam. P.S. nemojte više lagat ovaj napaćeni narod. Lijepi pozdrav! 😆✋
Zoki2
17.01.17. u 15:03
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Poštovana autorice teksta stiže korisna nadopuna znanja. Vrijedi pročitati i formirati ispravnije mišljenje. (by Vegan BB/Nutrition; Snaga Bilja FB) Pozdrav! OSVRT na: https://www.t-­nation.com/diet-­fat-­loss/10-­things-­vegetarians-­get-­wrong Claim #1 – Saturated fat does not clog arteries. T-­Nation: “2009 review in American Journal of Clinical Nutrition analyzed research from 21 studies with saturated fat intake from 350,000 people and found no association with heart disease.” The study being cited is http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824152/ “A meta-­analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat.” The cited study was published in 2009, but a 2012 Cochrane review found a different outcome. “This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14%.” In studies examining fat modification (not reduction of total intake, but switching fats in the diet), a reduction in CVD events was observed, but effects on mortality were unclear. The analysis is limited by few studies examining reduced vs modified fat intakes. http://www.ncbi.nlm.nih.gov/pubmed/22592684 SFA affect the arterial wall and may promote stiffness in arteries due to low-­grade inflammation. The anti-­inflammatory potential of HDL is reduced after consumption of saturated fat-­containing meals, impairing function of the arterial endothelial cells. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2878127/ http://www.ncbi.nlm.nih.gov/pubmed/15580061 http://www.ncbi.nlm.nih.gov/pubmed/16904539 Counseling families to feed children low saturated fat diets results in lower rates of metabolic syndrome as teenagers and young adults (up to 20 years old). http://www.ncbi.nlm.nih.gov/pubmed/25605660 Also, see point #4 about other adverse health outcomes associated with saturated fats. Claim #3 – Processed meats are not as healthy as unprocessed meats. The reference list on T-­Nation includes this study from the European Prospective Investigation into Cancer and Nutrition (EPIC study). http://www.ncbi.nlm.nih.gov/pubmed/23497300 “After multivariate adjustment, a high consumption of red meat was related to higher all-­ cause mortality (hazard ratio (HR) = 1.14, 95% confidence interval (CI) 1.01 to 1.28, 160+ versus 10 to 19.9 g/day), and the association was stronger for processed meat (HR = 1.44, 95% CI 1.24 to 1.66, 160+ versus 10 to 19.9 g/day). After correction for measurement error, higher all-­cause mortality remained significant only for processed meat (HR = 1.18, 95% CI 1.11 to 1.25, per 50 g/d). We estimated that 3.3% (95% CI 1.5% to 5.0%) of deaths could be prevented if all participants had a processed meat consumption of less than 20 g/day. Significant associations with processed meat intake were observed for cardiovascular diseases, cancer, and 'other causes of death'. The consumption of poultry was not related to all-­cause mortality.” There is evidence that processed red meats are associated with CVD, whereas red meats in other forms (not processed) are not as well associated with CVD. http://www.ncbi.nlm.nih.gov/pubmed/24932617 http://circ.ahajournals.org/content/121/21/2271.full Claim #4 – PUFA are associated with heart disease, but SFA are not. The first part is not in line with the current evidence. For the second part, see point #1. Replacement of SFA with PUFA for at least a year results in less CHD (myocardial infarction and/or cardiac death) risk, and longer duration increases benefits. When subjects ate 8-­21% of energy from PUFA, the pooled risk reduction was 19% compared to subjects eating 4-­6% of energy from PUFA. This corresponds to a 10% reduction in CHD risk for each 5% increase in PUFA consumption. http://www.ncbi.nlm.nih.gov/pubmed/20351774 “Convincing evidence was found that partial replacement of saturated fat (SFA) with polyunsaturated fat (PUFA) or monounsaturated fat (MUFA) lowers fasting serum/plasma total and LDL cholesterol concentrations… Furthermore, there was convincing evidence that partial replacement of SFA with PUFA decreases the risk of CVD, especially in men." http://www.ncbi.nlm.nih.gov/pubmed/25045347 “Furthermore, there was convincing evidence that partial replacement of SFA with PUFA decreases the risk of CVD, especially in men. This finding was supported by an association with biomarkers of PUFA intake;; the evidence of a beneficial effect of dietary total PUFA, n-­6 PUFA, and linoleic acid (LA) on CVD mortality was limited suggestive. Evidence for a direct association between total fat intake and risk of T2DM was inconclusive, whereas there was limited-­ suggestive evidence from biomarker studies that LA is inversely associated with the risk of T2DM.” Note that LA is an essential fatty acid and is found in plants. http://www.ncbi.nlm.nih.gov/pubmed/25045347 There may be specific SFA associated with disease risk. For CVD, palmitic and myristic acids were shown to be adversely associated with CVD risk factors in Alaskan Natives. For diabetes, higher circulating levels of palmitic and stearic acids in blood are associated with greater risk. http://www.ncbi.nlm.nih.gov/pubmed/26274054 http://www.ncbi.nlm.nih.gov/pubmed/25527759 Higher SFA intake is associated with reduced bone mineral density, particularly in men. http://jn.nutrition.org/content/136/1/159.full Over-­feeding SFA palmitic acid produced more weight gain in visceral adipose and liver fat compared to PUFA linoleic acid. “Both groups gained similar weight. SFAs, however, markedly increased liver fat compared with PUFAs and caused a twofold larger increase in visceral adipose tissue than PUFAs. Conversely, PUFAs caused a nearly threefold larger increase in lean tissue than SFAs. Increase in liver fat directly correlated with changes in plasma SFAs and inversely with PUFAs.” http://diabetes.diabetesjournals.org/content/63/7/2356.long There are other studies suggesting that other types of fats are more harmful than SFA, such as trans fat. “Saturated fats are not associated with all cause mortality, CVD, CHD, ischemic stroke, or type 2 diabetes, but the evidence is heterogeneous with methodological limitations. Trans fats are associated with all cause mortality, total CHD, and CHD mortality, probably because of higher levels of intake of industrial trans fats than ruminant trans fats.” http://www.ncbi.nlm.nih.gov/pubmed/26268692 Claim #5 – Lineolic acid is the dominant at in vegetable oil, and consumption is linked to tumor growth. Conjugated lineolic acid found in animal fat has proven effective in preventing cancer. Lineolic acid (LA) is not associated with tumor growth or CVD (see above). “Large scale human epidemiological studies indicate that high intakes of linoleic acid protect against the development of cancer.” http://www.ncbi.nlm.nih.gov/pubmed/9561154 “We reviewed the epidemiologic and experimental literature on linoleic acid intake and cancer risk and performed additional meta-­analyses of risk estimates from case-­control and prospective cohort studies. None of the combined estimates from within-­population studies indicated a significantly increased risk of cancer with high compared with low intakes of linoleic acid or polyunsaturated fat.“ http://ajcn.nutrition.org/content/68/1/142.abstract “It seems that no consistent result was observed even in similar studies conducted at different laboratories, this may be due to variations in age, gender, racial and geographical disparities, coupled with type and dose of CLA supplemented. Thus, supposed promising results reported in mechanistic and pre-­clinical studies cannot be extrapolated with humans, mainly due to the lack of inconsistency in analyses, prolonged intervention studies, follow-­up studies and international co-­ordination of concerted studies. Briefly, clinical evidences accumulated thus far show that CLA is not eliciting significantly promising and consistent health effects so as to uphold it as neither a functional nor a medical food. “ http://www.ncbi.nlm.nih.gov/pubmed/25972911 Claim #8 – Vegans and vegetarians do not have lower rates of disease. T-­Nation mentioned Seventh Day Adventists (generally vegetarian) and Mormons (not vegetarian) as study populations. Both groups tend to avoid smoking and alcohol use, allowing potential associations with other lifestyle factors like diet to be studied. They cited 22% lower cancer rate and 34% lower mortality rate from colon cancer in the Mormons compared to the general American population. It does appear Mormons have lower cancer rates and mortality rates compared to the general population. http://www.ncbi.nlm.nih.gov/pubmed/15904509 http://www.ncbi.nlm.nih.gov/pubmed/17920112 http://www.ncbi.nlm.nih.gov/pubmed/6933238 Mormons were examined in a study looking at the connection between families and cancer risk. Familial factors were implicated in a substantial portion of cancer risk. http://www.ncbi.nlm.nih.gov/pubmed/15779016 Mormons also have lower rates of cardiovascular disease deaths. http://www.ncbi.nlm.nih.gov/pubmed/727204 “Accordingly, mortality rates of Mormons and Seventh-­day Adventists show a significant lower level when compared with cancer data of lung, colon and rectum, and prostate from the best German cancer registry (Saarland). Some tumor rates are higher in Mormons, e.g. malignant melanoma, also all types of malignant lymphoma and myeloma. The life expectancy is generally elevated by 2-­4 years in Mormons and Seventh-­day Adventists.” http://www.ncbi.nlm.nih.gov/pubmed/1449267 T-­Nation: “Despite the Seventh Day Adventists' low rate of colorectal cancer, they seem to be at a higher risk of other cancers – Hodgkin's disease, malignant melanoma, brain, skin, uterine, prostate, endometrial, cervical, and ovarian cancer.” The Adventist Health Studies in America started in 1960 and are still ongoing today. The initial study in 1960-­1965 showed Adventists had 60-­76% lower death rates from all cancers, and reduced incidence of lung, colorectal, and breast cancers, and lower coronary heart disease. The second study in 1974-­1988 identified several dietary factors that were associated with reduced risk of heart disease and select cancers. The third study started in 2002. The studies are summarized here: http://publichealth.llu.edu/adventist-­health-­studies In Danish Adventists, lower rates of cancer in the lung, buccal cavity, liver, cervix, rectum, and stomach were observed in a 2012 study. http://www.ncbi.nlm.nih.gov/pubmed/22910035 The rates of various cancers in vegetarians (vegetarian, pesco-­vegetarian, vegan, and other categories) are well organized here, including the Adventist, EPIC-­Oxford, and other similar studies: http://www.veganhealth.org/articles/cancer There are lower rates of all cancers in vegetarians, plus lower incidence of the several specific cancers in vegetarians, including colorectal, prostate, breast, stomach, pancreatic, brain (meningioma), oral, bladder, and lymphatic & hematopoietic tissues (non-­Hodgkin’s lymphoma, multiple myeloma). Not all studies separated vegans from other types of vegetarians, but it appears that not consuming meat provides a reduction in cancer risk. Looking at this data, I would venture that the avoidance of smoking and alcohol use is likely a large contributor to the health outcomes measured. The connection between smoking and cardiovascular disease risk is well established, and there is also data on alcohol use and cancer risk. Another factor to consider is that Adventists emphasize maintaining a healthy body weight, and adiposity/obesity is associated with cancer risk. Vegetarians have a significant difference in BMI from non-­vegetarians in the Adventist studies. “The 5-­unit BMI difference between vegans and nonvegetarians indicates a substantial potential of vegetarianism to protect against obesity. Increased conformity to vegetarian diets protected against risk of type 2 diabetes after lifestyle characteristics and BMI were taken into account. Pesco-­ and semi-­vegetarian diets afforded intermediate protection." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2671114/ More on BMI and cancer risk, alcohol and cancer risk http://www.nhlbi.nih.gov/health/health-­topics/topics/smo http://circ.ahajournals.org/content/96/9/3243.full http://www.cancer.gov/about-­cancer/causes-­prevention/risk/alcohol/alcohol-­fact-­sheet http://www.cancer.gov/about-­cancer/causes-­prevention/risk/obesity/obesity-­fact-­sheet Claim #9 – Vegetarians do not live longer. T-­Nation: “Research from 1973 in the American Journal of Epidemiology found higher all-­cause mortality rates in both vegetarian men (0.93%) and women (0.86%) compared to their non-­ vegetarian counterparts (men 0.89%, women 0.54%).” I cannot find a study about vegetarian mortality in the American Journal of Epidemiology’s archive for 1973. The first study that comes up in the search feature is a 1974 paper that shows vegetarians have lower blood pressure. Vegetarian mortality is about half that of the study populations in several large studies. http://www.veganhealth.org/articles/dxrates Emphasizing a more plant-­based diet (without having people commit to veganism) appears to offer protection in the PREDIMED study. http://ajcn.nutrition.org/content/100/Supplement_1/320S.long A recent meta-­analysis using 7 studies containing nearly 125,000 people found lower mortality, disease, and cancer in vegetarians. “Seven studies with a total of 124,706 participants were included in this analysis. All-­ cause mortality in vegetarians was 9% lower than in nonvegetarians (RR = 0.91;; 95% CI, 0.66-­ 1.16). The mortality from ischemic heart disease was significantly lower in vegetarians than in nonvegetarians (RR = 0.71;; 95% CI, 0.56-­0.87). We observed a 16% lower mortality from circulatory diseases (RR = 0.84;; 95% CI, 0.54-­1.14) and a 12% lower mortality from cerebrovascular disease (RR = 0.88;; 95% CI, 0.70-­1.06) in vegetarians compared with nonvegetarians. Vegetarians had a significantly lower cancer incidence than nonvegetarians (RR = 0.82;; 95% CI, 0.67-­0.97).” http://www.ncbi.nlm.nih.gov/pubmed/22677895 If vegetarians have lower mortality rates, they are likely living longer. J http://ajcn.nutrition.org/content/78/3/526S.long Many of the groups known for their longevity emphasize plant-­based diets, not necessarily vegan diets. There are potential mechanisms for longevity extension in plant-­based diets – methionine restriction, reduction of IGF-­1, lower energy intakes (calorie restriction), and antioxidant consumption. Plant proteins are lower in methionine content than animal proteins. http://www.ncbi.nlm.nih.gov/pubmed/18789600 http://www.ncbi.nlm.nih.gov/pubmed/12699704 http://www.ncbi.nlm.nih.gov/pubmed/23454735 http://www.ncbi.nlm.nih.gov/pubmed/24291541 http://www.ncbi.nlm.nih.gov/pubmed/10696634 http://www.ncbi.nlm.nih.gov/pubmed/17299498 Claim #12 – The brain needs saturated fat and cholesterol, and lower levels of these lipids are associated with cognitive impairment, Alzheimer’s, and Parkinson’s. T-­Nation mentions that breast milk contains high amounts of saturated fat to nourish our developing brains, and that brain support from cholesterol is one reason why cholesterol levels increase as we age. In general, higher saturated and trans fat intakes are associated with reduced cognition. This appears to be related to the hippocampus, and not the frontal cortex. http://www.ncbi.nlm.nih.gov/pubmed/23291218 http://www.ncbi.nlm.nih.gov/pubmed/22023100 http://www.ncbi.nlm.nih.gov/pubmed/21167850 Saturated fats may increase neurodegenerative responses to dietary copper. http://www.ncbi.nlm.nih.gov/pubmed/16908733 There is evidence that high fat diets are associated with inflammation in the brain, including in the hypothalamus before weight gain is apparent. http://diabetes.diabetesjournals.org/content/62/8/2629.full http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0005045 http://www.ncbi.nlm.nih.gov/pubmed/24075847 (in rodents) Studies in rodents suggest the mechanism is a transfer of inflammatory signals from the gut to the hypothalamus through the nodose ganglion. http://www.sciencedirect.com/science/article/pii/S0006291X15303272 We are unable to do experiments where we try to give people neurodegenerative diseases, but observational studies and rodent models suggest that dietary fat, particularly saturated and trans fat, are associated with the development of neurodegenerative diseases. Review of human observational studies: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4107296/ http://www.ncbi.nlm.nih.gov/pubmed/24916582 Insulin resistance is associated with Alzheimer’s. See above for discussion on various SFA and diabetes. http://www.ncbi.nlm.nih.gov/pubmed/26159189 http://www.ncbi.nlm.nih.gov/pubmed/26003667 http://www.ncbi.nlm.nih.gov/pubmed/24998414 http://www.ncbi.nlm.nih.gov/pubmed/23790682 It appears that high fat diet promotes Alzheimer’s, potentially independently of tau and amyloid protein pathways. (These are the proteins that form tangles/clusters in AD brains that can cause symptoms.) http://www.ncbi.nlm.nih.gov/pubmed/24269929 http://www.ncbi.nlm.nih.gov/pubmed/24630364 http://www.ncbi.nlm.nih.gov/pubmed/24205258 Claim #13: Consumption of animal foods increased human brain size. T-­Nation: “The incorporation of increasingly greater amounts of animal products into the diet was essential in the development of the large human brain.” – Aiello and Wheeler, Current Anthropology, 1995 While the inclusion of calorie-­rich animal foods likely did contribute to development of the human brain, there are other contributors as well, including cooking and social interaction. Cooking increases the available calorie content of food, and also makes some nutrients more bioavailability. The combination of modest amounts of animal foods and cooking (both plants and meat) produced a shift in calorie intake to support brain development. “Mechanisms contributing to energy being gained from cooking include increased digestibility of starch and protein, reduced costs of digestion for cooked versus raw meat, and reduced energetic costs of detoxification and defence against pathogens. If cooking consistently improves the energetic value of foods through such mechanisms, its evolutionary impact depends partly on the relative energetic benefits of non-­thermal processing methods used prior to cooking.” http://www.ncbi.nlm.nih.gov/pubmed/19732938 “This limitation was probably overcome in Homo erectus with the shift to a cooked diet. Absent the requirement to spend most available hours of the day feeding, the combination of newly freed time and a large number of brain neurons affordable on a cooked diet may thus have been a major positive driving force to the rapid increased in brain size in human evolution.” http://www.ncbi.nlm.nih.gov/pubmed/23090991 “These changes in diet and foraging behavior did not turn our hominid ancestors into carnivores;; however, the addition of modest amounts of meat to the diet combined with the sharing of resources that is typical of hunter-­gatherer groups would have significantly increased the quality and stability of hominid diets. These changes in dietary quality appear to have been critical in promoting the rapid brain evolution seen with the evolution of H. erectus. While dietary change alone cannot explain the evolution of large hominid brains, a sufficiently high quality diet was probably necessary for supporting the increased energy demands of larger brains.” http://www.ncbi.nlm.nih.gov/pubmed/14527625 Processing social cues and interacting with others may have also helped drive human brain development, as time was available for more social interactions in early humans who were not foraging all day. "In the spirit of these objectives, we present here a new theoretical proposal, the Inferential Brain Hypothesis, whereby the human brain is thought to be characterized by a shift from perceptual processing to inferential computation, particularly within the social realm. This shift is believed to be a driving force for the evolution of the large human cortex." http://www.ncbi.nlm.nih.gov/pubmed/22459075 "Thus, humans have evolved towards increased collaboration and mutual support. This kind of evolutionary pressure may have provided the basis for the development of the human brain with its unique functions." http://www.ncbi.nlm.nih.gov/pubmed/23414685 "Focusing on recent research from nonhuman primates, we describe how the primate brain might implement social functions by coopting and extending preexisting mechanisms that previously supported nonsocial functions. This approach reveals that highly specialized mechanisms have evolved to decipher the immediate social context, and parallel circuits have evolved to translate social perceptual signals and nonsocial perceptual signals into partially integrated social and nonsocial motivational signals, which together inform general-­purpose mechanisms that command behavior." http://www.ncbi.nlm.nih.gov/pubmed/23754410
Ivana_SnagaBilja
17.01.17. u 23:30
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Poštovani, hvala vam svima na konstruktivnim odgovorima, komentarima i izražavanju mišljenja. Tema o kojoj sam pisala je svakako kontroverzna i očekivano izaziva različite stavove. Vjerujem da će dostupnost informacija svakome pomoći da se opredijeli želi li i u kojoj mjeri konzumirati meso.
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18.01.17. u 09:24
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Objavljeno: 13.01.2017
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Zorana Jagodić