Nthawi zambiri, ma nitrate samalumikizidwa ndi chakudya chamadzulo, koma amadzutsa malingaliro okhudza maphunziro a chemistry yakusukulu kapena feteleza. Ngati mumaganizira za nitrates muzakudya, chithunzithunzi cholakwika chomwe chimabwera m'maganizo ndi chakuti muzakudya zokonzedwa ndi masamba atsopano, nitrates ndi mankhwala oyambitsa khansa. Koma kodi kwenikweni ndi chiyani ndipo nthawi zonse zimakhala zovulaza?
M'malo mwake, kulumikizana pakati pa nitrites/nitrates ndi thanzi ndizowoneka bwino kuposa "ndizoipa kwa ife". Mwachitsanzo, kuchuluka kwa nitrate yachilengedwe mumadzi a beetroot kumalumikizidwa ndi kutsika kwa magazi komanso kuchuluka kwa magwiridwe antchito athupi. Nitrates ndizomwe zimagwiritsidwa ntchito mu mankhwala ena a angina.
Kodi nitrates ndi nitrites ndi zoyipa kwa ife?
Nitrates ndi nitrites, monga potassium nitrate ndi sodium nitrite, mwachibadwa zimachitika mankhwala mankhwala okhala nayitrogeni ndi mpweya. Mu nitrate, nayitrogeni amalumikizidwa ku maatomu atatu a oxygen, ndipo mu nitrites, mpaka awiri. Zonsezi ndi zoteteza mwalamulo zomwe zimalepheretsa mabakiteriya owopsa mu nyama yankhumba, ham, salami, ndi tchizi.
Koma kwenikweni, pafupifupi 5% yokha ya nitrates muzakudya zaku Europe zomwe zimachokera ku nyama, kuposa 80% kuchokera ku masamba. Masamba amapeza ma nitrates ndi nitrites kuchokera ku dothi lomwe amamera. Nitrates ndi mbali ya mchere wachilengedwe, pamene nitrites amapangidwa ndi tizilombo toyambitsa matenda timene timaphwanya nyama.
Zobiriwira zamasamba monga sipinachi ndi arugula zimakonda kukhala mbewu zapamwamba za nitrate. Magwero ena olemera ndi udzu winawake ndi madzi a beetroot, komanso kaloti. Zamasamba zomwe zimabzalidwa mwachilengedwe zimatha kukhala ndi milingo yotsika ya nitrate chifukwa sagwiritsa ntchito feteleza wa nitrate.
Komabe, pali kusiyana kwakukulu pakati pa malo a nitrates ndi nitrites: nyama kapena masamba. Izi zimakhudza ngati ali ndi khansa.
Kuyanjana ndi khansa
Nitrates eni ake amakhala osakhazikika, zomwe zikutanthauza kuti sangatengeke ndi zochitika zamagulu m'thupi. Koma ma nitrites ndi mankhwala omwe amapanga amakhala otakataka kwambiri.
Ma nitrites ambiri omwe timakumana nawo samadyedwa mwachindunji, koma amasinthidwa kuchokera ku nitrates ndi mabakiteriya mkamwa. Chochititsa chidwi n'chakuti, kafukufuku amasonyeza kuti kugwiritsa ntchito mankhwala otsekemera pakamwa kungachepetse kupanga nitrite pamlomo.
Ma nitrites opangidwa mkamwa mwathu akamezedwa, amapanga nitrosamines m'malo a acidic a m'mimba, ena mwa omwe amakhala oyambitsa khansa ndipo amalumikizidwa ndi khansa ya m'matumbo. Koma zimenezi zimafuna gwero la ma amine, mankhwala opezeka ochuluka m’zakudya zomanga thupi. Ma nitrosamines amathanso kupangidwa mwachindunji muzakudya pophika pa kutentha kwambiri, monga kukazinga nyama yankhumba.
"Nitrates/nitrites omwe ali ndi khansa si ambiri, koma momwe amakonzekerera komanso malo awo ndi chinthu chofunikira. Mwachitsanzo, ma nitrites mu nyama yokonzedwa ali pafupi kwambiri ndi mapuloteni. Makamaka amino zidulo. Akaphikidwa pamalo otentha kwambiri, amawalola kupanga ma nitrosamines oyambitsa khansa mosavuta,” anatero Keith Allen, mkulu wa sayansi ndi ubale wa anthu wa World Cancer Research Foundation.
Koma Allen akuwonjeza kuti nitrites ndi chimodzi mwa zifukwa zomwe nyama yokonzedwa imathandizira khansa ya m'matumbo, ndipo kufunikira kwake sikudziwika. Zinthu zina zomwe zingathandizire ndi monga chitsulo, polycyclic onunkhira hydrocarbons omwe amapanga nyama yosuta, ndi ma heterocyclic amines omwe amapangidwa nyama ikaphikidwa pamoto wotseguka, womwe umapangitsanso zotupa.
Mankhwala abwino
Ma nitrites si oipa choncho. Pali umboni wokulirapo wa phindu lawo pamtima komanso kupitirira apo, chifukwa cha nitric oxide.
Mu 1998, asayansi atatu aku America adalandira Mphotho ya Nobel chifukwa cha zomwe adazipeza ponena za gawo la nitric oxide mu dongosolo la mtima. Tsopano tikudziwa kuti imakulitsa mitsempha ya magazi, imachepetsa kuthamanga kwa magazi, komanso imalimbana ndi matenda. Kukhoza kupanga nitric oxide kwagwirizanitsidwa ndi matenda a mtima, shuga, ndi erectile dysfunction.
Njira imodzi yomwe thupi limapangira nitric oxide ndi kudzera mu amino acid yotchedwa arginine. Koma tsopano zikudziwika kuti nitrates ingathandize kwambiri kupanga nitric oxide. Tikudziwanso kuti izi zitha kukhala zofunika kwambiri kwa okalamba, chifukwa kupanga kwachilengedwe kwa nitric oxide kudzera arginine kumachepa ndi ukalamba.
Komabe, ngakhale ma nitrate omwe amapezeka mu ham ali ofanana ndi omwe mungadye ndi saladi, zokhala ndi zomera ndizabwino kwambiri.
"Tidawona kuopsa kowonjezereka kokhudzana ndi nitrate ndi nitrite kuchokera ku nyama ya khansa zina, koma sitinawone kuopsa kokhudzana ndi nitrate kapena nitrite kuchokera kumasamba. Osachepera m'maphunziro owunikira omwe amamwa amawerengedwa kuchokera pamafunso odzipangira okha, "atero Amanda Cross, mphunzitsi wa matenda a khansa ku Imperial College London.
Cross akuwonjezera kuti ndi "lingaliro lomveka" kuti nitrates mu masamba obiriwira amakhala osavulaza. Izi ndichifukwa choti ali ndi mapuloteni ambiri komanso amakhala ndi zinthu zoteteza: vitamini C, polyphenols ndi ulusi womwe umachepetsa kupanga nitrosamine. Choncho pamene ma nitrate ambiri m’zakudya zathu amachokera ku ndiwo zamasamba ndipo nawonso amalimbikitsa kupanga nitric oxide, mwina amakhala abwino kwa ife.
Katswiri wina wa nitric oxide anapita patsogolo, akutsutsa kuti ambiri aife tilibe ma nitrates / nitrites ndipo ayenera kuikidwa ngati zakudya zofunikira zomwe zingathandize kupewa matenda a mtima ndi zikwapu.
Ndalama yoyenera
Ndikosatheka kuyerekeza modalirika kudya kwa nitrate chifukwa zakudya za nitrates zimasinthasintha. "Milingo imatha kusintha ka 10. Izi zikutanthauza kuti kafukufuku wofufuza zotsatira za thanzi la nitrate ayenera kutanthauziridwa mosamala kwambiri, chifukwa "nitrate" ikhoza kukhala chizindikiro cha zakudya zamasamba," anatero Günther Kulne, katswiri wa matenda okhudza matenda okhudza thanzi la University of Reading ku UK.
Lipoti la 2017 la European Food Safety Authority lidavomereza kuchuluka kwatsiku ndi tsiku komwe kumatha kudyedwa kwa moyo wonse popanda chiopsezo chathanzi. Ndilofanana ndi 235 mg wa nitrate kwa munthu wolemera makilogalamu 63,5. Koma lipotilo linanenanso kuti anthu amisinkhu yosiyanasiyana akhoza kupitirira chiwerengerochi mosavuta.
Kudya kwa nitrite nthawi zambiri kumakhala kotsika kwambiri (chiwerengero cha ku UK ndi 1,5mg patsiku) ndipo European Food Safety Authority inanena kuti kukhudzana ndi mankhwala oteteza nitrite kuli m'malire otetezeka kwa anthu onse ku Ulaya, kupatulapo kupitirira pang'ono. mwa ana omwe amadya zakudya zambiri zowonjezera.
Akatswiri ena amatsutsa kuti malipiro a tsiku ndi tsiku a nitrates / nitrites ndi akale, ndipo kuti milingo yapamwamba si yotetezeka, koma yopindulitsa ngati imachokera ku masamba osati nyama yokonzedwa.
Zapezeka kuti kudya kwa 300-400 mg wa nitrate kumalumikizidwa ndi kuchepa kwa kuthamanga kwa magazi. Mlingo uwu ukhoza kupezedwa kuchokera ku saladi imodzi yayikulu ndi arugula ndi sipinachi, kapena kumadzi a beetroot.
Pamapeto pake, kaya mukumwa poizoni kapena mankhwala zimatengera, monga nthawi zonse, pa mlingo. 2-9 magalamu (2000-9000 mg) a nitrate akhoza kukhala oopsa kwambiri, okhudza hemoglobin. Koma kuchuluka kwake ndikovuta kupeza nthawi imodzi ndipo n'zokayikitsa kwambiri kuti kungabwere kuchokera ku chakudya chokha, m'malo mochokera kumadzi oipitsidwa ndi feteleza.
Chifukwa chake, ngati muwapeza kuchokera kumasamba ndi zitsamba, ndiye kuti phindu la nitrates ndi nitrate pafupifupi limaposa zovuta zake.