Chakudya pa Ubongo
Daniel Fisher, 01 / 10 / 05
Kodi ndi mafuta onenepa kwambiri, okhudzana ndi shuga omwe timafuna kuti tikhale oledzera? Nazi zomwe kafukufuku waposachedwa wasayansi akutiuza.
Labu ku Brookhaven National Laboratory ku Long Island, Gene-Jack Wang akubaya overeative ndi yankho lokhala ndi ma radioactive ndikuwayika pamakina a positron-emissions tomography kuti awone momwe ubongo wawo umakhudzira chakudya. Ngati maphunziro a Dr. Wang asonyeza chilichonse, awona kuti mayeso a striatum, mtundu wa njira yolumikizirana mkati mwaubongo, ali ndi zolandilira zochepa za dopamine kuposa striatum ya munthu amene amadya bwinobwino. Wang wasonyeza kale kuti kungowona ndikununkhira kwa chakudya kumatha kuyambitsa kutulutsa kwa dopamine, neurotransmitter yokhudzana ndi chidwi komanso chisangalalo. Awonetsanso kuti omwe amakonda kugwiritsa ntchito mankhwala osokoneza bongo ali ndi vuto lomweli la ma dopamine receptors.
Kufufuza kwa PET kamene amatha kugwiritsa ntchito methamphetamine amasonyeza malo ochepetsedwa a mapulogalamu a dopamine omwe amafuna mankhwala ambiri kuti azisangalala.
http://www.forbes.com/forbes/2005/0110/063.html
Kufufuza kwa PET kwa wodwala wodwala kwambiri wodwalayo kumasonyeza kuti alibe vuto la dopamine receptors. Kodi chakudya chingakhale chofanana ndi mankhwala osokoneza bongo?
Onjezerani izo ndipo chiphunzitso chikuwonekera: Odya mopitirira muyeso amadya chakudya chochuluka kuposa momwe angapangire kuti kick kick ya dopamine-chifukwa chomwe chimakhalira ndi ma cokehead amakoka cocaine. “Amagwiritsa ntchito kudya monga njira yobwezera,” Anatero Wang, dokotala wophunzitsidwa ndi a Johns Hopkins yemwe adaphunzira zakumwa zosokoneza bongo kwazaka zopitilira khumi. Lingaliro la Wang silingatanthauze china chilichonse kupatula kuti mankhwalawa amabera maubongo omwewo omwe adasintha zaka mamiliyoni ambiri kuti alimbikitse anthu kupeza ndi kudya chakudya. Izi sizitanthauza kuti chakudya ndi mankhwala. Palibe amene adachokapo atapita kuzizira kozizira pa Big Macs, pambuyo pake.
Ndipo komabe kafukufuku wake ali ndi tanthauzo lowopsa kumakampani azakudya pomwe akukonzekera kuyimba kwamilandu yokhudza kusuta chifukwa chazovuta zakunenepa dzikolo. Ngati maloya atha kuwonetsa kuti zakudya zili ndi vuto losokoneza bongo, atha kunena kuti kudya mopitirira muyeso sichisankho koma kukakamiza. Ngati atha kutsata kukakamizidwa ndi zosakaniza zina monga mafuta kapena manyuchi a chimanga a high-fructose, atha kukhala ndi umboni wofanana ndi nikotini - opanga zinthu atha kusokoneza makasitomala awo pachakudya.
Dr.William Jacobs, wofufuza za kunenepa ku University of Florida anati: "Mungayambitse zinthu kukhala zosokoneza kwambiri. "Monga momwe kampani yaku Colombia idapangira crack cocaine."
Pakadali pano asayansi ali kutali kuti atulutse Fry yaku France yosuta. Palibe amene wapeza umboni wodalirika woti opanga akutenga mwayi pachinthu chobisika chomwe chimaposa chisankho, ngakhale anthu ena amaganiza kuti atsala pang'ono kukhazikitsa izi. Dr. Neal Barnard wa Physicians Committee for Responsible Medicine, wolemba buku la Breaking the Food Seduction St. Martin's Press, 2003), akuwonetsa kuti chokoleti imagwira ubongo ngati heroin. Ndipo tchizi, akuti, chimasanduka ma casomorphin omwe amatha kukhala osokoneza bongo. "Pali anthu omwe amalakalaka tchizi," akutero a Barnard, omwe amadya zamasamba omwe alinso m'gulu lomenyera ufulu wa nyama. "Zimangokhala ngati mankhwala osokoneza bongo."
Koma palibe chitsimikizo kuti ma casomorphins amalowa m'magazi a achikulire, ndikuwasandutsa kukhala zidole za Brie-gobbling. Ofufuza apeza umboni wina wosonyeza kuti zakudya zina zimapangitsa kuti dopamine azimasulidwa m'zinyama kuposa zina - zotsutsana ndi mfundo zalamulo zakuti zakudyazo ndizosokoneza bongo komanso zowopsa - koma zomwe apeza ndizovuta kapena ndizovuta kutengera anthu.
Ann Kelley wa yunivesite ya Wisconsin, Mwachitsanzo, zawonetsa kuti kupereka chokoleti chodzaza ndi kalori Onetsetsani kuti, makoswe amathandizira kuchepetsa makondomu omwe amachititsa kuti zisangalatse, zomwe zimawonekeranso mu makoswe omwe apatsidwa mankhwala osokoneza bongo. Zakudya wamba sizikhala ndi zotsatirapo zotere. "Tanthauzo lake ndikuti kudya mopitirira muyeso kwa zakudya zomwe zimakonda kwambiri kumatha kukhudza ubongo," akuti Kelley, yemwe ntchito yake imathandizidwa ndi gawo lomwe limapeza ndalama kuchokera ku PepsiCo, Procter & Gamble ndi ena opanga chakudya.
Ochita kafukufuku awona zikwangwani zakukonda ubongo wofananira ndi zakudya zokoma ndi zamafuta mwa anthu. Komabe, umboniwo siwodziwika bwino. Kelley adatsimikiza milingo yaubongo-endorphin pakupha ndikutulutsa makoswe; Kufufuza kwa PET ndi njira zina zosapha sizolondola.
Limodzi mwa maphunziro omwe atchulidwa kwambiri, ndi wofufuza ku University of Washington a Adam Drewnowski, adapeza kuti azimayi omwe adapatsidwa mankhwala omwe amaletsa opioid receptors amadya zakudya zochepa zokoma, zamafuta ambiri - koma pokhapokha ngati ali ndi bulimic. Alibe chifukwa chake mankhwalawa sanakhudze zakudya za anthu 12 olamulira bwino. Opioid blocker "imagwira ntchito, timawona," akutero. "Koma kokha mwa munthu yemwe machitidwe ake asokonezeka."
Kusatsimikizika konse uku ndikomveka, chifukwa cha zovuta zomwe zimayambitsa kudya ndi kunenepa kwambiri. Opanga mankhwala afunafuna pachabe kupeza mankhwala ozizwitsa omwe angapangitse anthu kuonda; ambiri, monga fen-phen ndi methamphetamines, amakhala ndi zovuta zoyipa kuposa vuto lomwe akuyesetsa kuthetsa. Acomplia ochokera ku Sanofi-Aventis amatseka ma cannabinoid receptors, ma brain receptors omwe amapatsa osuta mphika munchies, komanso amayambitsa kukhumudwa kwa odwala ena (FORBES, "The Ultimate Pill?" Dec. 13, 2004, p. 96).
Kunenepa kwambiri kumachitika m'mabanja - majini okha amatha kuneneratu mpaka 40% ya mwayi wokhala wonenepa kwambiri- ndipo kudya mopitirira muyeso kumawoneka kuti kumalumikizidwa ndi zovuta zina zokhudzana ndi mabanja monga uchidakwa ndi mankhwala osokoneza bongo. Zonsezi zimawoneka kuti zikuphatikiza zosokoneza muubwino wamaubongo, zomwe zimapereka chisangalalo mu dopamine poyankha machitidwe omwe amafalitsa monga kudya, kumwa madzi kapena kugonana. Omwe amamwa mankhwala osokoneza bongo a Cocaine, mwachitsanzo, amakhala ndi ma dopamine receptors ochepa chifukwa chothandizidwa ndi mankhwalawa - amaletsa onyamula omwe nthawi zambiri amatengera dopamine m'maselo aubongo kuti abwezeretsedwenso - kapena chifukwa adabadwa choncho.
Kuchokera ku Aroma kupita ku Appetite
1. Mimba yopanda kanthu imatulutsa ghrelin, chilakolako chofuna kudya, ku hypo-thalamus, yomwe imayang'anira kagayidwe kake ka thupi.
2. The hypothalamus imatulutsa dopamine ku nucleus accumbens ndi striatum, zomwe zimalimbikitsa chidziwitso cha ubongo kupeza chakudya.
3. Kununkhira kwa chakudya kumapangitsa kuti amygdala, komanso phokoso la maganizo, ndipo amachititsanso kuti dopamine amasulidwe ndi nucleus accumbens.
4. Kuwona, kununkhira ndi kulawa kwa chakudya kumayambitsa kutulutsa kwa endorphins (opioids) ndi dopamine ndi orbitofrontal cortex, zomwe zimapangitsa kuti ubongo uzidya.
5. Leptin yotulutsidwa ndi maselo a mafuta amatha kupitirira ghrelin ndipo imasonyeza kuti hypothalamus imatseka dopamine kutuluka. Chotsatira chake, chilakolako chimatha.
Odyera mopitirira muyeso ali ndi kuchepa kofananako kwa ma dopamine receptors, koma ofufuza sakudziwa ngati uku ndi kusiyana komwe adabadwa nako, komwe kumapangidwa ndikudya mopitilira muyeso kapena kuphatikiza awiriwo. Asayansi nawonso sakudziwitsanso kulumikizana pakati pa magawo odziyimira pawokha aubongo omwe amayang'anira kugwiritsa ntchito mphamvu tsiku ndi tsiku ndi momwe amagwiritsira ntchito, komanso ubongo wodziwa zomwe zimayendetsa machitidwe monga kuyenda mumsewu kukatenga bacon cheeseburger.
Kulemera kwa thupi kumayang'aniridwa makamaka ndi hypothalamus, kapangidwe ka pakati pa ubongo kamene kamakhala koyambirira kamene kagayidwe kamene kamakhala kosawerengeka. Wofufuza wa pa yunivesite ya Rockefeller Jeffrey Friedman wawerenga kuti kusalingana kwa ochepa monga 1,700 calories pachaka kudzatengera kulemera kapena kuperewera kwa nthawi. The hypothalamus imayankhula ndi ghrelin, hormone yotulutsidwa ndi chopanda kanthu m'mimba, mwa kumasula chilakolako-chochititsa chidwi cha m'mimba mwazigawo zina za ubongo. Amatsegula mavotiwa chifukwa cha leptin, mahomoni otulutsidwa ndi maselo ambiri.
Asayansi sakudziwabe momwe hypothalamus imalumikizirana ndi ubongo wam'mimba, tsamba lamalingaliro ozindikira, ngakhale amakhulupirira kuti dopamine imathandizira. Mwachitsanzo, mankhwala osokoneza bongo a fenfluramine, adalimbikitsa kutulutsidwa kwa dopamine mkati mwa hypothalamus ndipo anali ndi vuto lodetsa kudya. Hypothalamus imalumikizananso ndi kotekisi kudzera pa striatum ndi ma nucleus accumbens, kapangidwe kamene kamatulutsa dopamine yake ndi ma opioid poyankha chakudya (onani chithunzi).
Udindo weniweni wa ma nucleus accumbens ndichinsinsi. Zimayendetsa chidziwitso chakumva mkamwa ndi mphuno - wow, kuti pizza imanunkhira bwino! -Ndipo imatulutsa dopamine ndi ma opioid poyankha. Ochita kafukufuku awonanso kukonda zakudya zamafuta mosiyana ndi chakudya, chomwe sangathe kufotokoza. Onetsetsani kuti phokosolo limagwidwa ndi makoswe ndipo amadzikongoletsa pazinthu; perekani opioid blocker ndipo ayime. Nkhumba zouma popanda dopamine receptors mu nucleus accumbens mwamsanga amadzipezera okha njala mpaka kufa.
Ann Kelley wapeza mphamvu yolamulira kwambiri mu amygdala, likulu la malingaliro omwe amalumikizananso mitsempha yambiri ndi mphuno. Akachotsa amygdala mu makoswe ndi mankhwala omwe amaletsa kugwira ntchito, samakhalanso ndi nkhumba ngakhale ma nyukiliya awo atakulitsidwa. Zomwe akutanthauza, akuti, ndikuti kukhudzidwa kwa chakudya ndi zonunkhira zake - kumbukirani mbuluuli zomwe mudakhala nazo tsiku lanu loyamba? - zitha kukhala zofunikira kwambiri kuposa njira yochepetsera kulemera kwa hypothalamus. Cholinga chimodzi: Makampeni otsatsa omwe amakongoletsa zithunzi zakunyumba ndi moto atha kulimbikitsanso amygdala.
Zowona ndizakuti, ubongo wamunthu uli ndi njira zambiri zokulitsira chilakolako ndipo owerengeka okha ndiwo omwe amazimitsa. Izi ndizomveka m'mawu osinthika chifukwa mpaka pano anthu adakhalabe osowa chakudya nthawi zonse. "Taganizirani izi: Ubongo wanu ukuyenda kudutsa m'mayendedwe akuluakuluwa ndikunena kuti, 'Kodi sindine wosaka nyama? Nditha kugwira nsomba ya king salmon kapena ya Kobe popanda mwayi woti ndigwidwa ndi kambuku wamphongo wakuthwa, 'atero a Mark Gold, pulofesa wodziwika bwino wa sayansi ya ubongo ku McKnight Brain Institute ku University of Florida.
Funso lokhala ndi madola mabiliyoni ambiri ndiloti kaya zakudya zina zosavuta kugwiritsa ntchito zimatha kuyambitsa imodzi mwa njirazo kunena "idyani," ngakhale mbali zina za ubongo zikunena "zokwanira." Woyimira milandu Christopher Cole ku Washington ofesi ya Paul, Hastings Janofsky & Walker amalangiza makampani azakudya pazinthu zodzitchinjiriza milandu ikayamba. Pakadali pano sanawonepo kalikonse mu kafukufukuyu komwe angadandaule nako. Koma akuyang'anitsitsa magazini a kunenepa kwambiri: "Mukazindikira kuti [kunenepa kwambiri] ndi matenda ndipo mumanena kuti makampani akulimbikitsa anthu kuti atenge matendawa, mutha kupanga mlandu."