Vitamin E i starenie: chto menyaetsya posle 50 let
Vitamin E — eto kollektivnoe nazvanie vosmi zhirora stvorimykh soedineniy — chetyryokh tokofer olov i chetyryokh tokotrienolov, — iz kotorykh alfa-tokoferol yavlyaetsya naibolee aktivno podderzhivaemoy v tkanyakh cheloveka formoy. Po mere togo kak my perekachivaem za 50, ryad fiziologicheskikh izmeneniy vliyaet na kolichestvo usvaivayemogo vitamina E, effektivnost ego ispolzovaniya i ego znachenie dlya kletochnoy zashchity.
Okislitelny stress imeet tendentsiyu nakaplivatsya s vozrastom. Funktsiya mitokh ondriy stanovitsya mene effektivnoy, a balans mezhdu reaktivnymi formami kisloroda i antioksidantnoy zashchitoy mozhet skidyvatsya v nevygodnuyu storonu. Vitamin E, vstroyenny v kletochnye membrany, pomogaet preryvat tsepochki perekisnogo okisleniya lipidov do togo, kak oni povrezhday ut tselostnost membrany.
Svyazannye s vozrastom izmeneniya v usvoenii
Usvoenie vitamina E v tselom skhozhe u zdorovykh vzroslykh raznykh vozrastnykh grupp. Kak i vse zhiroras tvorimye nutrienty, ono zavisit ot dostatochnoy sekretsii zhelchi, aktivnosti pankr eaticheskoy lipazy i tselostnoy funktsii enterot sitov. U zdorovykh pozhilykh lyudey eti parametry rezko ne snizh ayutsya, no kumulyativny effekt rasprostr anennykh svyazannykh s vozrastom faktorov — snizh eniya potrebleniya zhira iz-za izmeneniy appetita, lekarstv, vliyayushchikh na peristaltics kishechnika, subklinicheskoy malabsorb tsii — mozhet neznachitelno snizit kontsentratsii tokoferola v krovi.
Issledovaniya pokazali, chto pozhilye vzroslye s nizkim potrebleniem pishchevogo zhira chashche imeyut nedostatochny status vitamina E — ne potomu, chto usvoenie samo po sebe narusheno, a potomu, chto nositel (pishchevoy zhir) nedostatoche n (Traber, 2006). Eto podcherkivayet tot zhe printsip, chto i u drugikh zhiroras tvorimykh vitaminov: dobavku sleduyet prinimat s soderzhashchey zhir edoy.
Doza i bezopasnost dlya pozhilykh
Dopustimyy verkhn iy uroven potrebleniya alfa-tokoferola dlya vzroslykh, ustanovl ennyy regulyatornymi organami, sostavlyayet 1000 mg v den (ekvivalentno 1500 ME natural nogo vitamina E). Bolshinstvo lyudey ne priblizh ayutsya k etomu porogy isklyuchitelno za schyot pishchi.
Odnako glavnoy proBlemoy bezopasnosti dlya pozhilykh yavlyaetsya vliyanie vysokikh doz vitamina E na svertyvaemost krovi. Vitamin E v dozakh vyshe primerno 400 ME v den mozhet podavlyat aggregatsiyu trombotsitov i meshat zavisimym ot vitamina K faktoram svyortyvaniya, uvelichivaya risk krovotecheniy (Traber, 2006). Eto priobretayet klinicheskoe znachenie u pozhilykh, u kotorykh uzhe mogut byt lomkie kapillyary ili kotorye prini mayut antikoagulyantny e preparaty.
Meta-analiz, izuchavshiy obshchuyu smertnost, obnaruzhil signal v storonu povyshennogo riska pri ochen vysokikh doza kh dobavok (vyshe 400 ME v den) u uzhe bolnykh populyatsy, khotya eti dannye ne byli vosproizvedeny v bolee zdorovykh ko gortakh (Miller et al., 2005). Prakticheskaya rekomendatsiya dlya pozhilykh — ostavatsya v predela kh 100–200 ME v den, esli vrach ne rekomendoval inoe.
BIOTECHUSA Vitamin E 100softgels — dostupny na maxfit.ee — predlagayet prostoy variant natural nogo vitamina E v forme myagkikh kapsul dlya stabilnogo usvoeni ya.
Vzaimo deystviya s lekarstvami
Pozhilye lyudi znachitelno chashche nahodya tsya na polipragmazii. Naibolee klinicheski znachimye vzaimo deystviya vitamina E:
- Antikoagulyant y (varfarin, apiksaban, rivaroksaban): Vitamin E mozhet potentsi rovit antikoagulyatsiyu, povyshaya risk krovotecheniya. Lyud i, prini mayushchie eti preparaty, ne dolzhny samostoyatelno prinimat vitamin E svykhe pishchevykh kolicheств bez meditsinskoy konsultatsii.
- Statiny: Nekotorye dannye in vitro svidetelstvuyut, chto antioksidant y, vklyuchaya vitamin E, mogut neznachitelno oslablyat povyshayushchy HDL effekt kombinatsiy niatsina so statistami, khotya klinicheskoe znachenie etogo osparivayetsya.
- Tamoksifen i drugie khimioterapevticheskie agenty: Antioksidanty v vysokikh dozakh teoreticheski mogut meshat okislitelnym mekhanizmam, ispolzuemym nekotorymi preparatami.
Vsegda soobshchayte lechashhemu vrachu ob ispolzovanii dobavok, osobenno pozhilym patsientam s neskolkimi sost oyaniyami.
Kogda prinimat dobavku
Priom vitamina E naibolee opravdan u pozhilykh lyudey, kotorye:
- imeyut dokumentirovannoe nizkoe potreblenie pishchevogo zhira ili sostoyaniya malabsorb tsii
- imeyut izmerenny nizky uroven alfa-tokoferola v syvorotke (nizhe primerno 12 mikromol/l)
- ne prini mayut antikoagulyant y ili drugie vzaimo deystvuyushchie preparaty
Dlya v ostalom zdorovykh vzroslykh starshe 50 let, pitayushchik hsya raznoobrazno i upotreblyayush chikh orekhi, semena, rastitelny e masla i zelenye ovoshchi, dobavka mozhet davat neznachitelny dopolnitelny efFekt pri tipichnykh pishchevykh dozakh. Reshenie luchshe vsego prinimat na osnove analiza krovi, esli eto vozmozhno.
Chasto zadavaemye voprosy
Pomogayet li vitamin E kozhe i pamyati u pozhilykh?
Vitamin E igraet rol v podder zhanii tselostnosti membrany kozhi i mozhet podderzhivat zdorovye nervnykh kletok. Odnako krupnye klinicheskie ispytaniya ne demonstrirovali ubedit elnykh kogn itivnykh preim ushchestv ot dobavok u zdorovykh pozhilykh lyudey. Polza dlya kozhi luchshe podtverzhdena issledovaniyami topicheskogo vitamina E, ne zhe li dan nymi po peroral nym dobavkam.
Luchshe li natural ny vitamin E, chem sinteticheskiy?
Natural ny d-alfa-tokoferol zaderzh ivayetsya v tkanyakh primerno vdvoe luchshe, che m sinteticheskiy dl-alfa-tokoferol (Traber, 2006). Dlya pozhilykh s ogranichennm potrebleniem zhira dobavki s vitaminomy E iz prirodnykh istochnikov obespechi vayut luchshuyu dostavku v tkani na milligramm.
Mozhno li prinimat vitamin E ezhednevno dlongo vremenno?
V nizkikh i umerennykh dozakh (do okolo 200 ME v den) ezhednevny dlitelly priom kazhetsya bezopasnym dlya zdorovykh vzroslykh bez ispolzovaniya antikoagulyantov. Bolee vysokie dozy v techenie dlitelnogo perioda sleduyet kontrolirovat, osobenno u pozhilykh s serdechno-sosudi stymi zabolevaniyami.
Literatura
Traber, M. G. (2006). Vitamin E regulatory mechanisms. Annual Review of Nutrition, 27, 347-362.
Miller, E. R., Pastor-Barriuso, R., Dalal, D., Riemersma, R. A., Appel, L. J., & Guallar, E. (2005). Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Annals of Internal Medicine, 142(1), 37-46.
Bjelakovic, G., Nikolova, D., Gluud, L. L., Simonetti, R. G., & Gluud, C. (2012). Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database of Systematic Reviews, (3), CD007176.
