Study in mice shows that excessive long-term intake of dietary protini containing high amounts of branched-chain amino acids (BCAAs) can result in imbalance in amino acids and appetite control. This affects metabolic health and causes reduced lifespan.
Mwenye afya chakula inapaswa kuwa na kiasi cha usawa cha macronutrients (protini, carbohydrate and fats), fibres, vitamins and minerals. Numerous researches have focused on the importance of balanced amounts of dietary protini, fats and carbohydrates for our good afya. Ukosefu wowote wa usawa katika idadi ya macronutrients haya katika lishe yetu inajulikana kusababisha afya mbaya.
Protini is a complex macromolecule composed of amino acids. There are 20 amino acids, of which nine are essential which can enable the body to make the remaining 11. The branched-chain amino acids (BCAAs) are made up of three of the nine essential amino acids – leucine, isoleucine and valine. Muscles, the main building block of the body are mainly composed of protini. BCAAs are broken down in muscle, have high calories and are consumed for muscle mass they provide. BCAAs are present in protini foods like red meat, eggs, beans, lentils, soy protini etc. and are also commonly present in bodybuilding protini supplements consumed after exercise or workout. Not enough studies have been done to evaluate the adverse effects of consuming excessive BCAAs. Their long-term effects on health and lifespan are still unknown.
Katika utafiti uliochapishwa katika Metabolism ya asili mnamo Aprili 29, 2019 watafiti walilenga kubainisha jinsi kudhibiti BCAA za lishe za muda mrefu kunaweza kuwa na athari kwa afya na maisha. Katika majaribio yao yaliyofanywa kwa panya, wanyama walikula kwa muda wote wa maisha yao ama (a) kiasi cha kawaida cha BCAAs yaani asilimia 200 (b) nusu ya kiasi yaani asilimia 50 au (c) moja ya tano ya kiasi ambacho ni asilimia 20. Kando, panya walipewa isocaloric, kiasi cha kudumu cha macronutrients nyingine - wanga na mafuta. Ulaji wa BCAA nyingi ulisababisha viwango vya juu vya BCAA katika damu na hii ilionekana kuzuia usafirishaji wa tryptophan nyingine isiyo ya BCAA hadi kwenye ubongo. Tryptophan ndio kitangulizi pekee cha homoni ya serotonini ambayo ina athari ya kuinua hali ya hewa na kwa hivyo ni muhimu kwa kukuza usingizi. Mara tu tryptophan ilipozuiwa kufika kwenye ubongo, hii ilisababisha kupungua kwa viwango vya kati vya serotonini na kusababisha ulaji mwingi (au hyperphagia) katika panya hasa kutokana na usawa wa asidi ya amino kupitia kuongezeka kwa uwiano wa BCAAs:non-BCAAs. Kwa hivyo, panya walitumia chakula kupita kiasi (nguvu zote na BCAAs) - pia huitwa ulishaji wa fidia - na kusababisha kuongezeka kwa uzito wa mwili na uzito wa mafuta hivyo kuwafanya wanene na kufupisha maisha yao.
Utafiti huu unaonyesha kuwa uhusiano kati ya kuongezeka kwa viwango vya BCAA zinazozunguka katika damu na matokeo mabaya ya afya haionekani kuhusishwa na sumu ya BCAA au madhara. Uhusiano huo ulitokana na mwingiliano kati ya BCAA na amino asidi nyingine muhimu na hii ndiyo iliyosababisha hyperphagia kali. Matokeo yanapendekeza kwamba kuchukua kiasi kikubwa cha BCAA za chakula kwa muda mrefu pamoja na kiasi kisichobadilika cha macronutrients nyingine inaweza kusababisha hyperphagia inayotokana na usawa wa amino asidi na kuathiri afya ya kimetaboliki na kupunguza muda wa maisha. Ingawa kiasi kikubwa cha BCAA kinaweza kutokea kwa panya wote wenye afya nzuri ya kimetaboliki na wasio na afya. Kwa hiyo, BCAA pekee haiwezi kuwa biomarker pekee kwa afya ya kimetaboliki.
Utafiti wa sasa unathibitisha tena umuhimu wa kula lishe bora yenye uwiano wa aina mbalimbali za virutubisho, nyuzinyuzi, vitamini na madini na kuzuia ulaji wa virutubisho visivyohitajika.
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Chanzo (s)
Solon-Biet SM et al. 2019. Asidi za amino zenye matawi huathiri afya na maisha kwa njia isiyo ya moja kwa moja kupitia usawa wa asidi ya amino na kudhibiti hamu ya kula. Metabolism ya asili. https://doi.org/10.1038/s42255-019-0059-2
