Rashin ƙarfi na lactase

Dagewar lactase ko haƙurin lactose shine ci gaba da aikin enzyme na lactase a cikin girma, yana ba da damar narkewar lactose a cikin madara . A yawancin dabbobi masu shayarwa, aikin enzyme yana raguwa sosai bayan yaye .  A cikin wasu mutane ko da yake, lactase dagewa ya samo asali ne kwanan nan  a matsayin daidaitawa ga cin abinci maras amfani da madara da kayan kiwo fiye da jariri.  Dagewar lactase yana da yawa a tsakanin mutanen arewacin Turai. A duk duniya, yawancin mutane suna lactase maras jurewa,  kuma suna shafar bambance-bambancen matakan rashin haƙuri na lactose a matsayin manya. Koyaya, dagewar lactase da rashin haƙuri na lactose na iya haɗuwa. [ bayani da ake bukata ]

 Rarraba duniya na phenotype 
Rarraba yanayin lactase (LP) phenotype, ko ikon narkar da lactose zuwa girma, ba daidai ba ne a duniya. Matsakaicin tsayin daka na lactase suna da canji sosai. A cikin Turai, rarrabuwar lactase phenotype ne na asibiti, tare da mitoci daga 15-54% a kudu maso gabas zuwa 89-96% a arewa maso yamma.  Alal misali, kawai 17% na Helenawa da 14% na Sardinians ana annabta su mallaki wannan dabi'a, yayin da kusan 80% -100% na mutane a arewacin Turai da tsakiyar Turai an annabta su zama lactase naci.  Hakazalika, yawan lactase-juya shine asibiti a Indiya, nazarin 2011 na mutane 2,284 da ke nuna yawan LP a cikin al'ummar Ror, na Haryana, a Arewa maso Yamma, na 48.95%, ya ragu zuwa 1.5% a cikin Andamanese, na Kudu maso Gabas, na Arewa maso Gabas, da kuma Timan 0.8.  

 Manazarta