Post on 02-Jun-2018
8/10/2019 Am J Clin Nutr 1976 Lnnerdal 1134 41
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1134
T h e A m e ric an Jo u rn a l o f C lin ica l N u tri tion 2 9: O CT OB ER 1976 , pp . 11 34 -11 41 . P rin ted in U .S .A .
B reas t m ilk com pos itio n in E th iop ian and
S w ed ish m o the rs . II. L ac to se n itro gen and
p ro te in con ten ts13
Bo L {246}nnerdal 4h.D. El isabeih Forsum 5 Ph.D. Mehari Gebre-Medhin 6 M. D. M.P.H.
a nd L eijH ar nb ra eu s 7 M
ABSTRACT B reas t m ilk from underp riv ile ge d a nd p riv ile ged E th io p ia n m othe rs w as co llec ted a t
d iffe ren t s ta ge s o f lac ta t ion a nd ana lyzed fo r to ta l n it rog en , no np ro te in n itroge n , lac tose , a nd
ind iv id ua l m ilk p ro te in s (la c to fe r rin , is -lac ta lbum in , se rum a lbum in , IgG and 1gM ). T he se va lu es
a nd th e m ilk vo lum e o f on e m ea l w ere com pared to co rrespo nd ing re su lts from w e ll-no u r ish ed
Sw ed ish m oth e rs . N o s ign ifica n t d iffe ren ce s b e tw een the le ve ls o f th ese con stituen ts o r the m ilk
v o lum es w ere fo un d be tw een th e tw o g rou ps o f E th io p ia n m oth e rs . W hen com pa ris on wa s m ade be -
tw e en brea s t m ilk from th ese tw o E th io p ia n g ro ups an d th e Sw ed ish g ro up , th e fo rm e r tw o sh ow ed
s ign ific an tly h igh e r v a lu es fo r th e iro n -b in d in g p ro te in lac to fe rrin . Am J C / in N u t r 2 9: 1 13 4-
1141 , 19 76 .
Hum an m ilk is the firs t food a fte r b irth fo r
the m a jo r ity o f ch ild ren . In m any coun tr ie s ,
e spec ia lly the deve lop ing ones , it is the on ly
food up to the age o f 4 to 6 m on ths . B reas t
m ilk is by na tu re ex trao rd ina r ily w e ll adap ted
to the needs o fthe in fan t and its supe rio r ity in
feed ing in fan ts has been und ispu ted th rough -
ou t the yea rs . The es tim a ted requ irem en ts o f
in fan ts fo r p ro te in s (1 ) and m any o the r
nu trien ts a re , the re fo re , based on the com -
pos ition o f b reas t m ilk . B reas t-fed in fan ts a re
le ss liab le to in fe c tions than bo ttle - fed in fan ts
(2 ). In a reas whe re nu tritio na lly adequa te
supp lem en ta ry foods a re sca rce b reas t m ilk is
a va luab le supp lem en t dur ing the second yea r
o f life .
C oncom itan t w ith the in creased ava ilab il-
ity and use o f a rtific ia l fo rm u lae a dec lin ing
trend in the frequency and du ra tion o f b reas t
feed ing has been obse rved in m ost pan ts o f the
w orld in recen t yea rs (3 , 4 ). A lthough nu tri-
tio na lly adequa te fo r the m a in tenance o f
g row th these a rtific ia l subs titu te s la c k som e
o f the un ique fea tu res o f hum an m ilk . B reas t
m ilk , fo r exam p le , con ta in s subs tan tia l
am oun ts o f secre to ry IgA (5 ) and the iron -
b ind ing p ro te in la c to fenn in (6 ) bo th o f wh ich
a re know n to enhance res is tance to in fe c tion .
B reas t m ilk a lso con ta in s com pa ra tiv e ly h igh
le ve ls o f the enzym e ly sozym e (7 ), w h ich is
capab le o f deg rad ing bac te ria l ce ll w a ll, and
re la tiv e ly lange am oun t o f a B 52-b ind ing p ro -
te in tha t has been show n to com pe te w ith
B 12 -rem ov ing m icroo rgan ism s the reby ac ting
bac ten io s ta tica lly (8 ). A no the r un ique fea tu re
is the pa tte rn o f essen tia l am ino ac id s and the
h igh con ten t
o f nonp ro te in n itrogen
( NPN )
(9 ).
It has been p roposed tha t the quan tity and
qua lity o f b rea s t
m ilk a re adve rse ly a ffe c ted
by m a te rna l unde rnu tr itio n bu t h ithe rto con -
duc ted s tud ie s a re in conc lu s ive . G opa lan (10 )
showed tha t the g row th pa tte rn o f b reas t- fed
in fan ts be long ing to unde rnou rished m o thers
w as sa tis fa c to ry , sugges ting adequa te m ilk
p roduc tion . These resu lts have subsequen tly
been con firm ed by o the r au tho rs (Il, 12 ). In
F rom th e In s ti tu te o f N u tr itio n , U n iv e rs ity o f U pp -
s a la Box
551 S -75 1 22 Uppsa la , Sw eden and th e
E th iop ian Nu trit ion Ins titu te , Ad d is Ababa .
2 Th is pa per is a lso lis ted as no . I II in th e se r ies Th e
pro te in co n te n t o f hum an m ilk p ub lis hed by th e Ins ti-
tu te o f N u tr itio n , U ppsa la .
F inanc ia l s upport w as p rov ided by the Swed ish
International Development Authority S IDA) and t he
Swed ish M ed ica l R e sea rch C ounc il (M FR ) (p ro je c t no .
B 7 6- 1 9 X- 47 2 2- Ol .
A ss is ta n t P ro fe sso r o f N u tri tion . A s s is tan t
P ro fes so r o f N utr itio n .
6
D irecto r, E th iop ian Nu tri-
tio n In sti tu te .
Pro fe sso r o f N u tritio n , Institu te o f
Nu trit ion , U ppsa la .
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BREAST MI LK COMPOSI TI ON
1 1 3 5
c on tras t, som e inv estiga to rs have show n re -
duc ed lacta tion pe rfo rm anc e in m a lnou rished
w om en (13 , 14 ). O f spec ia l in te rest a re the
obse rva tions m ade by D eb and C am a (15 )
and o f L indb lad
and
R ah im too la (16 ), ind i-
c a ting im pa ired p ro te in qua lity in the m ilk
from seve re ly m a lnou rished m o the rs .
The p res ent s tudy describes the p ro te in
c om position o f m ilk from m o the rs be long ing
to tw o d iffe ren t s oc ioec onom ic g roups in
E th iop ia . T he resu lts ob ta ined a re com pa red
to no rm a l da ta , repo rted ea rlie r (17 ), w h ich
a re based on m ilk sam p les c o llec ted from
w e ll-nou ris hed S w ed ish m o the rs .
M aterial
Ethiopia
T h e E th iop ian m o th e rs w e re a ll rec ru ited fro m a
c om pre he ns iv e s tu dy o f th e nu tri tion a l as p ec ts o f p re g -
na nc y an d lac ta tion d irec ted by E th io p ia n N u tritio n
Ins titu te (E N I). T he y rep re s en t tw o d if fe ren t s o c io ec o -
nom ic g rou ps .
Th e nonprivileged group c om pr is in g 78 m othe rs ,
w as selected from a m unicipal antenatal clinic in the
K irk os a re a o f A dd is A b ab a . A ll the m o the rs w e re
illite ra te a nd h ad a fam ily inc o m e o f le s s than E th $ 10 0
(Eth $1 .00 = U S $ 0 .50 ). T h is g ro up c o ns um es a
m onotonous d ie t w ith a n av e ra ge d ie ta ry p ro te in and
energy intake less than 6 0% o f tha t rec om m e nd ed by
F A O /W H O . O f the p ro te in 97 % is o f p lan t o rig in . In
e ffec t, th is d ie t is in ad equ a te in a ll re s p ec ts e x c e p t fo r
iro n an d th ia m in e (18 ) .
Th e privileged group
compr is ing
26 m oth e rs . w e re
re c ru ite d fro m a n an te na ta l c lin ic fo r p ay ing pa tie n ts in
the D epartm ent of O bstetrics and G ynaecology, A ddis
Ababa U n iv e rs ity ( fo rm e rly H a ile S e la s s ie U n iv e rs ity ) .
B o th the m o the rs a nd the ir s p ou s e s in th is g rou p had
com pleted at least secondary school education and their
fa m ily inc om e w a s g ene ra lly ab ov e E th $ 600 p e r m o n th .
T he d ie ta ry in tak e o f e ne rgy an d n u tr ien ts in th is g rou p
w as a m p le (18 ).
T he s tud y w as c on du c te d d u r ing the p e r iod A p ril to
Septem ber 19 73 . H ea lthy , la c ta tin g m o th e rs w ith ou t
g lu c os u ria o r a lbu m in u r ia , w ith n o rm a l b lo od p res s u re ,
a nd ha v in g no c lin ic a l s y m p to m s o f a c u te o r c h ro n ic
d is e as e w e re s e le c te d c on s e c u tiv e ly fro m b o th c lin ic s .
Further data related to dietary intake, hem atological,
a nd b io ch em ic al c ha ra cte ris tic s
in
th e th ird t r im es te r o f
pregnancy are presented elsew here 18, 19; M . G ebre-
M edhin et al., m a nuscript in preparation .
Sweden
T h e S w ed is h g ro up o f m o the rs w e re a ll he a lth y an d
s oc ioe c o no m ic a lly an d ed uc a tio na lly p riv i leg ed . In c om -
m o n w ith p rac tic a lly 1 00 % of c on te m p ora ry S w ed is h
m o thers they all gave birth to the ir b ab ies in a hos p ita l
and stayed in the w ard during S to 7 d ay s a fte r th e
de l i v e r y .
M ethods
M ilk c olle ctio ti
Ethiopia S a m p le s w e re c o lle c te d in the m o rn in g a t a
s pec ia l c lin ic a t
E N I. M o th e rs w e re in s truc ted no t to
b re as t-fe ed the ir c h ild ren a fte r m idn igh t p r io r to m ilk
c o llec tion . T h e m ilk s a m p le s w e re ta k en a fte r ov e rn ig h t
fa s ting ( fo r th e p u rp os e o f b lo od c o lle c tio n ) . B o th b reas ts
w ere em p t ied u s in g an e lec tric p um p (S is te r M a ja s
b re as t p um p ; P u m p E gn e ll A B , T ro l lh# {22 8 } ttan , S w ede n ) , o f
the ty pe u s ed in S w ed en fo r m a ny y e a rs . P um p ing w as
c o n tin ue d un t il m ilk no lon ge r app ea re d in je ts bu t
m ere ly in a tric k le o r d ro p -w is e . A ll s am p le s w ere
c o llec ted by on e p e rs on an d , a fte r re g is tra tion o f v o lum e ,
w ere p la c e d in a de ep free z e a t -20 C w ith in les s tha n I
h r a fte r c o llec tio n . T he s am p le s w e re s u bs e qu en tly
t ran s p o rted in a froz en c o nd itio n to S w ed en by d irec t
fligh t in spec ia l con ta ine rs w ith d ry ic e a nd s to red a t
-7 0 C .
Sweden
M ilk s a m p les fro m th e s e c o nd m e a l o n th e
4 th an d 5 th d ay p os t pa rtu m w e re c o llec ted by a n u rs e
w h ile th e m o th e r w as s t ill in the m a te rn ity w a rd . M o the rs
w ho s e c h ild ren w e re 3 w ee k s o ld o r o lde r w e re v is ited in
the ir ho m e s by a n u rs e . T he d ay be fo re the s a m p le s w ere
c o llec ted , the m o th e r w as ins tru c te d on h ow to w e igh th e
c h ild be fo re an d a fte r e ac h fe ed ing th rou gh ou t 24 h r
s ta rtin g ea rly in th e m orn ing . O n the s a m p lin g da y . th e
n u rs e v is ited the m o the r a t the s ec on d m ea l o f the da y
w he n th e in fan t w a s a llo w e d to nu rs e on o ne b rea s t w h ile
the o the r w as e m p tie d b y pu m p ing . A fte r m ix in g , a 20 -m I
a liqu o t w as tak en fo r an a ly s is an d th e res t o f th e m ilk
wa s
o ffe re d to th e c h ild . In s om e in s ta nc es s a m p le s w ere
k ep t in a n o rd in a ry re frig e ra to r fo r up to I w e ek b e fo re
b e in g p lac e d in a d eep free z e a t -7 0 C .
F u rthe r de ta ils reg a rd ing th e c lin ic a l m a te r ia l an d
s am p ling p roc edu re s in bo th th e E th io p ia n a nd S w e d is h
groups a re found in
the firs t o f the s e s e rie s o f inv e s tiga -
t ion s (2 0) .
A na lvtica l proce dure s
M etho ds fo r es t im a tio n o f to ta l n itrog en , N P N , lac -
to fe rrin , s e rum a lb um in , a - lac ta lbu m in , lg G , 1g M , an d
lac tose a re g iven in a com pa n ion pa per. In fo rm a tion
re ga rd ing th e s ta tis tic a l ev a lu a tio n c a n a ls o b e fo un d in
th is pa pe r (1 7 ).
R esults
The n itrogen d is tr ibu tion , lac tose c oncen -
tra tion , and m ilk vo lum e o f the firs t m ea l o f
th e d ay fo r e ac h pe rio d o f lac ta t ion fo r
E th iop ian and S w ed ish m o the rs a re s how n in
T ab le 1
.
The ind iv idua l va lues o f to ta l n itno -
gen and nonp ro te in n itrogen ob ta ined from
the E th iop ian m o the rs a re com pa red w ith the
S w ed ish no rm al m a te ria l in F igu re 1 . The
to ta l n itrogen conc entra tion dec reases rap id ly
du ring the firs t 20 days o f lac ta tion to reach
the leve l o f m a tu re m ilk . A s show n in T ab le I
the n itrogen concen tra tion in one o f the
8/10/2019 Am J Clin Nutr 1976 Lnnerdal 1134 41
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T ot al n it r og en #{149 }non -pnv i teged
p r i v i L e ge d
*non - p r i v i t eged
N on -p ro te in n itro ge n
A
pr i v i Leged
8
2O
1. 0
.. S { 1 4 9 }
.. 8 #{149}
S.
2 I t
.
, I . .
I I 3 6
L ONNE R D L E T L
F IG . I
.
C on c e n tra tio ns o f to ta l n it rog en a nd n on p ro te in n itrog en in m ilk from E th io p ian m o the rs b e lo ng ing to tw o
soc ioeconom ic g roup s com pa red to
m ilk from w e ll-no u r is h ed S w ed is h m o the rs . S o lid lin e in th e m idd le o f striped
area = re g re s s ion l ine fo r th e S w e d is h m a te r ia l. S trip ed a rea = to le ran c e in te rv a l to th e re g re s s ion line .
T B L E I
N itro gen d is trib u t ion , la c to s e c o nc en tra tion , a nd m ilk v o lum e (firs t m e a l o f the d ay )a
M on ths post
p a r t u m
0-0 .5 0 .5 I .5 I .5 3 .5 3 .5 6 .5 6.5
T o ta l n it ro gen
( mg /mI )
E th . n o np ri vi le g ed
Eth .p r i v i l eged
S w e. p riv ile ge d
3 .14
0 .83
3 .0 5 0 .5 9
2 .50 O . l7
2 .89 0 .59
1 .93
0 .24
1 .77
0 .33
1 .97 0 .29
1 .61
0 .21
1 .69
0 .30
1 .48 0 .17
1 .74
0 .30
N PN
( mg /mI )
E th . n o np ri vi le g ed
E th . p ri vi le g ed
S we . p ri vi le ge d
0 .46 0 .06
0 .53
0 .09
0 .43 0 .05
0 .46 0 .08
0 .46
0 .03
0 .36 0 .05
0 .41 0 .05
0 .41
0 .04
0 .34 0 .05
0 .38
0 .07
0 .33 0 .05
Lac tos e
w /v )
E th . n on p ri vi le g ed
E th . p riv ile ge d
Sw e. p riv ileg ed
6 .46
0 .89
5 .93 0 .58
7 .42
0 .51
6 .60
0 .63
7 .02 0 .56
7 .43 0 .48
7 .64
0 .16
7 .33
0 .47
7 .49 0 .31
7 .64
0 .35
7 .78 0 .48
Mi l k v o l u me
m )
Et h . nonpr i v i l e ge d
Et h . p r i v i l e ge d
Swe . p r i v i l e ge d
1 9 7 94
1 5 7 13 1
16 9 91
1 2 4
26
15 3 66
12 6 61
14 5 4 4
18 8 8 8
2 0 6 7 0
1 0 9 72
n
Et h . nonpr i v i l e ge d
Et h . p r i v i l e ge d
S w e. p riv il eg ed
S
15
3
I S
12
1 4
S
12
2 6
11
4 5
2
V a lu es a r e m ea n
S D . S ig n if ic a n tly h ig he r tha n th e c o r res po nd ing v a lue from S w e d is h m o th e rs (0 .0 01
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