FISH AND HUMAN NUTRITION

FISH AND HUMAN NUTRITION

INTRODUCTION

Fish  makes  a  vital  contribution  to  the  survival  and  health  of  a  significant  portion  of  the  world’s
population.  Fish  is  especially  important  in  the  developing  world.  In  some  of  Asia’s  poorest  countries
(Bangladesh,  Cambodia)  people  derive  as  much  as  75%  of  their  daily  protein  from  fish.  In  West  Africa
fish accounts for 30% of animal protein intake, and this number would be larger if the poor could afford
to buy more. 
Often referred to as “rich food for poor people,” fish provides essential nourishment, especially quality
proteins and fats (macronutrients), vitamins and minerals (micronutrients). Second, for those involved in
fisheries,  aquaculture  and  fish  trade,  fish  is  a  source  of  income  which  can  be  used  to  purchase  other
additional food items. Though this brief emphasizes the former, fish contributes to food security as an
important  accompaniment  to  rice‐based  diets  in  Asia  and  maize‐  and  cassava‐based  diets  in  Africa,
though  its  consumption  there  is  decreasing.  Fish  supply  in  Africa  has  been  declining  for  a  number  of
reasons while the demand has increased due to the rise in population. Strategies to increase fish supply
are being promoted globally.
Malnutrition  is  still  a  problem  in  many  countries  particularly  in  Africa.  It  is  estimated  that  47  million
children under five years old are stunted in sub‐Saharan Africa whereas in eastern and southern Africa
the figure stands at 24 million. Micronutrient deficiencies of vitamin A, iron and iodine are also of public
health  concern  in  the  whole  African  region.  Their  consequences  include  nutritional  blindness,  poor
learning  capabilities,  poor  growth  and  increased  morbidity  and  mortality  rates.  Development  and
agricultural programmes including fisheries and aquaculture which mainstream nutrition issues can go a
long way in alleviating the problem of malnutrition in this part of the world as well as in other countries.

FISH AND MACRONUTRIENTS
Proteins
Proteins are important for growth and development of the body, maintenance and repairing of worn out
tissues  and  for  production  of  enzymes  and  hormones  required  for  many  body  processes.  The
importance of fish in providing easily digested protein of high biological value is well documented. In the
past  this  has  served  as  a  justification  for  promoting  fisheries  and  aquaculture  activities  in  several
countries. On a fresh‐weight basis, fish contains a good quantity of protein, about 18‐20%, and contains
all the eight essential amino acids including the sulphur‐containing lysine, methionine, and cysteine. As
most maize‐based diets lack these compounds, rural households in Africa dependent on maize greatly
benefit  by  increasing  their  fish  consumption.  Fish  also  complements  cassava‐based  diets  which  are
generally low in protein.
Fats
The fat content of fish varies depending on the species as well as the season but, in general, fish have
less fat than red meats. The fat content ranges from 0.2% to 25%. However, fats from fatty fish species
contain  the  polyunsaturated  fatty  acids  (PUFAs)  namely  EPA  (eicosapentaenoic  acid)  and  DHA
(docosahexaenoic acid) (omega 3 fatty acids) which are essential for proper growth of children and are
not  associated  with  the  occurrence  of  cardiovascular  diseases  such  as  coronary  heart  disease.  In
pregnant  women,  the  presence  of  PUFAs  in  their  diets  has  been  associated  with  proper  brain
development  among  unborn  babies.  In  other  studies,  omega  3  fatty  acids  have  also  been  associated
with reduced risk of preterm delivery and low birth weight. The fat also contributes to energy supplies
and assists in the proper absorption of fat soluble vitamins namely A, D, E, and K.
 
FISH AND MICRONUTRIENTS
Vitamins
Fish  is  a  rich  source  of  vitamins,  particularly  vitamins  A  and  D  from  fatty  species,  as  well  as  thiamin,
riboflavin and niacin (vitamins B1, B2 and B3). Vitamin A from fish is more readily available to the body
than from plant foods. Vitamin A is required for normal vision and for bone growth. Fatty fish contains
more vitamin A than lean species. Studies have shown that mortality is reduced for children under five
with a good vitamin A status. As sun drying destroys most of the available vitamin A better processing
methods are required to preserve this vitamin.
Vitamin D present in fish liver and oils is crucial for bone growth since it is essential for the absorption
and metabolism of calcium. Thiamin, niacin and riboflavin are important for energy metabolism. If eaten
fresh, fish also contains a little vitamin C which is important for proper healing of wounds, normal health
of body tissues and aids in the absorption of iron in the human body.

Minerals
The minerals present in fish include iron, calcium, zinc, iodine (from marine fish), phosphorus, selenium
and fluorine. These minerals are highly ‘bioavailable’ meaning that they are easily absorbed by the body.
Iron is important in the synthesis of hemoglobin in red blood cells which is important for transporting
oxygen to all parts of the body. Iron deficiency is associated with anemia, impaired brain function and in
infants is associated with poor learning ability and poor behavior. Due to its role in the immune system,
its deficiency may also be associated with increased risk of infection.
Calcium is required for strong bones (formation and mineralization) and for the normal functioning of
muscles and the nervous system. It is also important in the blood clotting process. Vitamin D is required
for its proper absorption. The intake of calcium, phosphorus and fluorine is higher when small fish are
eaten  with  their  bones  rather  than  when  the  fish  bones  are  discarded.  Deficiency  of  calcium  may  be
associated  with  rickets  in  young  children  and  osteomalacia  (softening  of  bones)  in  adults  and  older
people. Fluorine is also important for strong bones and teeth.
Zinc  is  required  for  most  body  processes  as  it  occurs  together  with  proteins  in  essential  enzymes
required for metabolism. Zinc plays an important role in growth and development as well in the proper
functioning of the immune system and for a healthy skin. Zinc deficiency is associated with poor growth,
skin problems and loss of hair among other problems.
Iodine, present in seafood, is important for hormones that regulate body metabolism and in children it is
required  for  growth  and  normal  mental  development.  A  deficiency  of  iodine  may  lead  to  goiter
(enlarged thyroid gland) and mental retardation in children.
It is evident that fish contribute more to people’s diets than just the high quality protein they are so well
known for. Fish should therefore be an integral component of the diet, preventing malnutrition by
making these macro‐ and micro‐nutrients readily available to the body.

FISH AND FEEDING YOUNG CHILDREN
Fish  is  soft,  easy  to  cook  and  more  easily  digested  than  meat  so  even  young  children  can  be  fed  fish,
contributing  to  improved  nutrient  intake.  Fish  can  also  be  used  as  complementary  foods  especially  in
paste  or  powder  form.  These  products  can  be  used  to  enrich  the  maize‐  and  cassava‐based  porridges
that are normally consumed by young children in rural communities, especially in Africa. However, the
challenge is to develop acceptable fishery products to use as complementary foods for young children as
similar attempts failed in the 1980s and 1990s. Older children can consume fish without any problems
and if well cooked they can benefit tremendously from the small fish that are such an excellent source
of calcium and fluorine—elements crucial for the development of strong bones and teeth in the young.


FISH AND HIV/AIDS
The World Health Authority estimates that people living with HIV survive up to eight years longer if they
have a good, varied diet. Not only is overall health improved, but the efficacy of antiretroviral drugs
appears to be enhanced. Fish can contribute significantly to the nutritional regime of those living with
HIV particularly in terms of the high quality protein and micronutrients that fish provide in a readily
accessible form.
 
THE WAY FORWARD
Realizing  the  importance  of  fish  to  human  nutrition,  in  addition  to  its  role  in  reducing  poverty  and
hunger,  The  WorldFish  Center  will  be  strengthening  its  aquaculture  and  fisheries  programmes  by
mainstreaming nutrition in its community‐based projects. This will ensure a greater impact by improving
the nutritional status of households, particularly those with young children. Research will be undertaken
to gain a better understanding of the role of fish in decreasing malnutrition and improving the health of
the sick. This will also ensure that WorldFish Center programmes contribute to Millennium Development
Goal 4 (reducing child mortality by two thirds by 2015) since high malnutrition levels are associated with
increased child mortality rates.

REPORTED BY,,,,,,,, 
Jasim mubarack pk

MSc Industrial Fisheries