Introduction
3
LiPid QuaLity
Lipids of freshwater fish are characterized by high levels of n-3 polyunsaturated fatty acids, e.g., eicosapentaenoic
acid (EPA) and docosahexaenoic acid
(DHA). But they also contain considerable amounts of n-6 fatty acids,
especially linoleic acid and arachidonic acid. While the essential fatty
acid ratio (n-3/n-6) of marine fish
generally varies between 5 and 10, the
essential fatty acid ratio of freshwater
fish is 1 to 4. This seems appropriate
for human nutrition. Because of their
favorable fatty acid composition, the
lipids of freshwater fish are of outstanding nutritional significance. It is
well known that not only the n-6 fatty
acids are essential for human nutrition, but the n-3 fatty acids are just as
necessary and must also be supplied
in the diet. Both series of essential
fatty acids cannot be synthesized by
other animals or humans. Clinical
tests with hypertensive patients in
many countries proved the effectiveness of eating freshwater fish in
lowering blood pressure and plasma
lipids. Hypertensive patients were put
on a 2-week diet of 100 g silver carp
meat (Hypophthalmichthys molitrix)
per day. This resulted in a significant drop in systolic blood pressure
by 15 mmHg and diastolic pressure by 9 mmHg. In blood plasma,
the level of triacylglycerols was
reduced by 0.6 mmol/L, the HDL cholesterol increased by 0.26 mmol/L,
and the phospholipid concentration
remained constant.
MineraL and VitaMin Content
Freshwater fish are also a good source
for several minerals and vitamins in
human nutrition. Their meat is rich
in potassium, phosphorus, sodium,
magnesium, and calcium. The flesh
of freshwater fish also contains some
trace elements, e.g., iron and anganese.
Freshwater fish can also meet the
demand for several vitamins, such as
vitamin A and some B vitamins.
FRESHWATER FISH IN HUMAN NUTRITION
Freshwater fish are a nutritious choice
for lunch or dinner, as they are low
in fat and high in protein. It has been
reported that the average freshwater
fish consumption is 56.6 kg/person/
year, and one serving of most freshwater fish provides more than 30% of the
dietary reference intake of protein for
adults. Freshwater fishes form the major
and often only source of animal protein
for low-income families. Although not
as high in healthy omega-3 fatty acids
as some saltwater fish, one serving of
most fresh water fish provides more
than 30% of the dietary reference intake
of protein for adults.
Freshwater fish are therefore considered to be wholesome foodstuffs of
high nutritive value. As freshwater fish
flesh has good digestibility, it is also
well suited as a healthy diet for children and seniors (Steffens, 2006).
3
LiPid QuaLity
Lipids of freshwater fish are characterized by high levels of n-3 polyunsaturated fatty acids, e.g., eicosapentaenoic
acid (EPA) and docosahexaenoic acid
(DHA). But they also contain considerable amounts of n-6 fatty acids,
especially linoleic acid and arachidonic acid. While the essential fatty
acid ratio (n-3/n-6) of marine fish
generally varies between 5 and 10, the
essential fatty acid ratio of freshwater
fish is 1 to 4. This seems appropriate
for human nutrition. Because of their
favorable fatty acid composition, the
lipids of freshwater fish are of outstanding nutritional significance. It is
well known that not only the n-6 fatty
acids are essential for human nutrition, but the n-3 fatty acids are just as
necessary and must also be supplied
in the diet. Both series of essential
fatty acids cannot be synthesized by
other animals or humans. Clinical
tests with hypertensive patients in
many countries proved the effectiveness of eating freshwater fish in
lowering blood pressure and plasma
lipids. Hypertensive patients were put
on a 2-week diet of 100 g silver carp
meat (Hypophthalmichthys molitrix)
per day. This resulted in a significant drop in systolic blood pressure
by 15 mmHg and diastolic pressure by 9 mmHg. In blood plasma,
the level of triacylglycerols was
reduced by 0.6 mmol/L, the HDL cholesterol increased by 0.26 mmol/L,
and the phospholipid concentration
remained constant.
MineraL and VitaMin Content
Freshwater fish are also a good source
for several minerals and vitamins in
human nutrition. Their meat is rich
in potassium, phosphorus, sodium,
magnesium, and calcium. The flesh
of freshwater fish also contains some
trace elements, e.g., iron and anganese.
Freshwater fish can also meet the
demand for several vitamins, such as
vitamin A and some B vitamins.
FRESHWATER FISH IN HUMAN NUTRITION
Freshwater fish are a nutritious choice
for lunch or dinner, as they are low
in fat and high in protein. It has been
reported that the average freshwater
fish consumption is 56.6 kg/person/
year, and one serving of most freshwater fish provides more than 30% of the
dietary reference intake of protein for
adults. Freshwater fishes form the major
and often only source of animal protein
for low-income families. Although not
as high in healthy omega-3 fatty acids
as some saltwater fish, one serving of
most fresh water fish provides more
than 30% of the dietary reference intake
of protein for adults.
Freshwater fish are therefore considered to be wholesome foodstuffs of
high nutritive value. As freshwater fish
flesh has good digestibility, it is also
well suited as a healthy diet for children and seniors (Steffens, 2006).