People consuming PUFA are less likely to
suffer from cardiovascular disease. As humans are not able to synthesize
omega 3 polyunsaturated fatty acid (PUFA), they must be supplied to the
body in the diet. These fatty acids accomplish the synthesis of other
essential fats.
One important fatty acid is Dechexanoic Acid (DHA), present in high
concentration in retina, cerebral cortex, testis and sperm. It is
particularly needed for the development of the brain and the retina.
The outer segment of retinal rods contains very high concentration of
DHA which plays an important role in high fluidity necessary for
functioning of Rhodopsin (a protein in external segments of the rods of
the retina).
Thus, it plays an important role in functioning of the eye. Similarly
they are essential to keep your heart healthy as they tend to raise your
HDL level and decrease your LDL level. HDL is called good cholesterol
and LDL bad cholesterol. It is found that people having less HDL
cholesterol are more prone to heart disease or they may have
contradicted their first heart attack.
All these fatty acids are present in fish; thus, fish is a good source
of essential fat in a diet. Also these PUFA inhibit aggregate of
platelets thus, inhibiting formation of blood clot.
However, on another study the opposite was found; increased fish
consumption = increased cardiovascular diseases. This result was based
on a specific study on fresh water fish from the Finnish Lake where
mercury content was high.
Fish is the primary source of mercury exposure in humans. Mercury is a
toxic metal that can exist as pure element or in a variety of organic
and inorganic forms. Mercury is harmful in all its forms. It can cause
immunosensory, neurological motor and behavioral dysfunction.
Mercury increases the production of super-oxide anion which can damage
heart cells by causing lipid per-oxidation. Super-oxide anion can even
break DNA strand and can lead to a complete damage of heart cells.
Though it is a medical fact that fish are good for a healthy heart, fish
source and the amount consumed is very important otherwise this
preventive treatment may act as a poison.
Methyl mercury is another form of poisoning mercury. It is almost
completely absorbed from the digestive tract and easily accumulated in
the brain and damaging its tissues. It is also seen that methyl mercury
poisoning cause damages to specific areas of the brain, such as visual
cortex or granule layer of cerebrum.
Methyl mercury poisoning symptoms include visual and hearing
abnormalities, muscle weakness, tumor and mental deterioration. The
fetal brain is much more sensitive for low doses of methyl mercury than
adult. Therefore, pregnant women should be more cautious about their
fish intake, they must be careful for the source of fish.
The guidelines about good fish source can be collected from the local
environmental and health authorities.
Once higher level of mercury is detected in the water, the state post
fish advisories must warn consumers to limit their intake.
However, according to Science Journal [278: 1904 – 1905 (1997)], 7
ounces of fish per week is considered to be good and healthy for a woman
of 60kg.
Overall fish is an important part of a balanced diet; it is full of
vitamins, and other nutrients, including essential fatty acids. It helps
in lowering cholesterol level and in controlling blood pressure.
It is therefore important that you do not cut fish from your menu but be
little cautious about the source and the amount of intake.
This story
was posted on AME Info by Dr. Raouf Roshdi, Managing Director, WAW
Health
Sunday, August 31 - 2003
Source:
www.ameinfo.com
Public Health