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Seafood Nutrition -
Health Benefits of Eating Fish & Seafood
Omega-3 Essential Fatty Acids
Not all fats are bad fats.
The good ones include the fats in the polyunsaturated fatty
acid family, and these are known as 'essential fats', or
more properly 'essential fatty acids'. These "healthy" fats
are vital to health and cannot be made by the human body -
they must be obtained from diet.
Omega-3 essential fats are found almost only in fish and
seafood.
Recognition of the importance of the omega-3s was a major nutritional
break-through that has since generated a great number of international scientific research programmes. Results have clearly shown that not only do they have an essential role in
brain development in the unborn and newborn and are vital to the healthy maintenance and
function of the body - they can also help protect long-term good health and prevent, or
even treat, a number of complaints and diseases.
A study funded by the Federal and NSW State
Government and carried out by the Institute of Respiratory Medicine in Sydney,
Australia, has shown that consumption of oily fish is associated with a reduced
risk of asthma in childhood. The report suggests that an increased consumption
of oily fish may reduce the prevalence of asthma in children. The study found
that the consumption of canned and processed fish was not associated with the
reduced risk of asthma.
| ESSENTIAL |
- Prevention of essential fatty acid deficiency in infancy
- Optimal retinal (eye) and brain development
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| PROTECTIVE |
- Heart disease
- Stroke
- Certain cancers (breast, colon, prostate)
- Asthma
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| THERAPEUTIC |
- Mildly raised blood pressure
- Arthritis
- Autoimmune diseases (lupus, certain kidney disorders)
- Crohn's disease
- Inflammatory skin diseases (eczema, psoriasis)
- Depression, schizophrenia
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Best Fish for Omega 3:
Wild Salmon - Fresh, frozen,
or canned are all OK.
Wild salmon
will cost you
a lot more than the farmed variety, but salmon farming practices produce
waste and can spread parasites and disease to wild fish, among other
problems, according to Seafood Watch
Arctic Char - Farming practices for arctic char aren't linked to
pollution
or contamination, so it's fine to opt for farmed over wild-caught (which
isn't as easy to get anyway). At a sushi bar, you may see it called
iwana.
Atlantic Mackerel - Mackerel populations in general are hardy, so
wild-caught is A-OK. But because the EDF recommends you limit
consumption of the Spanish Mackerel and king varieties of mackerel
because of the potential for mercury contamination, stick to Atlantic
mackerel as a staple.
Sardines - These tiny fish generally come from the Pacific, where
the
population has resurged. Because they're small, they don't come with the
mercury worries of fish higher up the food chain.
Sable Fish or Black Cod - Seafood Watch recommends you
stick to fish caught
off Alaska and British Columbia, where fishing practices have reduced
the
likelihood of the accidental catch of other species.
Anchovies - Exact species isn't important; they're all OK, says
the EDF.
These fish reproduce quickly, so they aren't threatened, and they're
small
enough so that contamination is not an issue.
Oysters - Farming operations produce the vast majority of
oysters.
They are
generally well managed and have a low impact on the environment, so
farmed
oysters are a great choice. At the sushi bar, you may see oysters called
kaki.
Rainbow Trout - Because lake trout in the Great Lakes have been
overfished,
Seafood Watch recommends farmed
rainbow trout,
or golden, trout as the best
choice. Because of moderate PCB contamination, the EDF recommends kids
limit consumption to two to three meals a month, depending on their age.
Albacore Tuna -
Albacore Tuna.
Kids up to age 6 should limit consumption to three meals a month because
of moderate mercury contamination, the EDF says.
Farmed Mussels - Farmed
mussels are
raised in an environmentally responsible manner-in fact, the operations
may actually improve the surrounding marine environment. You may see
them called murugai at a sushi bar
Pacific Halibut - There are lots of different varieties of
halibut, but
Seafood Watch recommends the wild-caught Pacific (also called Alaskan)
variety. Atlantic stocks have declined and are under pressure, and
California halibut is caught using less preferable fishing methods. Kids
should limit consumption to a few meals a month because of potential for
mercury contamination.
Fish that are
high in Omega-3:
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| Atlantic Salmon |
Blue Eye Trevalla |
Blue Mackerel |
| Blue Warehou |
Silver Perch |
Pilchards |
| Rainbow Trout |
Redfish |
Sea Mullet |
| Tailor |
Flathead |
Trevally |
| Threadfin Bream |
Yellowtail Kingfish |
Australian Salmon |
Here is a list of some more fish
high in omega 3 fatty acids.
Albacore tuna
Anchovies
Blue fin tuna
Cod
Halibut
Herring
Hoki
Lake trout
Mackerel - possibly having as much as 2.3g of omega 3
fatty acids for every 100g of fish
Pilchards
Rainbow trout
Sablefish (black cod)
Salmon - possibly having between 1.2g to 1.9g of omega 3
fatty acids for every 100g of fish
Sardines
Sea bass
Swordfish - possibly having 0.6g of omega 3 fatty acids
for every 100g of fish
Tuna
Turbot
Yellow fin tuna
More
information and photos of
fish and seafood
What's an oily fish?
Oily fish are fish that have an oil content greater than 2%.
Fish oil contains the OMEGA-3 fatty acids. Many of the fish with high levels of
OMEGA-3 are reasonably priced and readily available from your local seafood
retailer.
Omega-3 Fatty Acids and Cardiovascular
Health
Fish oil omega-3 fatty acids have been shown to improve
heart health in the following ways:
Reduce the chance of sudden cardiac death. Almost half of
all cardiac deaths in the U.S. - about a quarter of a million
each year - are attributable to sudden cardiac death.
Reduce the chance of having a first heart attack. People
at high risk of having a heart attack may reduce their chance of
a first myocardial infarction (heart attack) by consuming fish
oil omega-3s regularly.
Reduce the risk of stroke. Several studies have shown
that people who consume fish regularly are less likely to have a
stroke.
Lower blood triglycerides (fats). Many people, especially
those with type 2 or non-insulin dependent diabetes mellitus,
have high triglycerides, which significantly increases the risk
of heart disease. Regular consumption of fish oil omega-3s
lowers blood triglyceride levels, especially in people whose
triglycerides are above normal levels.
May increase high-density lipoprotein levels, the so-called
"good" cholesterol that reduces the risk of heart disease.
This favorable change often occurs in people with high
triglycerides or type 2 diabetes, where the risk of heart
disease is increased three times or more.
Reduce the likelihood of blood clots forming in arteries.
Blood clots can be fatal. Fish oil omega-3 fatty acids make
platelet clumping less likely and reduce the activity or
production of several substances that promote clot formation.
They may encourage the production of substances that promote the
breakdown of clots, as well.
Improve vascular function. The cells lining the blood
vessels are called endothelial cells. They produce substances
that maintain blood fluidity and vessel wall muscle tone. Fish
oil omega-3 fatty acids inhibit excessive endothelial cell
activity that could lead to a heart attack. Omega-3s encourage
blood vessel wall relaxation, which improves blood flow and
reduces pressure.
Reduce inflammation. Fish oil omega-3 fatty acids
discourage the development of inflammation in blood vessels that
frequently accompanies heart disease. Inflammatory conditions
stimulate the production of substances involved in clot
formation and make artery disease worse. Inflammation increases
the risk of heart failure.
May stabilize atherosclerotic plaques. Recent findings
suggest that fish oil omega-3s may increase the stability of
atherosclerotic plaques making them less likely to rupture and
cause a heart attack.
Modestly reduce blood pressure. High blood pressure
greatly increases the risk of heart disease and stroke.
Consuming fish oil omega-3s is associated with small but
beneficial reductions in blood pressure.
Maternal and Infant Health
Fish oil omega-3 fatty acids are essential for healthy fetal and
infant development. During pregnancy, the developing baby
obtains omega-3 fatty acids from the mother. After birth, the
infant must obtain them from breast milk or formula supplemented
with essential fatty acids. In early human development, fish oil
omega-3 fatty acids are beneficial for:
Healthy infant visual function. The photoreceptor cells
in the retina of the eye have large amounts of DHA, which is
involved in visual function. Infants whose diets contain fish
oil omega-3 fatty acids have improved visual scores on a number
of measures of visual acuity when compared with infants not
receiving them.
Improved infant neurodevelopment. Several tests of motor
skills, learning behavior, language development, and mental
function in infants and children have shown that infants
consuming fish oil omega-3 fatty acids from breast milk or
supplemented formula have higher developmental measures than
those not receiving them. In several studies, infants consuming
omega-3s exhibited a more mature type of neurodevelopment than
those of the same age who did not have omega-3 fatty acids. It
is not certain whether the findings in infancy carry over into
childhood and adulthood.
Reduced risk of premature and underweight births.
Consuming omega-3s - particularly DHA* - in pregnancy,
especially in the last trimester, reduces the risk of premature
and underweight babies. Studies have shown that babies of
mothers who consumed DHA in the last trimester were heavier than
those of mothers not fed DHA. Gestation time is also prolonged
and this reduces the risk of prematurity.
Important in pregnancy. In the last three months of
pregnancy, the fetus avidly takes up omega-3 fatty acids from
the mother's circulation. These fatty acids are incorporated
into brain, eye, and other tissues. Because the mother's diet
and body stores are the only source of these essential
nutrients, pregnant women are wise to consume fatty fish
regularly.
Important in lactation. In the first six months of life,
infants depend on breast milk or infant formula for all or most
of their nutrition. Nursing women can ensure their infants
receive essential fatty acids by eating fatty fish regularly, at
least once a week. These dietary omega-3s are transferred to
breast milk, so the infant will obtain them.
Low birth weight and premature infants. Underweight and "preemie"
babies are at increased risk of receiving too little omega-3
fatty acids during gestation. When a baby is born early, it has
less time to acquire these vital fatty acids from its mother.
Thus, it is especially important for these infants to receive
all essential fatty acids, including omega-3 fatty acids, to
ensure healthy development. Human milk and fatty acid
supplemented formula will supply the necessary omega-3s.
Improvements in Clinical Conditions*
* Note: always check with your doctor before taking any
substances to alleviate any clinical conditions. These
statements are provided only for information and are not
intended to treat, cure, prevent, or mitigate any existing
health conditions.
Omega-3 fatty acids in fish oils have beneficial effects on
the symptoms of several health conditions that involve the
immune and inflammatory system, intestinal tract, and brain.
They appear to have important benefits in type 2 or non-insulin
dependent diabetes.
Type 2 Diabetes Mellitus
Type 2 diabetes greatly increases the risk of cardiovascular
disease and heart attack. However, diabetics who consume fatty
fish regularly - once or more per week - are less likely to
incur a first heart attack. Mortality from heart disease is also
significantly lower among diabetics who do compared with those
who do not eat fish.
Sugar and fat metabolism are impaired in type 2 diabetes. Blood
triglyceride (fat) levels are increased while high-density
lipoprotein (HDL) levels - the "good cholesterol" - are reduced.
Regular consumption of fatty fish or omega-3 fatty acids
significantly lowers triglycerides and often raises HDL levels,
thereby diminishing the risk of heart disease.
Omega-3s improve blood circulation, reduce the tendency
of blood to clot, improve vascular (blood vessel) function in
several ways that reduce the risk of heart disease, and slightly
lower blood pressure. These changes favor heart health.
Inflammatory Conditions
Omega-3s in fish dampen the production of inflammatory
substances produced in rheumatoid arthritis, psoriasis, asthma,
and some skin conditions. They also stimulate the production of
substances the counteract inflammation. The result is often an
improvement in the symptoms of these conditions, e.g., less
soreness or itching, easier breathing, and less swelling.
Omega-3s may need to be consumed over a long period before
improvements appear.
Crohn's Disease, Ulcerative Colitis
These serious intestinal diseases have strong inflammatory
responses that may become less severe with the regular
consumption of omega-3s from fish. Omega-3s tend to reduce the
severity of the symptoms, but do not cure these conditions.
Mental Function
Emerging evidence suggests that the regular consumption of
omega-3s from fish may be beneficial in reducing the severity of
several mental conditions such as Alzheimer's disease,
depression, and bipolar disorder. In children, improvements with
the consumption of omega-3s have been reported in attention
deficit hyperactivity disorder and dyslexia. Caution is
warranted because data are inconsistent and do not permit firm
conclusions.
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