Omega
3
What is the relationship between omega-3 and cancer?
Cancer is less common in communities that eat large amounts of fish,
and the reason is thought to be the presence in fish of the long
chain omega-3 polyunsaturates. Japanese women, for example, eat
a lot of fish, and have a very low rate of breast, (and other) cancer.
Men who eat fish frequently have a lower risk of prostate cancer.
Stomach and intestinal cancers also appear to be less common in
fish eaters. It is difficult to be specific about this though, because
in such studies, there are often several factors that are different,
and which could explain the lower cancer incidence. Laboratory studies
have provided more support to the idea that the omega-3 polyunsaturates
can reduce cancer risk. For example, tests have shown that cancer-treating
drugs work more effectively when there is a good level of omega-3
polyunsaturates in the diet. Other studies have shown that adding
omega-3s to the diet helps to reduce the level of certain hormone-like
substances, which tend to be present in higher amounts in cancer
sufferers. In summary, it can be said that while there are good
grounds for believing that adding omega-3 polyunsaturates to the
diet will help to reduce cancer risk, it is not yet proven beyond
doubt.
I have heard of the benefits of omega-3 for the developing
fetus. Any info on safety or recommendation of fish oil capsules.
Should expecting Mother’s take Omega 3?
The long chain omega-3 polyunsaturates are essential for the optimal
development of the fetus. They are especially important for the
formation of a healthy brain, eyes and nervous system. Each is made
up in large part from the long chain omega-3s and studies have shown
that if the mother's diet does not provide sufficient omega-3, then
the formation and function of the fetal organs can be impaired somewhat.
Salmon, like other oil-rich fish, is an excellent source of the
long chain omega-3 polyunsaturates. Approximately 20% of salmon
oil is made up of the omega-3 polyunsaturates, of which the two
major components are EPA and DHA. There is no information which
suggests that salmon oil capsules are not safe. As far as intake
recommendation is concerned, for the average pregnant woman, experts
recommend an intake of 650mg of long chain omega-3 polyunsaturates
per day, of which at least 300mg should be DHA. Thus to achieve
this intake from Fish oil capsules, a daily intake of 3000mg of
oil will be needed.
How does omega-3 aid in weight watching?
The long chain omega-3 polyunsaturates can aid weight loss by enabling
each of the body's cells to function in the optimal manner. Accumulation
of fat is the body's response to a surplus of energy over needs.
When the reverse occurs, as in a weight loss diet, the stored energy
(fat) should be liberated and burned. However, some people appear
to have a problem with this mechanism, and it has been suggested
that a part of the reason for this is that the membranes which surround
each of the body's cells are not functioning in the way they should
because their composition is out of balance. Cell membranes are
made up largely of polyunsaturates. We now know that there are two
families of polyunsaturates which are important in the make up of
cell membranes: the omega-3 family from fish, and the omega-6 family
from vegetable oils like sunflower seed oil. Over the past 50 years,
diets in the West have changed, to supply about twice as much omega-6,
and only half as much omega-3. Thus the balance has changed. Cell
membrane composition has changed too, and some scientists think
that this change in membrane composition has made it more difficult
for cells to lose the accumulated fat they contain. Evidence recently
published showed that weight loss was greater on a calorie-restricted
diet when a small amount of fish oil was added to the diet, compared
to the same diet when olive oil was added instead of the fish oil.
What are the benefits of EPA? I use this supplement for
everyday and one tablet per day.
EPA, or eicosapentaenoic acid, is one of the long chain omega-3
polyunsaturates found mainly in the oil from fish. Having a small
amount of EPA and its related polyunsaturate DHA, or docosahexaenoic
acid, (e.g. 650mg/day) is reckoned by those scientists studying
this subject to be a sensible dietary goal. This amount will provide
some protection from heart disease, and perhaps cancer, depression
and other common ills.
Could you give more info on products enriched with omega-3 - e.g.
bread, spread, milk, juices
The availability of ordinary foods fortified with small amounts
of fish oils varies from one country to another, but in general
is increasing all the time, as awareness of the health benefits
of the long chain omega-3 polyunsaturates spreads. In the Asian/Pacific
region, there are milks, yoghurts, and fruit juices available containing
the omega-3s. In the U.S. and Europe there are eggs, spreads, and
juices available. In Scandinavia and Australia there are breads
and eggs available. In Britain at present there are only eggs with
an enhanced omega-3 level.
Could you please expand on omega-3 and psoriasis:
The relationship between psoriasis and the long chain polyunsaturates
from fish oil is one which is quite well documented scientifically.
Psoriasis is one of the inflammatory diseases and increasing the
amount of the long chain omega-3 polyunsaturates in the diet is
known to aid in bringing about a more anti-inflammatory state. The
first trials in this area were carried out in the early 1980s and
they showed that taking 10g of fish oil daily for 3 months brought
about a lessening of psoriatic symptoms such as itching, flakiness
and redness of skin, as well as a reduction in the amount of the
body affected. Since the, several other trials have been carried
out - all showing much the same thing. The disease is not cured
by the omega-3 polyunsaturates, but it does become much easier to
live with, and can be more readily controlled. Another aspect of
the situation is that the omega-3 polyunsaturates can help to counteract
some of the adverse effects of conventional psoriasis drugs.
What are the neurological health benefits of omega-3?
A significant part of the structure of brain, nerves and the retina
of the eye is composed of the long chain omega-3 polyunsaturates
such as are only found in fish oil. The long chain omega-3 polyunsaturates
are essential for the optimal development of a healthy brain, eyes
and nervous system. Studies have shown that if the diet does not
provide sufficient omega-3, then the formation and function of these
vital organs is impaired somewhat. Depression or bipolar disorder
is one common condition thought to be affected by brain omega-3
levels. Studies comparing the incidence of depression in different
areas of the world have suggested that depression is less common
in areas where large amounts of fish are consumed. Studies from
hospitals have also recently provided another type of evidence that
depression might well be linked with a shortage of the long chain
omega-3 polyunsaturates from fish. Research published in the Archives
of General Psychiatry (199; 56:407-412) reported the results of
a study in which severe manic-depressives (bipolar disorder) patients
were treated with long chain omega-3 polyunsaturates (10g/day) from
fish oil. A control group was given olive oil instead of fish oil.
After 4 months, the trial was stopped because the fish oil group
had improved so much that it would have been unethical to continue
to deny the benefits to the placebo group. Other areas in which
the long chain omega-3 polyunsaturates from fish are thought to
be involved include eyesight development in very young children,
dyslexia, dyspraxia, hyperactivity, intelligence, problem solving
ability, and even protection from mental illnesses such as schizophrenia.
Research on all these areas is not yet well developed, but the indications
are substantial, and consistent with epidemiological observations,
and the theoretical predictions of experts in these areas.
How much omega-3 can be obtained from fresh water lake fish,
if any?
Freshwater fish can be a useful source of the long chain omega-3
polyunsaturates, but the amount is very variable, depending on conditions.
The amount depends on the type of plankton and microscopic plants
found in the water in which the fish are reared. Tropical areas
often have different organisms to those found in more temperate
areas and, as a result, can have low omega-3 levels. If the fish
are farmed, the type of food they are fed will have a big influence.
For more information relevant to your area, try asking local universities
if they have more detailed information. Also ask of the mercury
and lead counts.
Are sardines a good source of omega-3? Does the canning
process affect content?
Sardines are generally a good source of omega-3s. The canning process
does not adversely affect levels. The processing is carried out
under oxygen-free conditions and so no significant damaged occurs.
Similarly with the oil in capsules - as long as oxygen is kept away,
damage is negligible
Is there a high, or even not so high, concentration of omega-3
in regular tuna? I've heard albacore tuna has a lot. I eat tuna
sandwiches every day, but I'm not sure that they're albacore tuna.
Does it make a difference?
Fresh and frozen tuna are excellent sources of long chain omega-3
polyunsaturates, supplying around 5% total oil of which 20% is omega-3.
However, during the canning process, most of the oil and therefore
most of the omega-3 is lost. This is mainly because tuna is cooked
before it is canned, and during the cooking process much of the
oil is separated and lost. The meat that goes in the tin thus has
a low oil content (usually less than 1g per 100g) and a low omega-3
content (usually less than 0.4g per 100g). It matters little whether
the tuna is albacore or yellow fin because once it is canned there
is little omega-3 left. Some tuna packers do can raw tuna so that
the omega-3 content is higher, but it is usually difficult to distinguish
such products from the others in the marketplace. Enquire of the
producer to be certain. These comments only apply to tuna. Other
canned fish are just as good as the raw fish as sources of long
chain omega-3 polyunsaturates.
I would like to know if it's OK for children to take omega-3
and how much?
Omega-3 is perfectly safe for children to take, though practical
problems can make it difficult for children under 5. As far as amounts
are concerned, for children between 5 and 10 years of age, I suggest
you try to get an intake of around 300mg per day of long chain omega-3
(from fish oil). If you want to use vegetable omega-3, you must
increase this by 10 times to have the same effect. For children
over 10, we suggest about 500mg per day.
Have there been studies showing the relationship between
omega-3 and such conditions as Tourette syndrome, ADD and OCD?
To date there have been no published studies looking at the relationship
between omega-3 intake and Tourette's syndrome or OCD. Some studies
have been reported on ADD (ADHD) but so far these are only observational
studies which suggest that ADHD sufferers have low omega-3 levels.
There are currently two studies underway in which patients with
ADHD are being given omega-3 supplements, but so far the results
have not been published, though they are due sometime in 2000.
I am interested in starting to take omega-3 and was wondering
whether there are any drug or vitamin interactions. Also, do I have
to take the fish oil with a vitamin E supplement?
The omega-3 polyunsaturates are components of foods and as such
will not likely to interact with drugs, though it is difficult to
be exact since there are so many drugs being launched all the time.
If you are taking any drug on the recommendation of a physician
it would be wise to inform him or her when next you visit. There
are no known interactions with vitamins or minerals. It is a good
idea to ensure a good intake of vitamin E if you are going to take
an omega-3 supplement.
Does
Omega 3 oil actually oil the joints - and if so, how does it get
there?
It has been known for quite some time that the reason Omega 3 oil
relieves joint pain and helps maintain joint suppleness and flexibility
is that it contains omega-3 long-chain polyunsaturates - the most
powerful anti-inflammatory found in nature. The omega-3 are delivered
to the site of the inflammation in the blood.
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