The Importance Of Omega-3 Fatty Acids
The body can?t easily manufacture omega-3?s like Supplements/EPA.html">EPA
and DHA - they are best supplied by our food. Luckily, the one organism
that can make them - plankton - is eaten by certain types of fish
(which are in turn, eaten by other fish). We can eat these fish and so
get the omega-3 the plankton made originally. Alternatively supplements
can be used, which contain the EPA
and DHA found in these oil-rich fish. Fish are generally to be
preferred over supplements, since they supply other important nutrients
like vitamins and minerals also. However, some people are not able or
willing to eat fish, and for them supplements, or fish oil supplemented
foods, are a feasible and sensible way to get omega-3.
If you are a vegetarian, you can get one of the Omega-3 fatty acids
(alpha-linolenic acid or ALA) from sources such as linseed oil or
rapeseed oil, though to be most useful to body, the ALA must first be
converted to EPA and/or DHA. Modern diets make this conversion process
inefficient, so that lots of ALA must be eaten to produce levels of EPA
and DHA comparable to those that can be obtained by eating fish.
Fish and seafoods from cold waters characteristically and uniquely
contain significant quantities of long chain omega-3 polyunsaturates.
Though there is some evidence that fish can elongate and desaturate the
shorter chain omega-3 polyunsaturates, current opinion is that most of
the long chain omega-3 polyunsaturates are formed in the microscopic
algae, plankton and planktonic crustacea at the bottom of the marine
food chain. They are then passed up the food chain into the higher
fish, and of course ultimately to humans.
The fats in fish are low in saturated fatty acids and contain a type
of polyunsaturated fatty acid ('omega'-3) that has been associated with
a decreased risk of heart disease in certain people. Remember that the
total fat in the diet should be consumed at a moderate level - that is,
no more than 30 percent of calories. Mono- and polyunsaturated fat
sources should replace saturated fats within this limit.
Great progress has been made over the past 30 years in identifying
cardiovascular risk factors and in developing and implementing measures
to correct them. The guidelines developed by the Adult Treatment Panel
(ATP) of the National Cholesterol Education Program identified low
density lipoprotein (LDL) as the major atherogenic lipoprotein and high
levels of LDL cholesterol as the primary target for
cholesterol-lowering therapy.
The low incidence of cardiovascular disease in Greenland Eskimos
appears to be due to their high intake of seal, whale and fish. The
lipids of these marine animals lower serum triglyceride and cholesterol
levels and help to prevent blood clotting. The latter effect has been
related to a change in the balance of prostacyclin and thromboxane as a
result of replacing n-6 polyunsaturated fatty acids in the body by n-3
polyunsaturated fatty acids present in marine lipids. Dietary fish oils
have also been shown to inhibit development of mammary, pancreatic,
intestinal and prostatic tumors in experimental animals. This effect
may likewise be due to changes in the production of prostaglandins or
related compounds. The involvement of prostaglandins and leukotrienes
in immune responses has led to studies on the effects of fish oil on
various chronic diseases associated with abnormalities of the immune
system. Some of these diseases, such as multiple sclerosis and
psoriasis, are also relatively uncommon in Eskimos. Preliminary results
of these studies are encouraging, but more work is required to assess
the usefulness of dietary fish oils in treatment of these diseases. In
addition to their apparent therapeutic value, n-3 fatty acids are
considered essential dietary components since they cannot be
synthesized in the body and appear necessary for normal vision and
probably other body functions.
From population studies, diets high in fish are associated with
reduced CHD risk. Fish oils and omega-3 fatty acids result in decreased
triglycerides, and may increase LDL-Cholesterol and/or apolipoprotein B
level(s). They also impair clotting and diabetic control. Omega-3 fatty
acids, in large amounts, may reduce excessive triglyceride levels that
do not respond adequately to recommended dietary therapy.
Published clinical research, as well as various theoretical
considerations, suggest that supplemental intakes of the 'metavitamins'
taurine, coenzyme Q10, and L-carnitine, as well as of the minerals
magnesium, potassium, and chromium, may be of therapeutic benefit in
congestive heart failure. High intakes of fish oil may likewise be
beneficial in this syndrome. Fish oil may decrease cardiac afterload by
an antivasopressor action and by reducing blood viscosity, may reduce
arrhythmic risk despite supporting the heart's beta-adrenergic
responsiveness, may decrease fibrotic cardiac remodeling by impeding
the action of angiotensin II and, in patients with coronary disease,
may reduce the risk of atherothrombotic ischemic complications. Since
the measures recommended here are nutritional and carry little if any
toxic risk, there is no reason why their joint application should not
be studied as a comprehensive nutritional therapy for congestive heart
failure.
Other studies have indicated that omega-3 fatty acids may be effective in treating mood disorders.
For example, one investigator has shown a correlation between the
prevalence of major depression and the amount of fish consumed per
capita worldwide. Others have found decreased amounts of EPA
(one of the active ingredients in omega-3 fatty acids) in the red blood
cells of patients with major depression. And a recent small study of
patients with bipolar illness indicated that omega-3 fatty acids
prevented relapses, especially of depression, in patients.
This journal article describes a study of the potential
mood-stabilizing properties of omega 3 fatty acids in bipolar
(manic-depressive) disorder. Thirty patients with bipolar disorder,
aged 18 to 65 years, participated in this placebo-controlled,
double-blind trial. The patients were randomly assigned to receive
omega 3 fatty acids (9.6 g/d) or placebo (olive oil), in addition to
their regular treatment, for 4 months. Randomization was stratified
according to sex, the presence or absence of concurrent lithium
treatment, and the presence or absence of rapid cycling. A Kaplan-Meier
survival analysis showed that the omega 3 fatty acid group had a
significantly longer period of remission than the placebo group. The
omega 3 fatty acid group also performed better than the placebo group
on nearly every other outcome measure. Treatment was generally well
tolerated. The authors conclude that the addition of omega 3 fatty
acids appears to have improved the short-term course of illness in this
group of patients with bipolar disorder.
The old wives adage that fish is brain food received a substantial
boost when the results of a research project were announced. The study
looked at the possible value of fish oil in the treatment of
hospitalised manic-depressives. These patients are severely affected,
and suffer violent mood swings which range from suicidal depression, to
raging mania. 30 such patients were involved in the trial, half given
fish oil, and half a placebo. Fish oil has in the previous studies
shown suggestions that it might be useful in the treatment of mental
disorders. The double blind study, carried out by Dr Andrew Stoll and
colleagues at the McLean Hospital in Belmont, Massachusetts, was
planned to last 4 months, but was brought to a premature conclusion,
because the benefits of the fish oil treatment were so marked, that it
was considered unethical to continue to deny the same benefits to the
patients taking the placebo treatment. The study was published in the
May 1999 issue of the journal Archives of General Psychiatry. Severe
bipolar disorder, as the condition is known medically, affects around
1% of the population, and around 10-15% of those affected die from
suicide. The prevalence of the condition has increased 100 fold in the
past 100 years, but the condition is rare in fish-eating countries such
as Japan, Korea, Malaysia and Taiwan. Current drug therapy is not well
accepted by patients in contrast to the fish oil treatment used in this
study.
The value of fish oil in such treatments is thought to be due to
it?s unique content of long chain omega-3 polyunsaturates, and in
particular one called docosahexaenoic acid, or DHA. The brain is unique
in having a high concentration of DHA. It is thought that modern diets
and lifestyles put at risk the body?s ability to maintain brain DHA
level, and that when the level falls, mental problems become more
prevalent. Interestingly, in the 18th century, one treatment
recommended for "melancholia" was to eat cow brain. Like the human
brain and in fact most mammals, cow brain also contains a relatively
high concentration of DHA!
Studies with hospitalised schizophrenics and children suffering from
attention deficit-hyperactivity disorder (ADHD) have also shown that
the long chain omega-3 polyunsaturates in fish oil can have a
beneficial impact on brain function.
The body can?t easily manufacture omega-3?s like Supplements/EPA.html">EPA
and DHA - they are best supplied by our food. Luckily, the one organism
that can make them - plankton - is eaten by certain types of fish
(which are in turn, eaten by other fish). We can eat these fish and so
get the omega-3 the plankton made originally. Alternatively supplements
can be used, which contain the EPA
and DHA found in these oil-rich fish. Fish are generally to be
preferred over supplements, since they supply other important nutrients
like vitamins and minerals also. However, some people are not able or
willing to eat fish, and for them supplements, or fish oil supplemented
foods, are a feasible and sensible way to get omega-3.
If you are a vegetarian, you can get one of the Omega-3 fatty acids
(alpha-linolenic acid or ALA) from sources such as linseed oil or
rapeseed oil, though to be most useful to body, the ALA must first be
converted to EPA and/or DHA. Modern diets make this conversion process
inefficient, so that lots of ALA must be eaten to produce levels of EPA
and DHA comparable to those that can be obtained by eating fish.
Fish and seafoods from cold waters characteristically and uniquely
contain significant quantities of long chain omega-3 polyunsaturates.
Though there is some evidence that fish can elongate and desaturate the
shorter chain omega-3 polyunsaturates, current opinion is that most of
the long chain omega-3 polyunsaturates are formed in the microscopic
algae, plankton and planktonic crustacea at the bottom of the marine
food chain. They are then passed up the food chain into the higher
fish, and of course ultimately to humans.
The fats in fish are low in saturated fatty acids and contain a type
of polyunsaturated fatty acid ('omega'-3) that has been associated with
a decreased risk of heart disease in certain people. Remember that the
total fat in the diet should be consumed at a moderate level - that is,
no more than 30 percent of calories. Mono- and polyunsaturated fat
sources should replace saturated fats within this limit.
Great progress has been made over the past 30 years in identifying
cardiovascular risk factors and in developing and implementing measures
to correct them. The guidelines developed by the Adult Treatment Panel
(ATP) of the National Cholesterol Education Program identified low
density lipoprotein (LDL) as the major atherogenic lipoprotein and high
levels of LDL cholesterol as the primary target for
cholesterol-lowering therapy.
The low incidence of cardiovascular disease in Greenland Eskimos
appears to be due to their high intake of seal, whale and fish. The
lipids of these marine animals lower serum triglyceride and cholesterol
levels and help to prevent blood clotting. The latter effect has been
related to a change in the balance of prostacyclin and thromboxane as a
result of replacing n-6 polyunsaturated fatty acids in the body by n-3
polyunsaturated fatty acids present in marine lipids. Dietary fish oils
have also been shown to inhibit development of mammary, pancreatic,
intestinal and prostatic tumors in experimental animals. This effect
may likewise be due to changes in the production of prostaglandins or
related compounds. The involvement of prostaglandins and leukotrienes
in immune responses has led to studies on the effects of fish oil on
various chronic diseases associated with abnormalities of the immune
system. Some of these diseases, such as multiple sclerosis and
psoriasis, are also relatively uncommon in Eskimos. Preliminary results
of these studies are encouraging, but more work is required to assess
the usefulness of dietary fish oils in treatment of these diseases. In
addition to their apparent therapeutic value, n-3 fatty acids are
considered essential dietary components since they cannot be
synthesized in the body and appear necessary for normal vision and
probably other body functions.
From population studies, diets high in fish are associated with
reduced CHD risk. Fish oils and omega-3 fatty acids result in decreased
triglycerides, and may increase LDL-Cholesterol and/or apolipoprotein B
level(s). They also impair clotting and diabetic control. Omega-3 fatty
acids, in large amounts, may reduce excessive triglyceride levels that
do not respond adequately to recommended dietary therapy.
Published clinical research, as well as various theoretical
considerations, suggest that supplemental intakes of the 'metavitamins'
taurine, coenzyme Q10, and L-carnitine, as well as of the minerals
magnesium, potassium, and chromium, may be of therapeutic benefit in
congestive heart failure. High intakes of fish oil may likewise be
beneficial in this syndrome. Fish oil may decrease cardiac afterload by
an antivasopressor action and by reducing blood viscosity, may reduce
arrhythmic risk despite supporting the heart's beta-adrenergic
responsiveness, may decrease fibrotic cardiac remodeling by impeding
the action of angiotensin II and, in patients with coronary disease,
may reduce the risk of atherothrombotic ischemic complications. Since
the measures recommended here are nutritional and carry little if any
toxic risk, there is no reason why their joint application should not
be studied as a comprehensive nutritional therapy for congestive heart
failure.
Other studies have indicated that omega-3 fatty acids may be effective in treating mood disorders.
For example, one investigator has shown a correlation between the
prevalence of major depression and the amount of fish consumed per
capita worldwide. Others have found decreased amounts of EPA
(one of the active ingredients in omega-3 fatty acids) in the red blood
cells of patients with major depression. And a recent small study of
patients with bipolar illness indicated that omega-3 fatty acids
prevented relapses, especially of depression, in patients.
This journal article describes a study of the potential
mood-stabilizing properties of omega 3 fatty acids in bipolar
(manic-depressive) disorder. Thirty patients with bipolar disorder,
aged 18 to 65 years, participated in this placebo-controlled,
double-blind trial. The patients were randomly assigned to receive
omega 3 fatty acids (9.6 g/d) or placebo (olive oil), in addition to
their regular treatment, for 4 months. Randomization was stratified
according to sex, the presence or absence of concurrent lithium
treatment, and the presence or absence of rapid cycling. A Kaplan-Meier
survival analysis showed that the omega 3 fatty acid group had a
significantly longer period of remission than the placebo group. The
omega 3 fatty acid group also performed better than the placebo group
on nearly every other outcome measure. Treatment was generally well
tolerated. The authors conclude that the addition of omega 3 fatty
acids appears to have improved the short-term course of illness in this
group of patients with bipolar disorder.
The old wives adage that fish is brain food received a substantial
boost when the results of a research project were announced. The study
looked at the possible value of fish oil in the treatment of
hospitalised manic-depressives. These patients are severely affected,
and suffer violent mood swings which range from suicidal depression, to
raging mania. 30 such patients were involved in the trial, half given
fish oil, and half a placebo. Fish oil has in the previous studies
shown suggestions that it might be useful in the treatment of mental
disorders. The double blind study, carried out by Dr Andrew Stoll and
colleagues at the McLean Hospital in Belmont, Massachusetts, was
planned to last 4 months, but was brought to a premature conclusion,
because the benefits of the fish oil treatment were so marked, that it
was considered unethical to continue to deny the same benefits to the
patients taking the placebo treatment. The study was published in the
May 1999 issue of the journal Archives of General Psychiatry. Severe
bipolar disorder, as the condition is known medically, affects around
1% of the population, and around 10-15% of those affected die from
suicide. The prevalence of the condition has increased 100 fold in the
past 100 years, but the condition is rare in fish-eating countries such
as Japan, Korea, Malaysia and Taiwan. Current drug therapy is not well
accepted by patients in contrast to the fish oil treatment used in this
study.
The value of fish oil in such treatments is thought to be due to
it?s unique content of long chain omega-3 polyunsaturates, and in
particular one called docosahexaenoic acid, or DHA. The brain is unique
in having a high concentration of DHA. It is thought that modern diets
and lifestyles put at risk the body?s ability to maintain brain DHA
level, and that when the level falls, mental problems become more
prevalent. Interestingly, in the 18th century, one treatment
recommended for "melancholia" was to eat cow brain. Like the human
brain and in fact most mammals, cow brain also contains a relatively
high concentration of DHA!
Studies with hospitalised schizophrenics and children suffering from
attention deficit-hyperactivity disorder (ADHD) have also shown that
the long chain omega-3 polyunsaturates in fish oil can have a
beneficial impact on brain function.
- The Omega-3 Polyunsaturates. The Fish Foundation. Tiverton,Devon EX16 4QQ, UK.
- Triglyceride, High Density Lipoprotein, and Coronary Heart Disease. NIH Consens Statement 1992 Feb 26-28;10(2):1-28.
- Biological effects of fish oils in relation to chronic diseases. Lipids (UNITED STATES) Dec 1986, 21 (12) p731-2
- Fish oil and other nutritional adjuvants for treatment of
congestive heart failure. Medical Hypotheses (United Kingdom), 1996,
46/4 (400-406) - Stoll, A.L.; et al. Omega 3 Fatty Acids in Bipolar Disorder: A
Preliminary Double-Blind, Placebo-Controlled Trial. Archives of General
Psychiatry. 56: 407-412. May 1999.
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