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Essential
Fatty Acids
-EFA's |
Omega-3 Fatty Acids
and Depression by Anthony Kany MD
Introduction
Bipolar disorder and unipolar depression are serious debilitating
psychiatric conditions. Bipolar depression is particularly difficult
to treat, since treatment often pushes the patient into a manic
episode. Bipolar depression carries a 19% suicide rate and bipolar
patients have only a 50% chance of returning to normal functioning.
In the past fifty years there has been about a 20 fold increase in a
number of cases of depressive disorders. 5% of people in the United
States will have at least one episode of serious depression this
year. While most medical research focuses on pharmacological
treatment, there is a growing body of evidence that nutrition in
general, and omega-3 fatty acids in particular may be of great
benefit to numerous people.
Omega-3 Fatty Acids
Omega-3 fatty acids are long-chain, polyunsaturated fatty acids,
which must be obtained through the diet. Long chain omega-3 fatty
acids, like eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)
can be ingested directly from foods such as fish or fish oil.
Alternately they can be manufactured in the liver from alpha
linolenic acid (ALA), a shorter omega-3 fatty acid. This conversion
is limited. Only 5-15% of ALA is ultimately converted. Aging,
illness and stress, as well as high amounts of omega-6 rich oils,
such as corn, safflower, sunflower, or cottonseed oil interfere with
the conversion.
Fish oil contains high levels of the omega-3 fatty acids EPA and DHA.
Flax seed oil contains high amounts of ALA. The dietary intake of
these oils has dramatically declined in Western countries over the
last century. The ideal dietary ratio of omega-6 to omega-3 fats is
approximately 2:1. The ratio of omega-6 to omega-3 fats in the
average American diet is about 20:1.
Given that approximately 20% of the dry weight of the brain is made
up of fatty acids it would not be surprising if inadequate intake of
omega-3 fatty acids would have some neuropsychiatric consequences.
There is a lot of research linking low levels of omega-3 fatty acids
to numerous psychiatric conditions and many indications that omega-3
fatty acids have therapeutic value.
Omega-3 Status in Psychiatric Patients
Numerous studies connect dietary consumption of omega-3 fatty acids
with depression. Countries with high consumption of seafood, high in
omega-3 fatty acids, have lower rates of bipolar and unipolar
depression, post-partum depression, and seasonal affective disorder.
These studies do not prove that low levels of dietary omega-3 fatty
acids cause depression. There are other differences of life style
that may also play a role. However, the evidence is strong enough to
encourage researchers to investigate the role of omega-3 fatty acids
in mental illness.
Studies of the fatty acid status in psychiatric patients have shown
that depressed patients have lower levels of EPA and DHA. This
connection has been demonstrated in mild depression, major
depression, seasonal depression, post-partum depression, and in
suicide.
Possible Mechanisms of Omega-3 Fatty Acids
We
have limited knowledge of how omega-3 fatty acids function in the
brain. There are three major areas in which omega-3 fatty acids seem
to play a role.
Omega-3 fatty acids are essential components in neuronal membranes
and play a critical role in how they function. They allow the nerve
cell to be more receptive to neurotransmitters, enhancing their
effectiveness.
Omega-3 fatty acids also may chemically influence major depression.
Certain chemicals in the brain, called cytokines, which play a role
in the inflammation response, also cause feelings of depression.
Omega-3 fatty acids, and EPA in particular, block the action of
these cytokines. It is worth noting that many antidepressants also
block these inflammatory cytokines.
In addition, there is a chemical in the brain called brain derived
neurotrophic factor. This chemical supports the survival and growth
of neurons. Levels of brain derived neurotrophic factor are low in
patients with severe depression. Omega-3 fatty acids enhance the
function of brain derived neurotrophic factor, as do antidepressant
medication and exercise. Interestingly, diets high in saturated fat
and sugar, as well as stress inhibit its production.
Clinical Evidence
People with depression have lower levels of omega-3 fatty acids. A
number of studies have shown omega-3 fatty acids to be helpful in
treatment of depression.
Several case studies found that flaxseed oil, which is high in alpha
linolenic acid (ALA) the parent compound for all the omega-3 fatty
acids, improved the symptoms of bipolar depression. Another case
showed that a combination of 4 g EPA/2 g DHA per day improved the
depressed symptoms in pregnancy. These improvements took about four
weeks.
In another case study, a patient with depression that didn't respond
to medication was placed on 4 g pure EPA. After one month, the
patient's depression improved and after nine months the patient was
symptom free. Utilizing MRI technology, the researchers found that
after EPA treatment, there were structural changes in the brain that
showed a reversal of some of the brain abnormalities commonly found
in depressed patients.
There was one double blind controlled study that found that 9.6 g of
omega-3 fatty acids (6.2 g EPA/3.4 g DHA) helped bipolar disorder
depression. Another study found that 2 g of pure EPA enhanced the
effectiveness of antidepressant medication. There were no side
effects.
Another study found that 1 g of EPA could reduce aggression and
depression in borderline personality disorder patients, again with
no negative side effects.
The antidepressant effect of omega-3 fatty acids seems to be the
result of EPA. When DHA was given alone or in equal amounts with
EPA, researchers did not see these antidepressant effects.
In summary, omega-3 fatty acids have been tested in numerous
psychiatric conditions and found helpful in:
-
Bipolar
depression
-
Unipolar
depression
-
Depression
during pregnancy
-
Insomnia
-
Anxiety
-
Anorexia
nervosa
-
Depression
associated with borderline personality disorder
-
Post-partum
depression
-
Reduction of
suicidal thoughts
In general, treatment took three to four weeks to be effective,
with the exception of anxiety and insomnia, which took six
weeks. Although doses of up to 9.6 g were used, there were no
significant side effects noted.
Other Dietary Considerations
Certain nutrients are known to influence omega-3 status.
Deficiencies in four of these nutrients, zinc, selenium, folic acid
and dietary antioxidants, are common in patients with depression.
Zinc levels are lower among patients with depression. In a recent
study, 25 mg zinc supplementation improved depressive symptoms.
Elsewhere it was shown that two months of zinc supplementation, 25
mg/day significantly increased omega-3 levels.
Depressed patients have lower levels of folic acid. There is also
growing clinical evidence that folic acid helps treat depression and
can enhance the effectiveness of antidepressant medications.
At least five studies link low levels of selenium to negative mood.
Selenium deficiency can interfere with the normal conversion of ALA
to EPA and DHA, and results in an increase in the omega-6:omega-3
ratio. Selenium also plays a role in the human antioxidant defense
system.
Omega-3 fatty acids are extremely vulnerable to oxidation reactions.
Dietary antioxidants are known to influence the antioxidant defense
system and can influence omega-3 status. Some evidence suggests that
antidepressant medications may reverse the severity of oxidative
damage in depressed patients.
Conclusion and Recommendations
There is plenty of research evidence that omega-3 fatty acids,
particularly EPA, may alleviate depression in many people. Fish oil
supplements are well tolerated, have almost no side effects, and are
inexpensive. So far, we cannot recommend that you use fish oil to
replace drug therapy, but it would be a good idea to add them to the
therapy. You should see results in about 4 weeks, though the maximum
benefit may not appear until nine months.
Researchers have yet to determine the optimum dosages. Studies have
used between 1-6.4 g of EPA a day. EPA seems to be the omega-3 that
is helping.
Although this is a guess, based upon the current research I would
suggest the following regimen for depression:
-
A fish oil
supplement of 2 g of EPA daily. This can be taken at once or 1 g
twice a day. Alternatively flaxseed oil, which is high in ALA,
can be used. Normally, about 14 g of ALA converts to 2 g of EPA.
-
A general
multivitamin supplement containing high levels of vitamin C,
vitamin E, and about 500 mcg of Folic acid.
-
A general mineral supplement containing selenium. Alternatively,
eating two Brazil nuts a day will provide all the selenium you
need.
Again I want to stress, this regimen is not in place of
medication. However, I suspect that many people who take these
things will need much less medication. Some will be able to get
off medication completely. Even if this regiment does not help
in depression, it may help to prevent or alleviate a number of
other conditions, not discussed here. Best of all there are no
side effects.
Finally, I want to stress that if you or someone you care about
is suffering from depression, this is something you must try.
Though there is still very scanty research, the best run studies
show the EPA is effective in almost 90% of depressed patients.
Given that there are no real side effects to taking fish oil in
contrast to the very serious side effects antidepressant drugs
have, you do not want to wait around for twenty years until the
AMA finally gets around to recommending this treatment.
Anthony Kane, MD
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Essential Fatty Acids
(EFAs)
Essential Fatty Acids (EFAs)
are necessary fats that humans cannot synthesize, and must
be obtained through diet. EFAs are long-chain
polyunsaturated fatty acids derived from linolenic, linoleic,
and oleic acids. There are two families of EFAs: Omega-3 and
Omega-6. Omega-9 is necessary yet "non-essential" because
the body can manufacture a modest amount on its own,
provided essential EFAs are present. The number following
"Omega-" represents the position of the first double bond,
counting from the terminal methyl group on the molecule.
Omega-3 fatty acids are derived from Linolenic Acid, Omega-6
from Linoleic Acid, and Omega-9 from Oleic Acid.
EFAs support the cardiovascular,
reproductive, immune, and nervous systems. The human body
needs EFAs to manufacture and repair cell membranes,
enabling the cells to obtain optimum nutrition and expel
harmful waste products. A primary function of EFAs is the
production of prostaglandins, which regulate body functions
such as heart rate, blood pressure, blood clotting,
fertility, conception, and play a role in immune function by
regulating inflammation and encouraging the body to fight
infection. Essential Fatty Acids are also needed for proper
growth in children, particularly for neural development and
maturation of sensory systems, with male children having
higher needs than females. Fetuses and breast-fed infants
also require an adequate supply of EFAs through the mother's
dietary intake.
EFA deficiency is common in the
United States, particularly Omega-3 deficiency. An ideal
intake ratio of Omega-6 to Omega-3 fatty acids is between
1:1 and 4:1, with most Americans only obtaining a ratio
between 10:1 and 25:1. The minimum healthy intake for both
linolenic (Omega-3) and linoleic (Omega-6) acid via diet,
per adult per day, is 1.5 grams of each. One tablespoon of
flaxseed oil can provide this amount, or larger amounts of
other linolenic-rich foods. Because high heat destroys
linolenic acid, cooking in linolenic-rich oils or eating
cooked linolenic-rich fish is unlikely to provide a
sufficient amount.
EFA deficiency and Omega 6/3
imbalance is linked with serious health conditions, such as
heart attacks, cancer, insulin resistance, asthma, lupus,
schizophrenia, depression, postpartum depression,
accelerated aging, stroke, obesity, diabetes, arthritis,
ADHD, and Alzheimer's Disease, among others.
Omega-3 (Linolenic Acid)
Alpha Linolenic Acid (ALA) is the
principal Omega-3 fatty acid, which a healthy human will
convert into eicosapentaenoic acid (EPA), and later into
docosahexaenoic acid (DHA). EPA and the GLA synthesized from
linoleic (Omega-6) acid are later converted into
hormone-like compounds known as eicosanoids, which aid in
many bodily functions including vital organ function and
intracellular activity.
Omega-3s are used in the formation of
cell walls, making them supple and flexible, and improving
circulation and oxygen uptake with proper red blood cell
flexibility and function.
Omega-3 deficiencies are linked to
decreased memory and mental abilities, tingling sensation of
the nerves, poor vision, increased tendency to form blood
clots, diminished immune function, increased triglycerides
and "bad" cholesterol (LDL) levels, impaired membrane
function, hypertension, irregular heart beat, learning
disorders, menopausal discomfort, itchiness on the front of
the lower leg(s), and growth retardation in infants,
children, and pregnant women.
Found in foods:
Flaxseed oil (flaxseed oil has the
highest linolenic content of any food), flaxseeds, flaxseed
meal, hempseed oil, hempseeds, walnuts, pumpkin seeds,
Brazil nuts, sesame seeds, avocados, some dark leafy green
vegetables (kale, spinach, purslane, mustard greens,
collards, etc.), canola oil (cold-pressed and unrefined),
soybean oil, wheat germ oil, salmon, mackerel, sardines,
anchovies, albacore tuna, and others.
One tablespoon per day of flaxseed
oil should provide the recommended daily adult portion of
linolenic acid, although "time-released" effects of
consuming nuts and other linolenic-rich foods is being
studied, and considered more beneficial than a once-daily
oil intake.
Flaxseed oil used for dietary
supplementation should be kept in the refrigerator or
freezer, and purchased from a supplier who refrigerates the
liquid as well.
Canola oil is often used as a cheaper
alternative to the healthier virgin olive and grapeseed
oils. Although Canola has at least some linolenic content,
supermarket varieties of canola oil are often refined and
processed with chemicals and heat, which destroy much of its
linolenic acid. Cold-pressed, unrefined Canola oil is a
healthier type of Canola (sometimes pricier than virgin
olive oil), and found primarily in health food stores and
specialty markets. The word "canola" is derived from
"Canadian oil", as Canola was developed in Canada from the
rape plant. Rape is a plant in the mustard family, and its
rapeseed oil has at times been illegally blended with olive
oil, particularly in Europe, to cheapen olive oil production
costs. Although rapeseed oil is high in linolenic acid, it
can make humans seriously ill if enough is consumed, and
olive oil cheapened with rapeseed oil has a history of
severely sickening its consumers. (Every feel itchy after
eating commercial brands of peanut butter? Check the label
-- it probably contains rapeseed oil.) Canola was developed
to eliminate chemicals toxic to humans in rapeseed oil, thus
creating an inexpensive oil with linolenic acid. Unlike
olive and flaxseed oil, both known to the ancients and used
as mankind evolved, Canola is a recent oil, and its
long-term effects on humans are not yet known.
Unripe flaxseeds contain a natural
form of cyanide, and home gardeners should be cautious if
trying to grow flax. The seeds must be ripe before
harvesting. If attempting to grow flax at home, consult an
experienced grower.
Omega-6 (Linoleic Acid)
Linoleic Acid is the primary Omega-6
fatty acid. A healthy human with good nutrition will convert
linoleic acid into gamma linolenic acid (GLA), which will
later by synthesized, with EPA from the Omega-3 group, into
eicosanoids.
Some Omega-6s improve diabetic
neuropathy, rheumatoid arthritis, PMS, skin disorders (e.g.
psoriasis and eczema), and aid in cancer treatment.
Although most Americans obtain an
excess of linoleic acid, often it is not converted to GLA
because of metabolic problems caused by diets rich in sugar,
alcohol, or trans fats from processed foods, as well as
smoking, pollution, stress, aging, viral infections, and
other illnesses such as diabetes. It is best to eliminate
these factors when possible, but some prefer to supplement
with GLA-rich foods such as borage oil, black currant seed
oil, or evening primrose oil.
Found in foods:
Flaxseed oil, flaxseeds, flaxseed
meal, hempseed oil, hempseeds, grapeseed oil, pumpkin seeds,
pine nuts, pistachio nuts, sunflower seeds (raw), olive oil,
olives, borage oil, evening primrose oil, black currant seed
oil, chestnut oil, chicken, among many others.
Avoid refined and hydrogenated
versions of these foods.
Corn, safflower, sunflower, soybean,
and cottonseed oils are also sources of linoleic acid, but
are refined and may be nutrient-deficient as sold in stores.
Omega-9 (Oleic Acid)
Essential but technically not an EFA,
because the human body can manufacture a limited amount,
provided essential EFAs are present.
Monounsaturated oleic acid lowers
heart attack risk and arteriosclerosis, and aids in cancer
prevention.
Found in foods:
Olive oil (extra virgin or virgin),
olives, avocados, almonds, peanuts, sesame oil, pecans,
pistachio nuts, cashews, hazelnuts, macadamia nuts, etc.
One to two tablespoons of extra
virgin or virgin olive oil per day should provide sufficient
oleic acid for adults. However, the "time-released" effects
of obtaining these nutrients from nuts and other whole foods
is thought to be more beneficial than consuming the entire
daily amount via a single oil dose.
Food tips
High heat, light, and oxygen destroy
EFAs, so when consuming foods for their EFA content, try to
avoid cooked or heated forms. For example, raw nuts are a
better source than roasted nuts. Don't use flaxseed oil for
cooking, and never re-use any type of oil.
Replace hydrogenated fats (like
margarine), cholesterol-based fats (butter/dairy products),
and poly-saturated fats (common cooking oils) with healthy
EFA-based fats when possible. For example, instead of
margarine or butter on your warm (not hot) vegetables, use
flaxseed and/or extra virgin olive oils with salt. (This
tastes similar to margarine, as margarine is just
hydrogenated oil with salt.)
Sprinkling flaxseed meal on
vegetables adds a slightly nutty taste. Whole flaxseeds are
usually passed through the intestine, absorbing water only
and not yielding much oil. Also, it's best not to use huge
amounts of flaxseed in its meal (ground seed) form, as it
contains phytoestrogens. The oil is much lower in
phytoestrogens.
In many recipes calling for vegetable
shortening, replacing the shortening with half as much
virgin olive oil, and a very small pinch of extra salt,
often yields similar results.
Adding flaxseed and/or virgin olive
oil to salads instead of supermarket salad oil is another
healthy change.
Replace oily snack foods, like potato
chips and corn chips, with nuts and seeds.
Extra virgin olive oil or grapeseed
oil are best to use for cooking oil, as they withstand high
heat well.
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