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(The information on this website is not
a substitute for diagnosis and treatment by a qualified medical practitioner.
We do not advise anyone to stop taking medications without the advice
of a doctor.)
Summaries
of the latest research:
Often, a combination of supplements may
help in alleviating this condition. You may wish to consult a nutritional
therapist for personal advice. Supplements that may be helpful in alleviating
symptoms are shown below:
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also read this important notice concerning supplement medical claims)
(Go to health supplements
appropriate to this subject)
Your brain needs DHA
Professor of Nutrition
in Medicine at Cornell University, Dr Barbara Levine, believes that
postpartum depression, attention deficit hyperactivity disorder (ADHD)
and low IQs are all linked to the dismally low DHA intake common in
the United States. Dr Levine also points out that low DHA levels have
been linked to low brain serotonin levels which again are connected
to an increased tendency to depression, suicide and violence.
Dr Levine
is concerned about the totally inadequate intake of DHA by most Americans.
DHA is the building block of human brain tissue and is particularly
abundant in the grey matter of the brain and the retina. Low levels
of DHA have been associated with depression, memory loss, dementia and
visual problems. DHA is particularly important for fetuses and infants;
the DHA contents of the infant’s brain triples during the first three
months of life. Optimal levels of DHA are therefore crucial for pregnant
and lactating mothers. Unfortunately, the average DHA content of breast
milk in the United States is the lowest in the world, most likely because
Americans eat comparatively little fish. Making matters worse is the
fact that the United States is the only country in the world where infant
formulas are not fortified with DHA. This despite a 1995 recommendation
by the World Health Organization that all baby formulas should provide
40mg of DHA per kilogram of infant body weight.
DHA is
abundant in marine phytoplankton and cold-water fish and nutritionists
now recommend that people consume two to three servings of fish every
week to maintain DHA levels. If this is not possible, Dr Levine suggests
supplementing with 100mg per day of DHA.
Levine, Barbara S. Most
frequently asked questions about DHA. Nutrition Today, Vol.32, November/December
1997 pp.248-49
Fish
consumption and depression
Dr Joseph
Hibbeln, a researcher at the National Institute on Alcohol Abuse and
Alcoholism reports in a letter to The Lancet that he has found
a convincing correlation between fish consumption and the incidence
of major depression. Dr Hibbeln correlated the annual incidence of major
depression per 100 people in nine countries with the consumption of
fish. He found a high incidence of depression in countries with low
fish consumption. New Zealand with an annual fish consumption of only
40 lbs had an annual incidence rate of depression of 5.8 per cent while
Korea with a fish consumption of more than 100 lbs/year had an annual
incidence rate of only 2.3 per cent. Japan with a fish consumption of
almost 150 lbs/year had the lowest incidence of major depression (0.12
per cent). Dr Hibbeln cautions that various economic, social, cultural
and other factors could have influenced his results, but points out
that high blood plasma concentrations of DHA (docosahexaenoic acid),
an essential fatty acid found in fish, has been linked to increased
serotonin turnover and lower incidences of depression and suicide.
Hibbeln, Joseph R. Fish
consumption and major depression. The Lancet, Vol.351, April 18, 1998,
p.1213 (correspondence)
Fish
consumption slows mental decline
A study in the Netherlands
involved almost 1000 men born between 1900 and 1920. The men’s diet
was assessed and cognitive function was evaluated in 1990 and 1993 using
the Mini-Mental State scale. This includes questions on orientation
to time and place, registration, attention and calculation, recall,
language, and visual construction.
The researchers
found that men with the highest intake of linoleic acid (mainly from
margarine, butter, baking fats, sauces, and cheeses) had a 76% higher
degree of cognitive impairment than men with the lowest intake. This
association held true even after adjusting for age, level of education,
cigarette smoking, alcohol consumption and calorie intake.
The intake
of omega-3 fatty acids, on the other hand, was not associated with any
degree of impairment. Men with a high fish intake were less likely to
be cognitively impaired than men with a low intake and their rate of
decline over the period 1990-93 was half that of men with a low intake
and their rate of decline over the period 1990-93 was half that of men
rarely consuming fish.
Kalmijn, S., et al. Polyunsaturated
fatty acids, antioxidants, and cognitive function in very old men. American
Journal of Epidemiology, Vol.145, January 1, 1997, pp.33-41
Docosahexaenoic
acid (DHA) fights depression
Researchers at the National
Institute of Alcohol Abuse and Alcoholism believe that the increasing
rates of depression seen in North America over the last 100 years are
due to a significant shift in the ratio of omega-6 (arachidonic acid,
linoleic acid) to omega-3 (DHA, linolenic acid) fatty acids in the diet.
The human
race evolved on a diet with a ratio of about 1:1 of these acids. It
is now estimated to be between 10:1 and 25:1.
Docosahexaenoic
acid (DHA) is a main component of the synaptic membranes and a lack
of it has been linked to depression.
Fish oils
are a rich source of DHA and it can also be biosynthesized in the body
from linolenic acid (e.g.flaxseed oil).
The researchers
speculate that the depressions which often accompany alcoholism, multiple
sclerosis, and childbirth (postpartum depression) are all due to a lack
of DHA and can be corrected by increasing the dietary intake of DHA
or linolenic acid (flax seed oil). They also point out that depression
and coronary heart disease are strongly associated and that a low intake
of omega-3 fatty acids has been linked to both.
Hibbeln, Joseph R and
Salem, Norman. Dietary polyunsaturated fatty acids and depression: when
cholesterol does not satisfy. American Journal of Clinical Nutrition,
Vol.62, July 1995, pp.1-9
Fish
consumption reduces suicide risk
Researchers at the University
of Kuopio report that regular fish consumption reduces the risk of depression
and suicide. Their study involved 1767 Finnish men and women who were
evaluated for depression and suicidal tendencies using the 21-item Beck
Depression Inventory. They were also asked about their fish consumption.
The researchers conclude that people who consume fish twice a week or
more have a 37 per cent lower risk of being depressed and a 43 per cent
lower risk of having thoughts of harming themselves (suicidal tendencies).
The results
are consistent with those of a large Japanese study involving 265,000
subjects who were followed up for 17 years. This study found a decreased
risk of suicide among people who consumed fish daily. Dr Andrew Stoll,
MD of the Harvard Medical School points out that Icelanders who consume
a lot of seafood have far lower rates of seasonal affective disorder
(SAD) than do inhabitants of other countries situated at similar latitudes.
Both Dr Stoll and the Finnish researchers urge large-scale trials to
conclusively determine whether it is appropriate to recommend increased
fish intake or fish oil supplementation to depressed people or indeed
to the population as a whole.
Tanskanen, Antti, et
al. Fish consumption, depression, and suicidality in a general population.
Archives of General Psychiatry, Vol.58, May 2001, pp.512-13.
EPA helps
schizophrenia
Researchers at the Imperial
College School of Medicine in London report that schizophrenia symptoms
can be eliminated or at least vastly diminished by oral supplementation
with EPA, the major component of fish oils. Their experiment involved
a 30-year-old man who had suffered from schizophrenia for over 10 years.
He had frequent (at least daily) hallucinations and also suffered from
persecutory delusions and thought disorder. The patient was put on 2
grams/day of EPA and was evaluated for schizophrenia symptoms and blood
plasma and red blood cell membrane levels of fatty acids at monthly
intervals for 6 months. The results were spectacular. After 6 months
the overall score for schizophrenia symptoms had dropped by a factor
of 6 (an 85% reduction in severity). Episodes of delusions were completely
eliminated and there was an 88% reduction in the number of hallucinatory
episodes.
Clinical
improvement in symptoms in this case was associated with substantial
increases in the levels of EPA, DHA and AA in red blood cell membranes
and with significant increases in EPA and DHA levels in blood plasma.
The researchers conclude that EPA supplementation is able to reverse
the abnormal fatty acid profiles found in schizophrenics and that this
reversal is associated with, and is likely to be the cause of, the clinical
improvement.
Richardson, A. J., et
al. Red cell and plasma fatty acid changes accompanying symptom remission
in a patient with schizophrenia treated with eicosapentaenoic acid.
European Neurophyschopharmacology, Vol. 10, 2000, pp. 189-93.
Fish
Oil supplementation helps schizophrenia patients
The Cochrane Library,
Oxford, UK, a prestigious medical think-tank dedicated to the development
of evidence-based medicine, has released a review of the evidence concerning
the use of polyunsaturated fatty acids (fish oils and evening primrose
oil) in the treatment of schizophrenia. A wide-ranging literature survey
revealed 4 studies that met the Library’s stringent quality measures.
The most recent study (Shah 2000) included 30 newly diagnosed schizophrenia
patients who were not on antipsychotic drugs at the beginning of the
trial. The patients were randomized to receive either a placebo or a
daily dose of eicosapentaenoate (quantity not specified). At the end
of the 12 weeks all the patients in the placebo group needed to be placed
on antipsychotic drugs. Only 9 of the 15 patients in the active treatment
group needed these drugs after the 12 weeks.
Another
study (Peet 1997) compared evening primrose oil supplementation with
placebo in 43 schizophrenics. The patients’ mental state was not improved
in either the placebo or the treatment group after 12 weeks. A third
study involving 29 schizophrenics compared supplementation with fish
oil to evening primrose oil and found fish oil superior.
The
researchers conclude that fish oils may be useful in the treatment of
schizophrenia and that medical doctors should not discourage their patients
from taking fish oil supplements. They add that fish oils seem to be
well tolerated and free of adverse effects.
Joy, CB, et al. Polyunsaturated
fatty acid (fish or evening primrose oil) for schizophrenia. The Cochrane
Library, Issue 4, 2000.
Dementia
associated with low DHA levels
Dementia now affects
about 47% of the population over 80 years of age in Western countries.
The incidence of Alzheimer’s disease, a leading cause of dementia, is
growing especially rapidly. There is no cure for Alzheimer’s disease
(AD) and it is not at all clear what causes it. Researchers at the University
of Guelph now report that they have found low levels of long-chain polyunsaturated
fatty acids, notably DHA , in people suffering from Alzheimers Disease
and dementia.
The
study involved 84 people (aged 80 years or older) who were given a thorough
clinical evaluation. Nineteen of the people were diagnosed as having
Alzheimers, 10 as having non-Alzheimers dementia, 36 were characterised
as non-demented but cognitively impaired, and 19 had normal cognitive
functioning. Blood samples were obtained from all participants and analysed
for fatty acids. The researchers observed significantly lower levels
of EPA (by about 42%), DHA (by 17-33%) and total omega-3 fatty acids
(by 23-28%) in the blood of patients with Alzheimers Disease, other
dementia and cognitive impairment (non-demented) than in normal controls.
DHA is highly concentrated in the cerebral cortex and a deficiency in
blood plasma is likely to translate into a deficiency in the brain.
Other
research has confirmed the association between low DHA and EPA levels
and impaired cognitive function. Other studies have found that fish
oil supplementation improves mood, cooperation, appetite, sleep, and
short-term memory in Alzheimer patients. The Guelph researchers conclude
that an effort should be made to increase the intake of fish or fish
oils in the population at large and the elderly in particular.
Conquer, Julie A., et
al. Fatty acid analysis of blood plasma of patients with Alzheimer’s
disease, other types of dementia, and cognitive impairment. Lipids,
Vol.35, Deember 2000, pp.1305-12
Omega-3
fatty acids: the missing link?
Dr Emanuel Severus of
the Berlin University finds that major depression is characterised by
a deficiency of omega-3 fatty acids and that these acids possess powerful
anti-arrhythmic properties. He suggests that the missing link in the
recently established association between major depression and sudden
cardiac death may be the omega-3 fatty acid deficiency which characterises
both conditions.
Severus, W. Emanuel,
et al. Omega-3 fatty acids: the missing link? Archives of General Psychiatry,
Vol.56, April 1999, pp. 380-81 (letter to the editor)
Low docosahexaenoic
acid (DHA) levels and Alzheimer’s disease
DHA, a major component
of fish oils, is the most important fatty acid in the brain and retina
and makes up more than 30% of the structural lipid (fat) in neurons.
There is ample evidence that a deficiency of DHA is associated with
depression, attention deficit hyperactivity disorder, and dementia.
Clinical studies have shown that an increased intake of DHA may benefit
patients with dyslexia and Alzheimer’s disease.
Researchers
at Boston University and Tufts University School of Medicine now report
that they have found a clear association between low blood levels of
DHA and the risk of developing Alzheimer’s disease. Their study involved
1188 Americans (mean age of 75 years) who had blood samples drawn and
analysed for DHA in 1985. Sixteen of the participants had clinically
diagnosed Alzheimer’s at the time of blood sampling. The researchers
noted that 11 of the 16 (69%) had DHA levels in the lower half of the
DNA distribution. The remaining 1172 participants were followed for
10 years. Again the researchers noted that participants with DHA levels
in the lower half of the distribution had a 67% greater risk of developing
Alzheimer’s disease. The researchers suggest that maintaining adequate
levels of DHA through the consumption of fish or dietary supplements
rich in DHA may be particularly important for the elderly.
Kyle, D. J., et al. Low
serum docosahexaenoic acid is a significant risk factor for Alzheimer’s
dementia. Lipids, Vol.34 (suppl), 1999, p.S245.
Fish
oils and manic-depressive illness
Manic-depressive illness
(bipolar disorder) is a common, severe mental illness involving repeated
episodes of depression, mania (rapid mood changes, hyperactivity, and
excessive cheerfulness) or both. It is usually treated with drugs such
as lithium carbonate or valproate. Unfortunately, these drugs are not
very effective and recurrence rates are high. It is generally believed
that bipolar disorder involves an overactivity in the neuronal signal
pathways. Omega-3 fatty acids are known to dampen this overactivity
and medical researchers at the Harvard Medical School have confirmed
that omega-3 oils may be useful in the treatment of bipolar disorder.
The double-blind,
placebo-controlled study involved 30 patients (men and women 18 to 65
years of age) who had all been diagnosed with bipolar disorder. Half
the patients were given seven fish oil capsules twice a day while the
placebo group were given seven olive oil capsules twice a day. Each
fish oil capsule contained 440mg of eicosapentaenoic acid and 240mg
of docosahexaenoic acid. All of the participants except four in the
fish oil group and four in the placebo group also continued to receive
a standard mood-stabilizing drug prescribed previously. The mental state
of the participants was measured using four scales (Clinical Global
Impression Scale, Global Assessment Scale, Young Mania Rating scale,
and the Hamilton Rating Scale for Depression) at the start of the study
and after two, four, six, eight, twelve and sixteen weeks. Twelve of
the 14 participants in the fish oil group completed the four-month study
without major episodes of mania or depression as compared to only six
out of 16 participants in the placebo group. Also, while nine of the
placebo group members experienced worsening depression none of the fish
oil group members did. The four patients in the fish oil group who had
not been prescribed mood-stabilizing drugs all completed the study without
major episodes, but only one member in the placebo group not on mood-stabilizing
drugs did. The average decline in depression rating on the Hamilton
Scale was almost 50 per cent in the fish oil group as compared to an
increase of 25% in the control group. The Harvard researchers urge further
trials of fish oils in the treatment of depression and manic-depressive
illness.
Stoll, Andrew L. et al.
Omega 3 fatty acids in bipolar disorder. Archives of General Psychiatry,
Vol.56, May 1999, pp.407-12 and pp.415-16 (commentary)
Recommended Supplements
containing DHA and EPA:
(back
to top)
Nutri Eskimo-3 Stable Fish Oil
BioCare
Mega EPA 1000mg (EPA/DHA fish oil concentrate)
Se also our article:
Is depression
a dietary problem?
(The
information on this website is not a substitute for diagnosis and treatment
by a qualified medical practitioner. We do not advise anyone to stop
taking medications without the advice of a doctor.)
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