are Omega-3 fatty acids?
The three types of
omega-3 fatty acids involved in human
physiology are α-linolenic acid
(ALA) (found in plant oils), eicosapentaenoic
acid (EPA), and docosahexaenoic acid
(DHA) (both commonly found in marine
oils). Marine algae and phytoplankton
are primary sources of omega-3 fatty
acids are named by the location of
the first double bond, counted from
the methyl end, that is, the omega
(ω-) or the n- end. Omega
3 fatty acids are polyunsaturated
fatty acids (PUFAs) with a double
bond (C=C) at the 'third carbon atom'
from the end of the carbon chain.
There are 11 different types
of Omega-3 fatty acids. The three
most important ones are EPA, DHA and
Omega-3 fatty acid--In chemical
structure, EPA is a carboxylic acid
with a 20-carbon chain and five cis
double bonds; the first double bond
is located at the third carbon from
the omega end.
Omega-3 fatty acid-- is a
carboxylic acid with a 22-carbon chain
and six cis double bonds with the
first double bond located at the third
carbon from the omega end. DHA is
one of the more important of the Omega-3's:
the majority of the omega-3 fatty
acids in both the brain (97%) and
the retina (93%) are made of DHA.
DHA is a key component in the heart,
has anti-inflammatory properties.
Omega-3 fatty acid-- is an
essential fatty acid (along with linolenic
acid) that cannot be produced by the
body and must be aquired through diet.
ALA (α-Linolenic acid) is a
carboxylic acid with an 18-carbon
chain and three cis double bonds.
The first double bond is located at
the third carbon from the methyl end
of the fatty acid chain
of Omega-3 Fatty Acids in Health
Humans are unable
to synthesize omega-3 fatty acids,
but can obtain the shorter-chain omega-3
fatty acid ALA (18 carbons and 3 double
bonds) through diet and use it to
form the more important long-chain
omega-3 fatty acids, EPA (20 carbons
and 5 double bonds) and then from
EPA, the most crucial, DHA
(22 carbons and 6 double bonds). The
ability to make the longer-chain omega-3
fatty acids from ALA may be impaired
Some research suggests
that the anti-inflammatory activity
of long-chain omega-3 fatty acids
may translate into clinical effects.
most notably, these include cardiovascular
diseases, inflammatory bowel disease
(IBD), cancer, and rheumatoid arthritis,
but psychiatric and neurodegenerative
illnesses are other examples.
An omega-3 fatty acid
known as docosahexaenoic acid, or
DHA, seems to reverse the harmful
changes produced by fructose. (See
Notes on DHA -- DHA
strengthens synapses in the brain
and enhances learning and memory.
It is abundant in wild salmon (but
not in farmed salmon) and, to a lesser
extent, in other fish and fish oil,
as well as walnuts, flaxseed, and
fruits and vegetables.
DHA is the most abundant
omega-3 fatty acid in the brain and
retina. DHA comprises 40% of the polyunsaturated
fatty acids (PUFAs) in the brain and
60% of the PUFAs in the retina. Fifty
percent of the weight of a neuron's
plasma membrane is composed of DHA.
DHA is richly supplied during breastfeeding,
and DHA levels are high in breastmilk
regardless of dietary choices.
deficiency is associated with cognitive
Foods have the most amounts of Omega-3
total omega-3 values-- Grams of omega-3
per 3oz serving: Flaxseed 11.3, Walnuts
3.0, Sardines and Herring 1.3-2.0,
Salmon 1.1-1.9, Mackerel 1.1-1.9,
One-quarter cup of flaxseeds contains
about 6.3 grams of omega-3 fatty acids
while one-quarter cup of walnuts contains
about 2.7 grams. In either case, the
amount is pretty substantial. Therefore
by combining one-quarter cup of walnuts
with a tablespoon of flaxseeds you
will add close to the recommended
4 grams of omega-3 fats to your diet.
(See Reference 4)
on DHA--"DHA is mainly found
in animal products such as fish, eggs
and meats. Oily fish, such as mackerel,
herring, salmon, trout, sardines,
pilchards, are the richest dietary
source of EFAs, containing 10 to 100
times more DHA than non-marine food
sources such as nuts, seeds, wholegrains
and dark green, leafy vegetables."
Fatty Acids: An Essential Contribution
Fatty Acids -- MedlinePlus
and Omega-3 Fatty Acids
can I get more omega-3 fatty acids
in my daily meals?
-- Brain Food