When "Fatty" is Good: Omega-3 Oils and Fatty Acids
by Wyn Snow, Managing Editor
the rush to cut calories, reduce cholesterol intake, and avoid saturated
fats, many Americans have embraced low-fat diets and low-fat foods.
But some fats are necessary and "essential" for health. These fats
show great promise for fighting the onslaught of heart disease and
diabetes, possibly even cancer. What are these "good" fatsand
how do we get enough of them?
are two varieties of "essential" fatty acids. They are called essential
because, like vitamins, the body needs them and cannot make them.
Thus, we need to be sure we get enough from our diets or from supplementation.
fatty acids are found in many vegetable oils. With the dietary switch
from cholesterol-laden animal fats to vegetable oils, Americans
now get plenty of omega-6 fatty acids in their diet.
fatty acids are found predominantly in cold-water fish and a few
vegetable oils (flaxseed, walnut and canola). Other food sources
of omega-3s include whole grains, legumes, nuts, and green leafy
are Omega-3s so vital to health?
fats in general have multiple uses in the body, their most significant
roles involve the brain, cell membranes, and a host of hormone-like
substances that act like thermostats in the body: either raising
or lowering a variety of metabolic functions in order to maintain
brain is made of fat, especially the omega-3 fatty acid DHA, so
obtaining sufficient omega-3 is crucial for cognitive functioning
the cell membranes in the body are made of cholesterol and fat.
Part of the membrane must be sturdy so the cell can maintain its
shape. For this purpose, the body uses cholesterol and saturated
fatty acids that are straight and can be stacked tightly together.
rest of the membrane must be flexible and porous, so that nutrients
can enter the cell and waste products can leave. To accomplish this,
the body uses unsaturated fats because they are bent. (Read more
of Fatty Acids.)
trans-fats are bad for health
are destructive to health because the body misreads them. Trans-fats
have the same chemical signature as omega-3s and omega-6s, so the
body uses them for the same purposes. But they are structurally
straight rather than bent, so the part of the cell membrane that
needs to be porous becomes tight and rigid instead. This causes
a variety of health problemsincluding insulin resistance,
which can lead to type 2 diabetes.
of trans-fats also raises the risk of heart disease by increasing
LDL and lowering HDL cholesterol. (A useful mnemonic: the levels
one wants to see on test results match the letters: low LDL and
of Omega-3s in metabolic processes
addition to their value for cell membranes, omega-3 fatty acids
play an important role in regulating the body's metabolic processes.
Eicosanoids are hormone-like compounds that act like thermostats
throughout the body, either raising or lowering a wide range of
have only been discovered recently because their action is localized
rather than originating from a specific gland, such as the pancreas
or adrenals. Eicosanoids are composed entirely of omega-3 and -6
typically come in pairs: one to increase and the other to decrease
whatever bodily function the pair is regulating. When omega-3s are
lacking in the diet, the body produces less of one of the pairs,
with the result that these internal thermostats don't work correctly.
The body spirals uncontrollably in a single direction.
of today's chronic diseases are related to the impact of an imbalance
in the omega-6 and omega-3-based eicosanoids. Having higher levels
of omega-6s tends to increase the risk of many inflammatory and
auto-immune diseasessuch as rheumatoid arthritis, lupus, psoriasis,
ulcerative colitis, osteoporosis, gum disease, asthma, and Alzheimer's
diseaseor make these problems harder to treat.
benefits of Omega-3s
fatty acids are vital for our health in a variety of ways.
risk of heart diseaseOmega-3s are blood thinners
and help to keep arteries elastic and flexible. They reduce high
blood pressure, and keep triglycerides down.
risk of unwanted blood clotsOmega-6 based thromboxane
aids in clotting, which stops blood loss from injuries. Omega-3s
keep thromboxane in check, thus preventing unwanted blood clots
that can cause strokes, heart attacks, deep-vein thrombosis and
embolisms in lungs.
blood pressureThromboxane also constricts arteries,
leading to raised blood pressure. Omega-3s again keep thromboxane
inflammatory diseasesOmega-3s are natural anti-inflammatory
agents, so they act to prevent or reduce symptoms of arthritis,
migraine headaches, menstrual cramps, and asthma.
are valuable both for the retina and blood supply through the
tiny capillaries in the eyes.
and moodOmega-3s are an important constituent
of the brain, especially DHA. In cultures that eat a lot of fish,
the rate of depression is lower than in populations that don't,
such as the US. Even though depression has many causes, making
sure the brain has enough nutrients to function well is an obvious
reduce the risk of cancer. They strengthen the immune system,
which is the body's primary defense against the appearance of
new cancerous cells. Omega-3s also make it harder for a tumor
to metastasize to other areas of the body.
risk of osteoporosisBones are living tissue,
constantly being broken down and rebuilt. Eicosanoids help to
regulate the balance between osteoclasts, which break down bone,
and osteoblasts, which rebuild it. Research indicates that healthy
omega-3 levels contribute to rebuilding bone rather than losing
health conditions that can be aided by a healthy intake of omega-3s
are dry skin (one of the first signs of an omega-3 deficiency),
allergies, menopause symptoms, vulnerability to glaucoma and macular
degeneration, chronic inflammatory bowel diseases, and ADHD.
much Omega-3s do we need?
experts disagree both on how much we need, and the optimal ratio
between omega-6 and omega-3 fatty acids. Some recommend consuming
equal quantities (a 1:1 ratio), while others recommend no more than
10 omega-6s to each omega-3. The diet of our Paleolithic ancestors
probably ranged from equal quantities to a 5:1 ratio between omega-6
and omega-3 fatty acids. In Japan, the traditional soy-and-seafood-based
diet shows a ratio of 2.8 to 1. However, the current American diet
contains roughly ten to twenty times as much omega-6 as omega-3
to Paul Thomas, RD and editor of The Dietary Supplement newsletter,
"Most Americans eat diets that provide less than 100 mg/day of EPA
and DHA. The national Food and Nutrition Board has established an
'adequate intake' level of 110 mg for adult women and 160 mg for
adult men. Other nutrition experts advise a more generous intake
of 500-1,000 mg/day from food if possible but from supplements if
needed. People with heart disease, various mental illnesses, and
rheumatoid arthritis may benefit from higher amounts but should
discuss the matter with their healthcare providers first."
Council for Responsible Nutrition, a supplement industry trade organization,
points out that the American Heart Association recommends consuming
two fish dinners a weekwhich is roughly 3 to 4 times more
than the Food and Nutrition Board has characterized as "adequate".
The World Health Organization and various countries around the world
recommend daily intakes averaging 300-500 mg/day of EPA plus DHA.
Dr. Artemis Simopoulos, an expert on omega-3s, recommends getting
an average of 1,000 mg/day.
more omega-3 fatty acids to one's diet is easy to doif one
likes fish. While salmon is the best source at 1700 mg per 3-ounce
serving, even cod supplies 100 mg. (See sidebar: Amount
of Omega-3s in Fish.)
some people dislike fish or are allergic, and others should either
avoid fish or limit their consumption because of the danger of ingesting
mercuryparticularly pregnant women and nursing mothers. Mercury
is especially toxic to the brain and nervous system of babies and
is the best source of omega-3s in the vegetable kingdom. One rounded
tablespoon of milled flaxseed (or one teaspoon of flaxseed oil)
supplies 2000 mg of the omega-3 alpha-linolenic acid (ALA), the
essential fatty acid that humans cannot make. Flaxseed also contains
valuable cancer-fighting lignans (although the oil does not).
food sources of omega-3 fatty acids include walnuts, Brazil nuts,
butternuts, chia seeds, hickory nuts, macadamia nuts, roasted or
cooked soybeans, soybean sprouts, beans of various types, peanuts,
olives, spirulina, spinach, purslane, oat germ, wheat germ, lamb,
pork, Roquefort and cheddar cheese. Of these, purslane and walnuts
are the best sources.
Paul Thomas recommends, "When supplementing with EPA and DHA, choose
fish-oil products concentrated in these omega-3 fatty acids. Strict
vegetarians will need to buy an algae-derived DHA supplement. At
moderate levels of supplementation, EPA and DHA appear to be free
of side effects, though they may cause fishy-tasting belches."
supplements and flaxseed oil are both very vulnerable to becoming
rancid, and should be kept in the refrigerator. Flaxseed oil should
have a "mellow" nutty taste. When it is rancid, it tastes bitter.
factors are blamed for today's epidemic of heart disease, diabetes,
and cancer. Until recently, medical professionals paid little or
no attention to omega-3 fatty acidsyet their consumption by
Inuit peoples has protected them from the usual effects of high-fat
diets, and many Americans consume less than the rather minimal "adequate
intake" level recommended by the national Food and Nutrition Board.
growing incidence of obesity has led Americans to focus on cutting
as much fat as possible from their dietsincluding the heart-healthy
omega-3s. At the same time, the shift to vegetable oils has created
a huge deficit of the omega-3 eicosanoids that function as thermostats
to stop inflammatory processes in the body. The rampant use of trans-fats
(in margarines, partially hydrogenated shortening, and deep-fat
frying of fast-foods with vegetable oils) has clogged our cell membranes
with unhealthy fats, making them more prone to insulin resistance
and the risk of type 2 diabetes.
these epidemics of obesity, heart disease, diabetes and cancer be
reversed by restoring omega-3 fatty acids to our diets in healthy
quantities? Where diet is concerned, there is no such thing as a
single "magic bullet" to banish disease (aside from specific deficiency
diseases such as rickets and scurvy). But where variety and moderation
are the keys to health, we have nothing to lose and everything to
gain by obtaining an abundant supply of omega-3 fatty acids.
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Simopoulos and J Robinson. The Omega Plan: The Medically Proven
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Barlean's Organic Oils, Ferndale WA (www.barleans.com/index.html).
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all the terms, but what do they mean?" www.karmanos.org/answers/nutrition/decipheringfats.html.
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