From the November 1996 issue of Nutrition Science News
Excess calories, not fat, cause obesity, and essential fatty
acids are crucial to maintaining health.
"Save your heart-eat less fat." This is a fallacy believed by
many. People follow the simplified formula by eating
traditionally low-fat foods such as bread, pasta and cereal.
Manufacturers supplement consumer buying trends with low-fat
cookies, crackers and treats.
Statistics show that Americans are fatter than ever and no closer
to avoiding heart disease than they were before the no-fat craze.
Mainly this is because excess calories, not fat, cause obesity
and its slew of health hazards-a detail that got lost somewhere
between the lab and the food store. It's also because most
consumers are replacing their fats with carbohydrates.
Carbohydrates do have less calories than fat, but a constant diet
of them can still lead to weight gain. All the extra calories in
bread and pasta that aren't used for energy are converted into
fat and stored in the body, just like a hamburger would be. Even
more problematic is that without the proper safeguards, a low-fat
diet may also put people at risk for serious health problems such
as cardiovascular disease, stroke and atherosclerosis.
The Role Of Fats
The link between high-calorie foods (including saturated fats)
and heart disease is long established. But swearing off all fats
isn't the answer. Some fats are good for you, especially the
essential fatty acids (EFAs) found in certain plants, seeds, oils
and cold-water fish.
Studies have shown that consuming a diet rich in fish oil not
only helps to lower blood cholesterol, triglycerides and
low-density lipoproteins (LDL, the bad cholesterol), it also
raises levels of beneficial high-density lipoproteins (HDL, the
good cholesterol). EFAs also help regulate cellular oxygen use,
electron transport, energy production, hemoglobin formation,
blood pressure, cholesterol transport and immune functions.
Unaware of the importance of EFAs, many consumers confuse them
with fats that really are bad for their health.
There are three types of fat: saturated, monounsaturated and
polyunsaturated. Each is a mixture of different fatty acids, and
each plays an important role in the body after it's ingested. The
specific amount of each fatty acid and its respective molecular
structure determine whether the fat is a solid or liquid.
Saturated fats such as beef fat and hydrogenated oils form solids
at room temperature because they are straight molecules.
Monounsaturated fats, including olive oil, have one "kink" or
bend in their structure and remain liquid (except in the
refrigerator). The body can make both saturated and
monounsaturated fats, so they are called nonessential.
Polyunsaturated fats are a different story. Even in the
refrigerator they remain liquid because of two kinks in their
molecular structure. The human body can't manufacture
polyunsaturated fats; they must be supplied by dietary sources.
Only two types of polyunsaturated fatty acids are considered
essential: omega-6 (called linoleic acid or LA) and omega-3
(called alpha-linolenic acid or LNA). Other important fatty acids
that aren't essential are derived from EFAs. Gamma-linolenic acid
(GLA) and arachidonic acid (AA) are both made from linoleic acid,
while eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
are derived from alpha-linolenic acid.
Essential fatty acids are nutritionally important because they're
precursors to a group of hormone-like compounds known as
prostaglandins, thromboxanes and prostacyclins that help regulate
the central nervous system, blood pressure and heart rate. EFAs
are also required to make phosphatides, the main structural
components of all cell membranes.
Omega-3 and omega-6 fatty acids generally promote the production
of PGE3- and PGE1-series prostaglandins that are
anti-inflammatory in nature. These forms of prostaglandins help
keep blood platelets from sticking together, open up blood
vessels and slow down cholesterol production. They may also help
prevent cancer cell growth by regulating the rate of cell
Arachidonic acid, found mostly in animal foods but also derived
from omega-6 fatty acids, produces PGE2-series prostaglandins
that are inflammatory in nature-promoting blood clotting, blood
vessel restriction and salt retention, which can lead to water
retention and high blood pressure. These are valuable functions
under survival conditions; however, under chronic stress they
become detrimental. A good supply of omega-3 fatty acids counters
overproduction of AA in the body and helps strike a healthy
balance between the different types of prostaglandins.
Beyond Heart Disease
The list of EFAs' health benefits keeps growing. In addition to
lowering the risk of heart disease, EFA supplements have proven
beneficial in the treatment of a wide range of conditions
including allergies, inflammation, ulcerative colitis and
For example, omega-3 EFA is helpful in treating rheumatoid
arthritis, a disease characterized by pain and inflammation. In
1985, after animal studies conducted at Harvard University in
Cambridge, Mass., indicated that EFAs help protect the body
against attacks by its own immune system (i.e., arthritis), Joel
Kremer, M.D., associate professor of medicine at Albany Medical
College in New York, conducted a controlled experiment using
EFAs. Kremer found that fish oil supplements significantly
improved the health of people with rheumatoid arthritis. "Those
taking fish oil had only about half the number of tender joints
as they had prior to the study," he reported.
Essential fatty acid supplements can also result in gradual
weight loss among people who are genetically obese. Although it's
unclear how the weight loss occurs, it may be linked to EFAs'
ability to "trigger" brown fat, the most metabolically active
form of fat, to maintain a high heat-producing rate of
Getting The Right Fats
Even diets full of polyunsaturated fats can be unhealthy.
Deep-frying damages EFAs, and food-processing methods such as
hydrogenation change polyunsaturated fats into more saturated
fats. Done to promote shelf-stability, the process also creates
detrimental trans fatty acids-thought to both raise cholesterol
and crowd out EFAs in the cells. Probably the least expensive way
to supplement the diet with a good source of EFAs is to eat more
cold-water fish, whole grains, good quality nuts and seeds,
dark-green leafy vegetables, and soybeans; cook with good quality
vegetable oils; and incorporate small amounts of supplemental
oils in meals.
Although supplemental oils vary in their essential fatty acid
content, all can exert healthful effects. Store-bought, extracted
EFA oils including flaxseed, borage and evening primrose oils are
easily oxidized (which results in trans fatty acids), so they
should never be heated and are best stored in the refrigerator
and consumed by the expiration date. Following is a list of some
supplemental oils that are good sources of EFAs:
Fish Oil: Cold, saltwater fatty fish such as
herring, cod, mackerel, sardines and tuna are excellent sources
of essential fatty acids. When given in supplement form, fish
oils rich in the omega-3 fatty acids EPA and DHA have produced
changes in blood platelets associated with a reduced risk of
heart disease. Omega-3 fatty acids also help reduce the blood's
tendency to clot.
DHA: Often called "brain oil," DHA is the
oil to hit the market. This particular fatty acid, derived from
cold-water fish such as tuna and salmon, reportedly reduces blood
cholesterol without the side effects of blood clot prevention.
Researchers also document its ability to inhibit certain cancers
and heart disease as well as aid brain function.
Flaxseed (Linum usitatissimum): A rich,
oil derived from seeds of the fibrous flax plant, flaxseed oil
contains both LA and LNA and is one of the richest sources of
omega-3 fatty acids. Flaxseed oil is also a good source of
lecithin and phosphatides, which aid in the digestion of fats and
oils. It's a good vegetarian supplement for people with omega-3
deficiency-related fatty degeneration.
Evening Primrose (Oenothera biennis): Used for
healing by North American natives, the evening primrose plant was
soon sent back to Europe by the colonists, where it was dubbed
the "king's cure-all." It's been shown to significantly reduce
the painful symptoms of rheumatoid arthritis and certain
autoimmune diseases. Rich in GLA and other omega-6 fatty acids,
evening primrose oil has proved effective in reducing the
itchiness associated with atopic eczema. It's also used to treat
PMS, allergies, depression, colitis and liver degeneration.
Borage (Borago officianalis): Used during the
Ages to ensure blood quality, borage oil was later recommended
for depression and heart strength. It's derived from borage plant
seeds and is high in GLA, an omega-6 fatty acid. It's been used
in conjunction with arthritis, allergies, multiple sclerosis,
cancer and PMS.
Pumpkin Seed (Cucurbita pepo): Pumpkin seeds
a dark green oil that has been used throughout history in India,
Europe and America to nourish and heal the digestive tract, fight
parasites, heal prostate disorders and help prevent dental
cavities. It contains slightly more omega-3 fatty acids than
omega-6, making it one of the most nutritious oils. Pumpkin seed
oil is also recommended for pregnant and lactating women because
of its high EFA content.
Wheat Germ: Wheat germ oil contains
acid (LNA) and is also a good source of a 28-carbon fatty alcohol
(octacosanol), which protects heart function and may help nerve
regeneration. It's also one of the richest sources of vitamin E
and is often used externally for burns, sores and other skin
It is important that your customers and clients don't swear off
fats completely, particularly EFAs. As seen above, essential
fatty acids are nutritionally important for the numerous roles
they play in maintaining healthy body functions. Fortunately,
nature has provided an abundance of foods that contain EFAs.
Adding them to the diet can provide an initial defense against a
whole host of diseases.
This article is compiled from information that appeared in the
book Essential Fatty Acids in Health and Disease by Edward
Siguel, M.D., Ph.D., (Nutrek Press, 1994) and two articles that
ran in Delicious! Magazine: "The Fats That are Good for You,"
October 1996, vol. 12, number 10, and "A New Generation of
Healthy Oils," January 1996, vol. 12, number 1.
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Braly, J. & Torbert, L. Dr. Braly's Food Allergy and Nutrition
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Siguel, E. Essential Fatty Acids in Health and Disease. Nutrek
Press: Brookline, MA, 1994.
Erasmus, U. Fats That Heal, Fats That Kill. Alive Books: Burnaby,
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Finnegan, J. The Facts About Fats. Celestial Arts: Berkeley, CA,
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