Prairie Fare: Some Facts about Flax
By Julie Garden-Robinson, Food and Nutrition
Specialist
NDSU Extension Service, April 12, 2001
In generations past, women soaked flaxseed in water to
release the gummy substance from the seed coat and applied
it as a setting gel to their hair. As a graduate student
I examined the natural coating on flaxseed, but I didn't
use it to help curl my straight hair. I studied it as a
potential food additive and found that it improved loaf
volume and helped delay staling of bread.
Flax has long been the subject of research at North Dakota
State University. Located in the northwest corner of the
NDSU campus in Fargo, Flax Plot No. 30 is on the National
Register of Historic Places. The plot is used for disease
testing and has been planted to flax every year since 1893.
It is considered by many to be the oldest in the world
continuously used for a plant breeding effort. Last year,
North Dakota producers raised 475,000 acres of flax, more
than 90 percent of the flax raised in the United States.
Flaxseed, also known as linseed,
has been studied by nutrition researchers in recent years.
Some have called it a "designer
food," "nutraceutical" or "functional food" because of
its potential health benefits. These small, flat brown
or golden seeds are available in many health or natural
foods stores. Flaxseed may be eaten whole or ground in
a coffee grinder or food processor to produce a meal with
a pleasant nut-like flavor. Whole seeds, however, aren't
digested very well unless they're baked or otherwise heated.
For best quality, whole seeds can be stored at room temperature
for about a year.
The nutrient composition of flaxseed varies with the variety,
growing season and location. Flaxseed primarily contains
protein, fat and dietary fiber. It is an excellent source
of alpha-linolenic acid, a type of omega-3 fatty acid that
some scientists believe may reduce our risk of stroke or
heart disease. Flaxseed oil is available in some stores.
Since flaxseed is high in fat and susceptible to becoming
rancid, it's best to grind it as needed for maximum freshness.
The ground product also may be refrigerated or frozen.
Because flaxseed is approximately one third fat by weight,
ground flaxseed can be substituted for shortening at the
approximate ratio of three parts ground flaxseed for every
one part shortening. If you make substitutions in recipes,
expect some texture and consistency changes in the final
product, and start small. Ground flaxseed can be substituted
for some of the flour in muffins, quick breads or pancakes.
Some scientists have examined compounds in flax known
as lignans, which are phytoestrogens (plant estrogens)
similar to compounds found in soy products. Lignans may
help protect against certain types of cancer (including
cancers of the breast and prostate) and heart disease and
may reduce symptoms of menopause in some women.
Flaxseed contains dietary fiber that
may help control cholesterol levels. In one study, a group
of people with slightly elevated cholesterol levels ate
six slices of wheat bread a day for four weeks and, for
the second four weeks of the study, ate six slices of bread
daily containing 30 percent flaxseed. At the end of the
flaxseed study, the subjects had lowered their LDL cholesterol
("bad cholesterol")
levels by 19 percent and their overall cholesterol level
by 6.9 percent, while not affecting their HDL ("good cholesterol")
levels.
Other researchers have incorporated
10 to 20 percent flaxseed into the diets of laying hens
to change the fat composition of the eggs without adversely
affecting the flavor or other properties. These "designer eggs" are
high in omega-3 fatty acids and are on the market in some
grocery stores.
How much flaxseed is enough -- or too much? If you intend
to incorporate flaxseed in your diet, start with a tiny
amount in case of potential, but rare, allergic reactions.
Most experts have set a safe upper limit of about 25 grams
(about 3 tablespoons) per day. Since the outer coating
on flaxseed also has a laxative effect, that's another
reason to proceed very slowly with perhaps one teaspoon
per day. Raw flaxseed contains cyanogenic glucosides, a
potential toxin in high doses, so the maximum amount used
in research studies has been 50 grams per day.
As with anything, moderation is the key. It's best to
consult a physician or other health practitioner before
making dietary changes particularly if you're being treated
for a medical condition. Don't expect miracles and stop
consuming flax if you have any adverse reactions.
