Flax probably originated in the Middle East, was used in ancient Egypt and was introduced very early in Western Europe.
The use of flax for its textile fibers was already important in the West from the Middle Ages.
The food or medicinal use of the seeds at these times is known but less documented.
Flax is an erect annual plant with light blue flowers, and capsular fruit containing small shiny brown or light yellow seeds, it is adapted to the temperate climate even in cold winter because its vegetative cycle is short (around 100 days).
Canada is thus one of the leading producers of flax (especially for its seeds) with China and the USA.
Selected varieties can adapt to warmer temperate climates.
In France, which for a long time was a major producer of "textile" flax, farmers are now also moving towards the production of flax seeds.
Linseed and extracts of flax are used in medicine, linseed oil for its dietary qualities.
CHEMICAL COMPOSITION AND PROPERTIES
Flax seeds, which are very oleaginous, contain:
- 30 to 40% lipids (fatty substances) rich in polyunsaturated fatty acids,
- 30 to 40% of carbohydrates including soluble and insoluble "dietary fibers" and mucilages,
- 20 to 25% protein,
- minerals and trace elements,
- as well as lignans, phenolic compounds fairly common in plants but particularly abundant in flax seeds (40 to 60 mg per 100 g).
- A very low percentage of slightly toxic substances.
FLAX SEED FATTY ACIDS
The fatty acids of flaxseed lipids have an amazing composition:
- alpha-linolenic acid (omega 3) 45 to 70%,
- linoleic acid (omega 6) 10 to 25%,
- oleic acid 10 to 20%,
- the rest in saturated acids (palmitic end stearic).
We note the quantitative importance of polyunsaturated fatty acids, around 70%.
They are very sensitive to rancidity (oxidation) but reequilibrate the diet generally poor in omega 3 fatty acids.
FLAX SEED CARBS
Most of these carbohydrates cannot be assimilated by the body, so they are useful for giving volume to feces and thus fighting against CONSTIPATION.
A fraction of these carbohydrates is easily hydrated, thus increasing in volume, and becoming mucilaginous, capable of protecting the digestive mucosa of the stomach or intestines, of reducing its inflammation, and of facilitating digestive intestinal transit.
We also now know that the fibrous and mucilaginous plant substances including those of flaxseed limit the intestinal reabsorption of cholesterol, and thus make it possible to fight against HYPERCHOLESTEROLEMIA or certain disorders of blood lipids.
LINGANS OF FLAX SEEDS
Lignans are phenolic compounds present in small quantities in many seeds or almonds (example: legumes such as soybeans, lentils or peanuts, cashew almonds) in fruits (kiwi), green vegetables (cabbage, spinach, carrots ), certain seaweeds, and whole grains (especially triticale, oats or wheat).
But it is in flaxseed that we find the most, 50 times more than in legumes or cereals.
Certain lignans (secoisolariciresinol) are transformed in the intestine by bacteria and absorbed by the body.
These secondary lignans or enterolignans (enterodiol and enterolactone) have a chemical structure which allows them to bind to receptors for steroid hormones, in particular those for estrogen.
They are therefore considered to be PHYTOESTROGENS because they can take the place of female hormones (estrogens), thus blocking their metabolism, their attachment to specific receptors and therefore the effects of natural hormones (for example on the breasts or the prostate) .
Their action on estrogen metabolism is not well known, but pharmacologists believe that lignans can be used as replacement therapy at the start of menopause and in the prevention of certain hormonal-dependent cancers (breast, prostate).
By their phenolic chemical structure, lignans are free radical scavengers and therefore anti-inflammatory.
Some studies suggest that they can decrease the resistance of tissues to insulin and improve type 2 diabetes, other studies that they may lower the risk of developing cardiovascular diseases related to age or to associated disorders (overweight, obesity, diabetes, hypercholesterolemia).
Food grade flaxseed oil is cold pressed.
It can be stored in small opaque bottles, preferably in the cold (fridge).
Industrial linseed oil (paint, varnish, linoleum, mastic) is most often extracted using heat or a solvent to increase the extraction yield, it is not edible.
As we have seen above, flaxseed oil, colored yellow, is unstable because its triglycerides are very rich in polyunsaturated fatty acids, which makes it sensitive to oxidation (polymerisation) in the presence of air (rancidity) , this reaction is accelerated by heat and light.
This polymerisation reaction is useful for paints, varnishes, the impregnation of dry wood or the manufacture of linoleum (drying by polymerization).
flax seeds are better when freshly crushed, in a cereal or spice mill for example (they are then more effective):
- In case of chronic or transient CONSTIPATION without signs of intestinal obstruction or diverticulosis of the colon:
One to two tablespoons of whole or better ground flax seeds in the equivalent of a glass of water, at bedtime for one to two weeks, and the same in the morning if constipation persists.
Another possibility: 2 to 3 tablespoons of seeds in a liter of hot water, wait for them to swell (at least 6 hours), to consume in 3 or 4 times during the day.
- To alleviate the symptoms of IRRITABLE BOWEL SYNDROME, spastic colitis or mucous colitis when the possibility of colonic diverticulosis has been eliminated:
1/2 teaspoon to 1 tablespoon of crushed flax seeds in the equivalent of a glass of water, 3 times a day.
Stop if colic disorders increase (intestinal gas, flatulence or digestive cramps).
We prefer to use psyllium seeds to alleviate irritable bowel symptoms, knowing that diet is important and that mucilaginous seeds only have a positive effect on colitis symptoms in about 30% of cases.
- As a DIETARY SUPPLEMENT to reduce insulin resistance in type 2 diabetes: 40 to 50 g of crushed flax seeds per day incorporated into the food, taking into account the caloric intake of these seeds (approximately 120 Kcal ).
- As a FOOD SUPPLEMENT for omega 3 and 6 intake: approximately 2 teaspoons per day of crushed flax seeds.
Plain or lightly grilled then crushed flax seeds can easily be incorporated into many dishes (soup, sauce, soups, vegetable puree, or even yogurt), pastries, bread, pancakes.
- To prevent cancers of the genital and digestive spheres, to reduce the physiological effects of menopause (hot flashes, vaginal dryness, osteoporosis): these indications are more controversial because the results of the studies are quite divergent.
Note that in certain Amerindian markets of South America (Ecuador and Bolivia) flax seeds are offered to treat female hormonal disorders of menopause, infertility or dysmenorrhea.
- To reduce non-infectious skin inflammation or even certain joint pain: this indication is traditional but has proven its effectiveness, a poultice of fresh flaxseed or crushed flaxseed flour is applied to the inflamed or painful area: 40 to 50 g of crushed flax seeds in boiling water, keep hot for a few minutes and apply the slightly cooled paste on the inflamed area, keep this poultice for a few hours.
Linseed oil has long been consumed in cold regions of Europe where olive oil was scarce or expensive.
But it was little appreciated, because it rancid very quickly.
For several years it has been recommended to reequilibrate the omega3 / omega 6 fatty acid ratio in modern food.
Nutritionists have indeed shown that modern food and "industrial" foods were firstly deficient in unsaturated fatty acids and secondly relatively too rich in omega 6 fatty acids.
This deficit and imbalance of fatty acids in the modern diet is perhaps partly responsible for the increase in the number of degenerative and inflammatory diseases in rich countries.
Linseed oil is preferably available in small opaque bottles or in the form of a swallowable capsule.
In recent years, the French authorities have authorized the marketing of cold-pressed "virgin" linseed oil for human consumption.
Nutritionists advise between 1/2 tablespoon of dessert and 1 tablespoon of linseed oil per day, depending on size, age (avoid in children under 6 years old) and the already existing intake of acids fat in food (fish, almonds or nuts).
You may prefer the more palatable walnut oil.
SOME OTHER USES OF FLAX OR ITS DERIVATIVES
- Textile use: very long, fine and resistant fibers, for the manufacture of fabric but also for many old or more modern uses (stationery, plastic industry and in the building industry).
- Animal feed: the incorporation of seeds or flax meal is now recommended in cattle, horses, pigs, chickens and pets firstly for the good health of the animals and also for the modification of fatty substances in the meat , milk or eggs resulting from it (increase in the percentage of unsaturated omega 3 fatty acids in triglycerides).
- Linoleum: this floor covering based on linseed oil ,that dates back to the 19th century, is natural and healthy (no petroleum products or releasing toxic solvents), hygienic (it has a bactericidal power hence its use in hospitals).
- Flax can be grown in a garden but the seed yield is quite low (between 350 and 700 kg per hectare according to an agronomic document, or on average 50 grams per square meter !!)
FLAX, A TEXTILE AND OLEAGINOUS PLANT WITH MEDICINAL AND DIETARY PROPERTIE
FLAX, a textile plant, used for its long and resistant fibers since antiquity, has interesting oleaginous and mucilaginous seeds to treat inflammation of the digestive mucous membranes (colitis, gastritis, irritable intestine) and constipation.
LINSEED OIL, very rich in omega 3 and 6 fatty acids, cold-extracted from its seeds, is used as a dieteray supplement.
Flaxseed also contains phenolic compounds (lignans) which can replace estrogens (phytoestrogens) in the body.
Copyright 2020 : Dr Jean-Michel Hurtel