Flaxseed, or linseed, refers to the seeds of the common flax, Linum usitatissimum. There are two main varieties of flaxseed: brown flaxseed and golden flaxseed.
What does flaxseed taste like? Fortunately it doesn’t taste as bad as it smells, which depending on storage can be quite unpleasant. Flaxseed has a nutty, somewhat oily taste when eaten whole. The seeds are so rich in essential omega-3 fatty acids (alpha-linoleic acid or ALA) that you should always buy and store them whole rather than ground or crushed. This is because fatty acids quickly develop a rancid taste and the nutrients within flaxseed lose their positive effects when ground.
Flaxseeds are flat, brown or golden seeds. Golden flaxseed gels better and tastes milder than brown flaxseed. While flaxseed has a nutty taste, it tends to be consumed for health reasons. You can add small quantities to practically any dish.
Flaxseed is a popular muesli ingredient and is often found in bread and other baked goods. Flax flour can be used as a partial substitute for other types of flour. Crackers, wraps, pancakes, and even pizza dough can be made from flaxseed meal. Ground flaxseed is furthermore a good vegan substitute for eggs in recipes that require a binding agent. To make a binding agent, mix one part flaxseed with three parts water. Flaxseed is also a healthy topping in soups and smoothies. If you grow the seeds for a few days, the sprouts make a great addition to raw salads.
What is the proper way to consume flaxseed? Flaxseed has proven to be a household remedy for gastrointestinal illnesses. When consuming for this purpose, pour hot water over flaxseed and eat this porridge several times a day. If you are eating flaxseed to help with digestion, it is best to eat them whole so that they act as a dietary fiber while still producing mucilage. When flaxseed is crushed or ground, however, the body can better absorb healthy ingredients such as omega-3.
Flaxseed naturally contains small amounts of prussic acid and the heavy metal cadmium, so only relatively small portions of flaxseed should be consumed daily. Heating reduces the content of prussic acid. Higher temperatures partially destroy the enzyme (beta-glucosidase) that activates cyanogenic glycosides to form prussic acid salts. Flaxseed absorbs a lot of liquid and expands when ingested, so make sure you’re drinking plenty of water when consuming flaxseed.1,2
The tender, soft, tangy leaves and shoot tips from the common flax can be eaten raw or used in salads, herb mixtures, or vegetable fillings.3
For one tray of pizza, first soak 15 g of chia seeds in 150 mL of warm water for 30 minutes to create chia gel. Mix this gel with 100 g of crushed flaxseed, 50 g of coconut flour, and 50 mL of water, and season with salt and oregano. Leave the mixture to gel for another 15 minutes. Place the mixture on a baking sheet lined with baking paper and bake for 10 minutes in a pre-heated oven at 200 °C. Top with your favorite ingredients and bake for another 10 minutes.
Sprout two tablespoons of flaxseed in a sprouting jar for about 3 days, watering regularly. Cut one scallion into rings and 100 g cherry tomatoes into quarters and cube one avocado and place all three in a bowl. Add 150 g cooked black beans. For the dressing, mix 2 tablespoons flaxseed oil with 2 tablespoons lemon juice and 1 teaspoon mustard. Toss the salad. Season with salt and pepper as well as fresh basil. Garnish with the sprouts. Best served fresh.
Add 2 heaping teaspoons of whole flaxseed to 250 mL cold water and steep for 20 minutes. Stir occasionally to ensure that the flaxseed gels well. Pour through a strainer and warm up the tea before drinking.
Flaxseed is an ingredient in the gluten-free, raw vegan Erb Muesli. This muesli mix not only contains citrus fruits rich in vitamin c and berries with antioxidants, it also contains pseudograins, seeds, and golden millet. You can also try the version Erb Muesli with Rolled Oats! Choose organic!
Flaxseed can be found in all major grocery stores and health food shops, such as Walmart, Whole Foods Markets, Kroger, and Safeway (United States); Asda, Sainsbury’s, Tesco, Aldi, Lidl, and Holland & Barret (Great Britain); Metro, Extra Foods, and Goodness Me (Canada); Coles, Woolworths, and Harris Farm (Australia). You can also buy flaxseed on Amazon. You will often have the choice between whole and ground flaxseed.
Flaxseed is harvested in August and September, but it can be found in store all year round. If you are looking for residue-free flaxseed, we recommend that you buy certified organic flaxseed. Finding regionally cultivated flaxseed is also important for ecological sustainability.
Flaxseed is usually cultivated and is rarely found in the wild. The flax plant is typically 80 to 120 cm tall with thin, grey-green leaves that are up to 2.5 cm long. Its flowers are plate-shaped and typically sky-blue, or sometimes white. The seeds develop from these flowers.4 It is an annual plant, with a main blossoming period of June to August.3
In addition to the seeds, the flax plant’s leaves and shoot tips can be used in cooking. These parts can typically be harvested from April to June. Although finding flax plants in the wild doesn’t pose a significant risk of confusing them with similar-looking poisonous plants, it is always advisable that you familiarize yourself with the relevant plant profiles before harvesting.
Flaxseed should be stored in a dry and dark place. Ground flaxseed, in particular, does not keep long; it should be consumed within half a year. Ground flaxseed from the supermarket is often packaged with a protective gas and vacuum-sealed. It is best to remove the seeds from their plastic packaging and store in a dark, airtight container. If possible, buy whole flaxseed and grind it freshly at home as you need it. Whole dried flaxseed can be kept for up to one year. You can tell whether the seeds are still fresh from their taste: they should taste nutty and not bitter or rancid. Given the high humidity of the air, it’s best not to store flaxseed in the refrigerator.
Just 100 g of flaxseed contains 23 g omega-3 fatty acids (alpha-linoleic acid or ALA), which is equivalent to 1141 % of a woman’s recommended daily intake (RDI) (based on a diet of 2000 calories per day). 10 g of flaxseed is therefore a sufficient daily intake. Flaxseed has the highest content of this essential fatty acid, followed by chia seeds (892 % of RDI), walnuts (454 % RDI), and unshelled hemp seeds (434 %).5,6
Flaxseed is rich in fiber (hemicellulose, cellulose, and lignin), with 27 g per 100 g. This accounts for more than 100 % of a person’s recommended daily intake. Flaxseed is also a very rich source of lignans, a type of phytoestrogen (natural hormone).5
Does flaxseed contain prussic acid? Flaxseed naturally produces cyanogenic glycosides. It also contains the enzyme beta-glucosidase, which when consumed releases cyanide (the salt of prussic acid). Despite a high content of cyanide, consuming flaxseed is harmless to health as long as you follow the standard recommendation of maximum 15 g flaxseed per meal (about 2 tablespoons).2
Oilseeds like flaxseed can absorb considerable amounts of cadmium from the soil; it is not uncommon for flaxseed to contain more than 1 mg/kg of cadmium. The German Federal Institute for Risk Assessment therefore recommends that you should not eat more than 20 g flaxseed per day.1
Flaxseed is abundant and many micronutrients and 10 g of flaxseed contains the following recommended daily intake of each nutrient: magnesium 10.5 %, manganese 12.4 %, copper 12.2 %, tryptophan 12 %, and thiamine (vitamin B1) 14.9%. An extensive overview of flaxseed’s nutritional value can be found in the tables below.6
Given its nutrient density and health-promoting properties, US-grown flaxseed could almost be described as a domestic “superfood.” However, the term superfood is overridingly used for marketing and does not guarantee that a food is particularly healthy.
Omega-3 fatty acids are the precursors for the synthesis of bioactive lipids and neurotransmitters.5 A healthy ratio of omega-6 fatty acids (linoleic acid) to omega-3 fatty acids is 5:1 or less; however, flaxseed has an almost inverse ratio of 1:4. This means that flaxseed is an excellent source of omega-3 fatty acids. When combined with a low intake of omega-6 fatty acids, a healthy body can use omega-3s to produce eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both of which have anti-inflammatory effects.7 With a ratio of 1:3, chia seeds are the only food that come close to this value. Otherwise, practically everything has more inflammation-promoting omega-6 fatty acids than omega-3 — the higher number comes first before the colon. However, chia seeds should be eaten in moderation (less than 15 g/day) as they dilute the blood.
The water-soluble dietary fiber in flaxseed has strong mucous and gel-forming capacities, creating better passage through the gastrointestinal tract. Studies have shown that whole or coarsely ground flaxseed is better than finely ground flaxseed for this purpose. An increased fluid intake is essential for flaxseed to have positive effects on the gut, given that flaxseed expands when it comes into contact with liquid.5
Numerous studies indicate that lignans can help to prevent hormone-dependent cancers such as breast and prostate cancer. However, it is still unclear how high the concentration of lignans has to be to have preventative effects, and whether phytoestrogens contained in flaxseed may even have the opposite effect of increasing the risk of cancer. The positive effects of lignans indicated by studies are potentially the result of a combination of lignans and omega-3 fatty acids.5
Flaxseed has laxative, expectorant, and pain-relieving effects and may relieve irritated tissue.10 The mucilage contained in flaxseed has a positive effect on all inflammatory processes in the gastrointestinal tract, as well as helping to treat respiratory diseases.3
Flaxseed may interfere with the intestinal absorption of medicine. You should therefore allow at least two to three hours between consuming flaxseed and taking medication.8
While flaxseed oil may increase the risk of premature birth, consuming whole or ground flaxseed in the dosage that we recommended above does not pose a risk for pregnant women. As flaxseed expands upon digestion and makes you feel fuller, it may help to regulate a sluggish bowel. In case of constipation during pregnancy, consult a specialist.8,9
While small quantities of prussic acid can improve breathing and digestion, taking a high dose may cause acute poisoning by blocking energy production. The most severe cases of overdose may lead to respiratory failure and even death. However, the recommended maximum daily dose of flaxseed does not pose any health risk.2,4
What are the medicinal benefits of flaxseed? Flaxseed can regulate your digestion thanks to its swelling and mucilage capacities. Flaxseed expands the contents of the intestine and causes a stretch stimulus that helps with digestive contractions (peristalsis). Overall, flaxseed increases digestive activity and can help with chronic constipation.4
In case of diverticulitis (inflamed diverticula pouches in the large intestine), flaxseed should be finely ground and mixed with cereal flakes and plenty of liquid. Flaxseed mucous protects gastrointestinal mucous membranes and can relieve gastris, pharyngitis, chronic bronchitis, coughs, and sore throats. Flaxseed is a suitable dietary supplement for menstrual cramps, arteriosclerosis, and eczema, and flaxseed oil may be useful in treating rheumatoid arthritis.4
Flaxseed can also be used as a poultice. For external application, soak freshly ground flaxseed in cold water and mix to create a smooth paste. Bring the paste to the boil, stirring constantly. While the mixture is as hot as possible, spread the paste evenly over the injured area and cover with a light cloth. For best results, insulate the poultice by wrapping it in a woollen cloth.10
Flaxseed poultices can be used to treat stitches, colic, muscle pain, bruises,4 bronchitis, pleurisy, sore throats, burns, boils, and ulcers. The paste can be mixed with white mustard (sinapis alba) to relieve chest pain. It can also be mixed with honey and lemon to create a cough medicine.4
The first mentions of flaxseed in writing appear around 500 B.C., when Hippocrates wrote about flaxseed being used to relieve abdominal pain, and treat diarrhea and catarrh. Paracelsus also mentions flaxseed mucilage being used as a soothing cough medicine.10 In eighth century France, Emperor Charlemagne introduced laws requiring his people to consume flaxseed for general public health.4
Common flaxseed (Linum usitatissimum) originates from linum bienne, a biennial wild flax plant native to the Mediterranean region. This species was cultivated in Mesopotamia from 7500 BCE. According to Wikipedia, common flax probably originated in Mesopotamia or Egypt.11 Flaxseed grows in temperate and subtropical regions of both hemispheres.12
There are two easily distinguishable types of common flax: the tall, sparsely branched flax “web” with only a few flowers, which is used to produce linen, and the smaller, strongly blooming, fruit-bearing oilseed flax, which is cultivated for oil production and forage.4
The type of flax that you plant in your garden depends on how you wish to use it. Flax plants generally grow better in warmer temperatures and are sensitive to frost. Ideally, plant them in a protected location with dry, permeable, low-nitrogen soil. The seeds should be sown between the end of March and the beginning of April, depending on the weather. They should be planted in an area where no flaxseed has been grown for at least four years; otherwise, fungus from flax debris risks forming in the soil and causing the seedlings to rot. Flax is a “long-day plant,” needing lots of light and growing particularly fast in May and June. Oilseed flax only needs a small amount of water and does not require fertilizer. The plants can be harvested after 110 to 120 days, ideally one week before the seeds are fully ripe. Harvest by pulling up handfuls of flax stalks by their roots.13
When cultivating flax, it is important that the previous crops grown in the area of cultivation leave little weed. For this reason, oats are considered the best crop to grow before flax. In France and Belgium, flax is often cultivated after maize. Low plant density encourages seed formation, while high plant density encourages the formation of flax fiber.
The main cultivation area for flax is North America and Canada. Between 1996 and 2005, the annual harvest fluctuated considerably between 517,000 and 1,082,000 tons of flaxseed. According to the United Nations Food and Agriculture Organization, the 2006 global harvest was 2,569,793 tons.11
Flax plants produce many flowers; however, these flowers contain little pollen and nectar, and as such flax plants are not an ideal source of nectar.14
Flaxseed (Linum) or flax is a plant genus that is a member of the flax plant family (Linaceae), which contains around 200 species. Flaxseed is the name given to the seeds of common flax (Linum usitatissimum).15
Flaxseed may be referred to as linseed, common flax, cultivated flax, or oilseed flax.