Both flaxseed oil and linseed oil are extracted from seeds of the plant Linum usitatissimu. Flaxseed oil is pure and fit for human consumption; linseed oil goes through a refinement process and may contain additives that improve its paint-cleaning properties. Never drink linseed oil.

People often consume flaxseed meal for health purposes. This substance comes from the seeds of the Linum usitatissimum plant, an annual plant that likely originated in Egypt. Flaxseed also goes by the common name of linseed. Flaxseed meal and linseed meal are the same substance – the only difference is in the name.

DESCRIPTION
Linseed oil, also known as flaxseed oil or flax oil, is a colourless to yellowish oil obtained from the dried, ripened seeds of the flax plant (Linum usitatissimum). The oil is obtained by pressing, sometimes followed by solvent extraction. Linseed oil is a drying oil, meaning it can polymerize into a solid form. Owing to its polymer-forming properties, linseed oil can be used on its own or blended with combinations of other oils, resins or solvents as an impregnator, drying oil finish or varnish in wood finishing, as a pigment binder in oil paints, as a plasticizer and hardener in putty, and in the manufacture of linoleum. Linseed oil use has declined over the past several decades with increased availability of synthetic alkyd resins—which function similarly but resist yellowing.

Linseed oil is an edible oil in demand as a nutritional supplement, as a source of α-Linolenic acid, (an omega-3 fatty acid). In parts of Europe, it is traditionally eaten with potatoes and quark. It is regarded as a delicacy due to its hearty taste, that enhances the flavour of quark, which is otherwise bland.

COMPOSITION
Flax is rich in fat, protein and dietary fibre. An analysis of brown Canadian flax averaged 41% fat, 20% protein, 28% total dietary fibre, 7.7% moisture and 3.4% ash, which is the mineral-rich residue left after samples are burned. The composition of flax can vary with genetics, growing environment, seed processing and method of analysis.

BENEFITS
Flaxseed oil is high in omega-3 fatty acids and has been shown to have several health benefits, such as reduced blood pressure and improved regularity. What’s more, flaxseed oil can be used in a variety of ways. It can be used as a replacement for other types of oils, added to foods or applied to your skin and hair. Including just one or two servings of flaxseed oil in your daily routine is easy and could have numerous benefits for your overall health.

Evidence – Research on the use of flaxseed and flaxseed oil for specific conditions shows:

• Heart disease. Some studies suggest that alpha-linolenic acid, which is found in flaxseed and flaxseed oil, might benefit people with heart disease. Early research also suggests that flaxseed might help lower high blood pressure, which plays a role in heart disease.
• Cholesterol levels. Several studies show that taking flaxseed daily can reduce total cholesterol and low-density lipoprotein (LDL, or “bad”) cholesterol levels. However, other studies aren’t as favorable.
• Diabetes. Taking flaxseed might lower blood sugar levels in people with type 2 diabetes. However, the same results haven’t been found for flaxseed oil.
• Menopausal symptoms. Results have been mixed when it comes to use of flaxseed and the treatment of menopausal symptoms.

Generally safe – When taken in recommended amounts, flaxseed and flaxseed oil are generally safe to use. However, when taken in large amounts and with too little water, flaxseed can cause:

• Bloating
• Gas
• Diarrhea

Avoid use of flaxseed and flaxseed oil during pregnancy. Occasionally, using flaxseed or flaxseed oil causes an allergic reaction. Don’t eat raw or unripe flaxseeds. Because flaxseed oil might decrease blood clotting, stop using flaxseed oil two weeks before having elective surgery. The evidence is mixed as to whether flaxseed or flaxseed oil has any effect on the prostate or the risk of prostate cancer.

Interactions – Possible interactions include:

• Anticoagulant and anti-platelet drugs, herbs and supplements. These types of drugs, herbs and supplements reduce blood clotting. Flaxseed oil also might decrease blood clotting. It’s possible that taking flaxseed oil might increase the risk of bleeding.
• Blood pressure drugs, herbs and supplements. Flaxseed oil might lower blood pressure. Taking flaxseed oil with drugs, herbs and supplements that lower blood pressure might lower blood pressure too much.
• Diabetes drugs. Flaxseed might lower blood sugar levels. Taking flaxseed with diabetes drugs or herbs or supplements with hypoglycemic potential might lower blood sugar too much.
• Estrogens. Flaxseed might have an anti-estrogen effect. Taking flaxseed might decrease the effects of oral contraceptive drugs and estrogen replacement therapy.
• Oral drugs. Taking flaxseed might decrease absorption of oral drugs. Consider taking oral drugs and flaxseed an hour or two apart.

SOURCES :
https://www.mayoclinic.org/drugs-supplements-flaxseed-and-flaxseed-oil/art-20366457
https://www.tandfonline.com/doi/pdf/10.2478/V10133-010-0034-2
https://flaxcouncil.ca/wp-content/uploads/2015/03/FlxPrmr_4ed_Chpt1.pdf