Flaxseed oil is made from the seeds of the flax plant (Linum usitatissimum). Flaxseed oil is used in manufacturing to make paints, varnishes, linoleum and soap. The oil is used as cooking oil and to make margarine and may be applied to the skin to smooth roughness. Flaxseed oil is also used as a dietary supplement.
Why flaxseed oil is used
Flaxseed oil contains omega-3 and omega-6 fatty acids, which are both polyunsaturated fats. Both are necessary as part of a balanced diet. Omega-3 fatty acids often come from fish oil which contains an acid known as DHA. This type of omega-3 fatty acid is known to reduce inflammation and can help fight heart disease and arthritis.
Flaxseed oil contains alpha-linolenic acid (ALA). Although the body has a limited ability to convert ALA to the more beneficial DHA, studies are not conclusive that flaxseed oil has the same benefits as fish oil.
In general, no significant benefits from flaxseed oil have been proven. Flaxseed oil is used for these conditions:
• Cholesterol - Flaxseed oil is sometimes used to lower cholesterol. At least one study showed no benefit in taking flaxseed oil to lower cholesterol.
• Heart disease – Some studies show that a diet rich in ALA (which is found in flaxseed oil) can lower the risk of suffering a fatal heart attack. ALA may help lower inflammation in blood vessels, lower the risk of irregular heartbeats, and make portions of the blood less likely to form clumps that can block blood vessels.
• Blood pressure – Some studies show omega-3 fatty acids can lower blood pressure, but it has not been proven that flaxseed oil provides this benefit.
How flaxseed oil is used
Flaxseed oil is available as liquid oil and in softgel capsules. The oil needs to be refrigerated to prevent it from going bad. The oil can also be damaged by heat and light and is generally sold in dark or non-transparent containers. High quality flaxseed oil should be made using freshly pressed seeds and should be processed and bottled away from light, extreme heat, and oxygen. Lower quality flaxseed oil may contain heavy metals such as mercury and lead. Check the label to avoid these products.
Cautions for flaxseed oil
Flaxseed oil is generally safe in foods. Flaxseed oil supplements may interact with some medications. Cautions for flaxseed oil include:
• Blood thinners – Flaxseed oil may act as a blood thinner. So if you are taking blood thinning medications or drugs that prevent clotting, do not use flaxseed oil or your blood may become too thin.
• Blood sugar medications – Flaxseed oil contains omega-3 fatty acids which are known to increase blood sugar. Using this supplement may mean you will need more medication to lower blood sugar.
• Diarrhea – Large doses of flaxseed oil (30 grams or more per day) can cause diarrhea which can lead to dehydration.
• Prostate cancer – Some studies suggest flaxseed oil may increase a man’s chance of getting prostate cancer. Researchers are still studying this and have not come to a definite conclusion whether flaxseed oil is connected to prostate cancer.
• Pregnancy – Some studies suggest flaxseed oil may cause the baby to be born early. Do not take flaxseed oil if you are pregnant or breastfeeding.
• Blood pressure – Flaxseed oil may lower blood pressure. Be careful with flaxseed supplements if you are taking medication to lower your blood pressure.
Be sure to talk to your health care provider about all supplements you choose to take, including flaxseed oil.
Sources:
University of Maryland Medical Center
National Center for Complementary and Alternative Medicine
National Institutes of Health: Medline Plus