What Is Flaxseed Oil?
Flaxseed oil is made from flaxseed .
For many centuries, people used flaxseed for its laxative properties. It is also used in bakery products and to make linen .
Flaxseed oil contains many active compounds :
- Omega-3 fatty acids (alpha-linolenic acids)
- Proteins help decrease heart disease risk factors
- Fibers help prevent constipation
- Phenolic compounds (lignans) help protect against cancer
- Minerals (calcium, magnesium, and phosphorus)
The alpha-linolenic acid (ALA) from flaxseed oil is converted in the body into the unsaturated fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) .
These unsaturated fatty acids are then converted to lipids (fats). The fat molecules promote eye health as well as brain and nervous system development. They also reduce the risk of high blood pressure, high cholesterol, and cancer, improve memory, and slow aging and risk of coronary disease .
Eating flaxseed in both ground and oil forms increases blood ALA. However, consuming flaxseed oil rather than ground flaxseed results in significantly higher ALA levels in the blood .
Health Benefits of Flaxseed Oil
1) Flaxseed Oil Protects the Heart
The alpha-linolenic acid (ALA) in flaxseed oil is converted to EPA and DHA in the body .
In a study (DB-RCT) of 56 participants, a 3-gram daily supplementation of ALA (from flaxseed oil supplements) increased blood EPA levels. These levels grew 60% after 12 weeks in comparison to the placebo group, which showed no EPA increase .
2) Flaxseed Oil Lowers Cholesterol Levels
In a study (DB-RCT) of 55 patients with high cholesterol, flaxseed extract supplementation reduced total cholesterol and LDL (bad) cholesterol after 8 weeks .
12 months of high flaxseed diets also lowered LDL and total cholesterol in heart disease patients .
Additionally, the type of food that contains flaxseed may influence its effects on cholesterol. Flaxseed drink was more effective than flaxseed bread in lowering total and LDL cholesterol in a study (DB-RCT) of 17 subjects .
However, in hamsters, flaxseed, but not flaxseed oil, prevented cholesterol increases .
3) Flaxseed Oil Benefits Skin Health
Low ALA is associated with dry and uncomfortable skin and poor skin quality .
Flaxseed oil has a high ALA content, which supports skin health. Flaxseed decreases skin cell inflammation and promoted regenerative functions .
Eczema is a common skin disorder with dry, uncomfortable, and red skin. Flaxseed oil lowered saturated fatty acid levels in both horses and human skin cells, which may reduce rash areas and help clear irregular skin [17, 16].
In a study (DB-RT) of 13 women, flaxseed oil supplementation improved skin sensitivity, hydration, and overall condition .
In another study (DB-RCT) of 45 women, flaxseed oil ingestion for 12 weeks reduced skin redness and roughness .
Flaxseed also lowered skin cell inflammation and increased repair in skin cells .
4) Flaxseed Oil Is Anti-Cancer
Both flaxseed and flaxseed oil contain linoorbitides, a family of compounds that have possible cancer-fighting and antioxidant activities. This compound family increases the shelf life stability of flaxseed oil in storage. It likely does the same within the human body, providing strong antioxidant properties that lower the rate of tumor cell growth .
A review showed that flaxseed supplementation reduced tumor growth in 32 breast cancer patients. Additionally, flaxseed lignans reduced breast cancer risk .
Though flaxseed oil contains a compound that prevents cancer, the quantity and frequency necessary to achieve the desired blood concentration may not make it a useful therapy in cancer treatment .
5) Flaxseed Protects Against Diabetes
Flaxseed may also play a role in lowering risk and managing diabetes.
Daily flaxseed consumption also improved glucose control in obese individuals with prediabetes in a study (randomized, cross-over) of 25 participants .
Individuals with PCOS might have a higher risk for diabetes and high insulin and glucose levels. In a study (DB-RCT) of 60 women with PCOS, flaxseed oil supplementation lowered their insulin levels .
Flaxseed lignans reduced diabetes incidence in rats .
In diabetic rats, daily flaxseed oil consumption prevented diabetes-related brain dysfunction. Flaxseed oil stopped oxidative stress and improved neurotransmitter levels, thus protecting brain cells .
However, in a study (DB-RCT) of 90 prediabetic individuals, flaxseed powder had no effect on their glucose levels or insulin resistance .
6) Flaxseed Oil May Help with Weight Loss
The increase in leptin production helped support fat loss and reduced fat buildup in rabbits’ arteries .
7) Flaxseed Oil Improves Gut Health
In a study (DB-RCT) of 50 patients, daily supplementation with 4 mL of flaxseed oil helped relieve constipation .
8) Flaxseed Oil Reduces Inflammation
In a study (DB-RCT) of 100 patients with carpal tunnel syndrome, the patients reported an improvement in their symptoms after topical flaxseed oil application. They had reduced inflammation and pain after a month of oil application .
In rats, flaxseed oil injections under the skin helped reduce inflammation by preventing the widening of blood vessels. It also decreased inflammatory markers (histamine, bradykinin, prostaglandin E2, and leukotriene B4) .
9) Flaxseed Oil Protects the Brain
In a study (DB-RCT) of 51 bipolar disorder patients, flaxseed oil supplementation helped improve their mood .
Daily flaxseed oil consumption helped prevent diabetes-related brain dysfunction in diabetic rats. Flaxseed oil stopped oxidative stress, thus protecting brain cells .
In rats, pretreatment with flaxseed oil protected against seizures. It helped reduce convulsion time .
10) Flaxseed Oil May Improve ADHD Symptoms
In a pilot study of 30 children with ADHD, supplementation with flaxseed oil and vitamin C improved their ADHD symptoms and increased their EPA and DHA levels. The children had improved restlessness, inattention, self-control, and impulsiveness .
11) Flaxseed Oil May Protect the Kidneys
In a rat model of kidney dysfunction, both flaxseed oil and ground flaxseed supplementation helped prevent the decline in kidney function. However, the ground flaxseed was more effective at protecting against kidney injuries than the oil .
Flaxseed oil diets also helped reduce polycystic kidney damage in male and female rats, although it was more effective in female rats. A combination of flax oil and one of its antioxidants (SDG) prevented excess protein in their urine, cystic change, and inflammation in both genders. However, the females also had less oxidative damage .
Additionally, high blood pressure can damage the kidneys. In rats with high blood pressure, flaxseed oil-supplemented diets helped lower blood pressure and markers of kidney damage (creatinine, blood urea nitrogen, renin, and uric acid) .
12) Flaxseed Oil May Improve Bone Health
Increasing ALA dietary intake by taking flaxseed oil supplements can protect against bone breakdown .
13) Flaxseed Oil Improves Menopausal Symptoms
In a study of 140 menopausal women, flaxseed oil supplementation improved their menopause symptoms. The women reported less hot flashes and an increase in quality of life .
14) Flaxseed Oil Helps Reduce Sjogren’s Syndrome Symptoms
Sjogren’s syndrome is an immune system disorder with the uncomfortable symptoms of dry eyes and a dry mouth.
Taking daily 1 or 2 g flaxseed oil supplements significantly reduced eye inflammation and helped with dry eye symptoms in a study (RCT) of 38 Sjogren’s syndrome patients. Flaxseed greatly increased eye comfort and health .
Supplementing with Flaxseed Oil
Limitations and Caveats
Although many animal studies have been performed, there are limited human studies of flaxseed oil. Thus, it is recommended that you consult with a doctor before taking flaxseed oil supplements for their health benefits.
Do not take flaxseed oil if it is rancid or expired, as it can potentially become toxic.
Flaxseed oil can be taken orally to meet the recommended daily omega-6 to omega-3 ratio of 5:1. The recommended daily amount of alpha-linolenic acid from the diet/supplementation is 1.1–2.2 grams per day [58, 59].
However, people with specific health conditions may be recommended by a medical professional to take larger amounts. If you have a specific health concern or disorder, ask your doctor before taking flaxseed oil [58, 59].
Side Effects and Interactions
Higher omega-3 fatty acids levels are associated with a slightly longer bleeding time and slower clotting time. However, there are no cases of bleeding problems documented, even at high levels of omega-3 and when taken with blood thinning medications .
When first taking flaxseed oil, some adults who took more than 6 grams per day had some stomach and intestinal issues. This side effect only lasted for the first few weeks of consumption .
Additionally, people who are allergic to flaxseed should not take flaxseed oil .
Although flaxseed contains cyanogenic glycosides, proper preparation and processing of flaxseed products will reduce the risk of poisoning .
Flaxseed Oil Sources
Flaxseed Oil vs. Fish Oil
Both flaxseed oil and fish oil are rich sources of omega-3 fatty acids. Fish oil has EPA and DHA directly to the blood and body. Flaxseed oil has ALA, which is then changed into EPA and DHA within the body [63, 64].
However, for vegetarian or vegan people, flaxseed oil is a way to meet omega-3 daily needs and receive the positive effects of omega-3 fatty acids and lignans.
In a study (DB-RCT) of 60 diabetic patients with heart disease, 12 weeks of flaxseed oil supplementation improved the production of genes related to insulin, inflammation, and fat. It increased PPAR-α levels, which helps with insulin and fat metabolism and maintains fat and glucose balance .
Meanwhile, it reduced inflammation and heart disease risk by decreasing the gene production levels of :
In diabetic rats, a diet high in flaxseed oil significantly increased PPAR-α levels. This helps maintain carbohydrate and fat balances. On the other hand, it reduced SREBP-1, which reduces the rats’ fat levels .
In diabetic rats, flaxseed oil also decreased the production of the following inflammatory genes :
After using flaxseed oil, users reported an improvement in their heart and brain health. It also helped with pain and PMS symptoms. They also praised it as a good, vegetarian-friendly alternative to fish oil.
However, some people report that flaxseed oil gave them diarrhea and did not help with joint pain.