Flaxseed oil as a dietary supplement
Flaxseed oil, derived from the seeds of the flax plant, is often considered a dietary supplement for its potential health benefits, particularly as an alternative to fish oil. It is rich in omega-3 fatty acids, specifically alpha-linolenic acid (ALA), which is essential for the body. However, the type of omega-3s present in flaxseed oil differs from those found in fish oil, leading to different effects and benefits. Flaxseed oil does not contain lignans, which are compounds present in whole flaxseeds that are being researched for cancer prevention.
Typically consumed in doses of 1 to 2 tablespoons daily, flaxseed oil can be added to salads or taken in capsule form. While it is touted for various potential health benefits, including heart disease prevention and support for autoimmune conditions like Sjögren's syndrome, the evidence is often inconsistent or inconclusive. Some studies suggest it may help with cholesterol levels, while others indicate no significant effects. Safety-wise, flaxseed oil is generally safe when used appropriately, but individuals with certain health conditions, such as cancer risks or low blood pressure, should consult a healthcare professional before use. Overall, flaxseed oil may serve as a nutritional supplement to enhance essential fatty acid intake, but further research is needed to fully understand its therapeutic efficacy.
Flaxseed oil as a dietary supplement
- DEFINITION: Plant product consumed for specific health benefits.
- PRINCIPAL PROPOSED USES: None
- OTHER PROPOSED USES: Bipolar disorder, cancer prevention, heart disease prevention, high blood pressure, high cholesterol, pregnancy support, rheumatoid arthritis, Sjögren’s syndrome
Overview
Flaxseed oil, which is derived from the hard, tiny seeds of the flax plant, has been proposed as a less smelly alternative to fish oil. Like fish oil, flaxseed oil contains omega-3 fatty acids, a type of fat the body needs as much as it needs vitamins.
However, it is important to realize that the omega-3 fatty acids in flaxseed oil are not identical to those in fish oil. Flaxseed oil contains alpha-linolenic acid (ALA), while fish oil contains eicosapentaenoic acid and docosahexaenoic acid. The effects and potential benefits may not be the same.
Whole flaxseed contains another important group of chemicals known as lignans. Lignans are being studied for use in preventing cancer. However, flaxseed oil contains no lignans.
Requirements and Sources
Flaxseed oil contains both omega-3 and omega-6 fatty acids, which are essential to health. Although the exact daily requirement of these essential fatty acids is not known, deficiencies are believed to be fairly common. Flaxseed oil may be an economical way to ensure that one gets enough essential fatty acids in the diet.
The essential fatty acids in flax can be damaged by exposure to heat, light, and oxygen (essentially, they become rancid). For this reason, one should not cook with flaxseed oil. A good product should be sold in an opaque container, and the manufacturing process should keep the temperature under 100° Fahrenheit. Some manufacturers combine the product with vitamin E because it helps prevent rancidity.
Therapeutic Dosages
A typical dosage is 1 to 2 tablespoons of flaxseed oil daily. It can be taken in capsule form or made into salad dressing. Some people find the taste pleasant, although others would disagree. For whole flaxseed, a typical dose is 1 tablespoon of the seed (not ground) with plenty of liquid two to three times daily.
Therapeutic Uses
The best use of flaxseed oil is as a general nutritional supplement to provide essential fatty acids. There is little evidence that it is effective for any specific therapeutic purpose.
Flaxseed oil has been proposed as a less smelly alternative to fish oil for the prevention of heart disease. However, there is no consistent evidence that it works. One double-blind study of fifty-six people failed to find that flax oil improved cholesterol profile. Other studies did find improvements in cholesterol or blood pressure (or both), but these were small trials, and they had serious problems in study design.
One study found that a diet high in ALA (from sources other than flaxseed oil) was associated with a reduced risk of heart disease. However, there were so many other factors involved that it is hard to say what caused what.
Sjögren’s syndrome is an autoimmune condition in which the immune system destroys moisture-producing glands, such as tear glands and salivary glands. It can occur by itself or with other autoimmune diseases, such as lupus. One small double-blind study found preliminary evidence that the use of flaxseed oil at a dose of 1 to 2 grams daily can improve dry eye symptoms in Sjögren’s syndrome.
One preliminary study hints that flaxseed oil may enhance the effects of conventional treatments for bipolar disorder when combined with conventional medications. It has been suggested that flaxseed oil may have anticancer effects because of its ALA and lignan content. However, the supporting evidence for this belief is incomplete and somewhat contradictory (some studies actually found weak evidence of increased cancer risk with higher ALA intake). Although fish oil appears to be effective in reducing symptoms of rheumatoid arthritis, one study failed to find flaxseed oil helpful for this purpose. Another study failed to find flaxseed oil helpful for preventing premature birth. One small, randomized trial found flaxseed oil ineffective for reducing blood sugar in people with type 2 diabetes.
Study continued on flaxseed and flaxseed oil as the twenty-first century progressed. According to a review by the National Center for Complementary and Integrative Health, flaxseed and flaxseed oil do show great potential for providing health benefits. A 2019 study found flaxseed to be helpful to people with heart and blood vessel disease. Other studies suggested benefits for type 2 diabetes, reducing inflammation, and regulating the gut biome. Studies showed conflicting evidence on how flaxseed and flaxseed oil affect the symptoms of menopause. Finally, a topical application of flaxseed was shown to have possible benefits for people with carpal tunnel syndrome.
Safety Issues
Flaxseed oil appears to be a safe nutritional supplement when used as recommended. However, because of the contradictory evidence regarding its effects on cancer, persons at high risk of cancer should not take flaxseed oil except on the advice of a physician. People with low blood pressure and bleeding disorders should also avoid flaxseed oil, as well as women who are breastfeeding or pregnant, as it affects hormones.
Bibliography
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“The Benefits of Flaxseed Oil.” Cleveland Clinic Health Essentials, 4 May 2022, health.clevelandclinic.org/flaxseed-oil-benefits. Accessed 23 Nov. 2024.
“Flaxseed and Flaxseed Oil.” National Center for Complementary and Integrative Health, Dec. 2020, www.nccih.nih.gov/health/flaxseed-and-flaxseed-oil. Accessed 23 Nov. 2024.
Maillard, V., et al. "N-3 and N-6 Fatty Acids in Breast Adipose Tissue and Relative Risk of Breast Cancer in a Case-Control Study in Tours, France." International Journal of Cancer, vol. 98, 2002, pp. 78-83.
Neukam, et al. "Supplementation of Flaxseed Oil Diminishes Skin Sensitivity and Improves Skin Barrier Function and Condition." Skin Pharmacology and Physiology, vol. 24, 2010, pp. 67-74.
Nunn, Megan. “What Is Flaxseed Oil?” Verywell Health, 19 Sept. 2023, www.verywellhealth.com/flaxseed-oil-health-benefits-how-to-use-and-cautions-4178046. Accessed 23 Nov. 2024.
Paschos, G. K., et al. "Dietary Supplementation with Flaxseed Oil Lowers Blood Pressure in Dyslipidaemic Patients." European Journal of Clinical Nutrition, vol. 61, 2007, pp. 1201-1206.
Silver, Natalie. “Flaxseed Oil Side Effects.” Healthline, 18 Sept. 2018, www.healthline.com/health/flaxseed-oil-side-effects. Accessed 23 Sept. 2024.