Gamma-linolenic acid (GLA) is an omega-6 polyunsaturated fatty acid, chemically designated as 18:3 (n-6), meaning it has 18 carbon atoms and three cis double bonds located at the 6th, 9th, and 12th positions from the methyl end of the molecule. Its molecular formula is C18H30O2, and it is primarily found in seed oils such as evening primrose oil, borage oil, and black currant seed oil. GLA is essential for human health, contributing to brain function, normal growth and development, and the regulation of metabolism and reproductive systems. It is converted in the body to dihomo-gamma-linolenic acid (DGLA), which has anti-inflammatory properties. The chemical structure of GLA is characterized by a carboxylic acid group (-COOH) at one end and a long hydrocarbon chain with three double bonds, making it a crucial component in various physiological processes.
Food Sources Gamma-Linolenic Acid
It is an omega-6 fatty acid known for its anti-inflammatory properties and potential health benefits. It is found in various plant-based oils and some other food sources. Below is a detailed overview of the primary food sources of GLA.
1. Borage Oil
Borage oil is one of the richest sources of GLA, containing approximately 18-26% GLA. It is derived from the seeds of the borage plant (Borago officinalis) and is commonly used in supplements rather than as a direct food source due to its high concentration of GLA.
2. Evening Primrose Oil
Evening primrose oil, extracted from the seeds of the evening primrose plant (Oenothera biennis), is another significant source of GLA, containing about 9% GLA. It is often used in supplements to address various health issues, including premenstrual syndrome (PMS) and skin conditions.
3. Black Currant Seed Oil
Black currant seed oil contains around 15-20% GLA. It is derived from the seeds of the black currant plant (Ribes nigrum) and is used both as a dietary supplement and in some cosmetic products.
4. Hemp Oil
Hemp oil, obtained from the seeds of the hemp plant (Cannabis sativa), contains about 0.5-6% GLA. The GLA content can vary depending on the growing conditions of the hemp. Unlike some other GLA sources, hemp oil is commonly used as a food ingredient, particularly in dressings and smoothies.
5. Spirulina
Spirulina, a type of blue-green algae, contains trace amounts of GLA. It is typically consumed as a supplement or added to foods in powdered form. Spirulina is known for its high nutrient content and health benefits.
6. Human Milk
GLA is naturally present in human milk, providing an essential source of this fatty acid for infants. This highlights the importance of breastfeeding for early development.
7. Green Leafy Vegetables and Nuts
These contain trace amounts of GLA, though not in significant quantities compared to the oils mentioned above.
8. Oats and Barley
These grains also contain small amounts of GLA.
Uses of Gamma-Linolenic Acid
1. Anti-Inflammatory Effects
Gamma-linolenic acid (GLA) is renowned for its potent anti-inflammatory properties. This omega-6 fatty acid is converted in the body to dihomo-gamma-linolenic acid (DGLA), which subsequently produces anti-inflammatory eicosanoids. These compounds play a crucial role in modulating inflammatory responses, making GLA a valuable nutrient for managing chronic inflammatory diseases such as arthritis, diabetes, and cardiovascular diseases. Research indicates that GLA supplementation can reduce the production of pro-inflammatory cytokines and eicosanoids, thereby mitigating inflammation and its associated symptoms.
2. Skin Health
GLA is highly beneficial for maintaining healthy skin. It helps in the synthesis of prostaglandins, which are lipid compounds that perform various physiological functions, including the regulation of skin barrier function. Studies have shown that GLA can significantly improve skin hydration, reduce transepidermal water loss (TEWL), and alleviate conditions such as eczema and dermatitis. The topical application of GLA-rich oils like borage oil has been found to be particularly effective in treating dry skin and inflammatory skin disorders.
3. Rheumatoid Arthritis
Rheumatoid arthritis (RA) is a chronic inflammatory disorder that primarily affects the joints. GLA has been studied extensively for its potential to alleviate the symptoms of RA. Clinical trials have demonstrated that GLA can reduce joint pain, swelling, and stiffness in RA patients. The anti-inflammatory effects of GLA are attributed to its ability to inhibit the production of inflammatory mediators. Patients receiving GLA supplements have shown significant improvements in disease activity compared to those on placebo.
4. Diabetic Neuropathy
Diabetic neuropathy is a common complication of diabetes, characterized by nerve damage and pain. GLA has shown promise in managing this condition. Studies suggest that GLA supplementation can reduce symptoms such as pain, numbness, and tingling in diabetic patients. The efficacy of GLA is particularly pronounced in individuals with well-controlled blood sugar levels. The anti-inflammatory properties of GLA, along with its role in nerve function, make it a valuable therapeutic option for diabetic neuropathy.
5. Premenstrual Syndrome (PMS)
Premenstrual syndrome (PMS) encompasses a range of physical and emotional symptoms that occur before menstruation. GLA has been found to be effective in alleviating PMS symptoms, including breast tenderness, mood swings, and bloating. The mechanism behind this benefit is thought to involve the regulation of prostaglandin production, which can influence hormonal balance and reduce inflammation. Women taking GLA supplements have reported significant relief from PMS symptoms.
6. Cardiovascular Health
Some studies suggest that GLA can lower blood pressure and reduce the risk of heart disease. The anti-inflammatory effects of GLA help in preventing the development of atherosclerosis, a condition characterized by the buildup of plaque in the arteries. Additionally, GLA may improve endothelial function and reduce the levels of harmful cholesterol, thereby promoting overall cardiovascular health.
7. Cancer
Research into the role of GLA in cancer treatment is ongoing, with some promising findings. GLA has been shown to enhance the efficacy of certain cancer treatments, such as tamoxifen in breast cancer patients. The anti-inflammatory and anti-proliferative properties of GLA may help in inhibiting the growth and spread of cancer cells. However, more extensive clinical trials are needed to fully understand the potential of GLA in cancer therapy.
8. Bone Health
GLA plays a role in maintaining bone health by regulating the production of prostaglandins, which are involved in bone metabolism. Some studies suggest that GLA supplementation can improve bone density and reduce the risk of osteoporosis, particularly in postmenopausal women. The anti-inflammatory properties of GLA may also help in reducing bone resorption, thereby supporting overall bone health.
9. Weight Management
Some research indicates that GLA can help in reducing body fat and improving body composition. The mechanism behind this effect involves the regulation of lipid metabolism and the reduction of inflammatory markers associated with obesity. However, more research is needed to establish the efficacy of GLA in weight management.
10. Asthma
Asthma is a chronic respiratory condition characterized by inflammation and constriction of the airways. GLA has been studied for its potential to reduce asthma symptoms due to its anti-inflammatory properties. Some studies suggest that GLA supplementation can improve lung function and reduce the frequency of asthma attacks. The anti-inflammatory effects of GLA may help in reducing airway inflammation and improving respiratory health.
11. Ulcerative Colitis
Ulcerative colitis is an inflammatory bowel disease that affects the colon and rectum. GLA has shown potential in managing this condition by reducing inflammation and promoting mucosal healing. Some studies suggest that GLA, in combination with other omega-3 fatty acids, can reduce the severity of symptoms and improve the quality of life in patients with ulcerative colitis. However, more research is needed to confirm these findings.
12. Attention Deficit-Hyperactivity Disorder (ADHD)
ADHD is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. Some studies have explored the role of GLA in managing ADHD symptoms, given its importance in brain function and development. While the evidence is mixed, some research suggests that GLA, in combination with other essential fatty acids, may help in reducing ADHD symptoms and improving cognitive function in children.
13. Menopausal Symptoms
Menopausal symptoms, such as hot flashes, mood swings, and vaginal dryness, can significantly impact the quality of life. GLA has been studied for its potential to alleviate these symptoms. The anti-inflammatory and hormonal regulatory effects of GLA may help in reducing the severity of menopausal symptoms. Some women have reported improvements in their symptoms with GLA supplementation, although more research is needed to confirm these benefits.
Gamma-Linolenic Acid Supplement
Here are the main available supplement forms of Gamma-Linolenic Acid (GLA):
1. Softgel capsules:
- Evening primrose oil capsules (typically 500-1000 mg)
- Borage oil capsules (usually 1000 mg with 240 mg GLA)
- Black currant seed oil capsules (500-1000 mg)
2. Liquid oils:
- Evening primrose oil
- Borage seed oil
- Black currant seed oil
3. Some specific Brands of GLA supplements include:
- NOW Supplements Borage Oil 1000 mg with 240mg GLA
- Life Extension Mega GLA with Sesame Lignans
- NaturalSlim Metaboil 500 with Evening Primrose Oil & GLA
- Uni Key Health GLA-90 with 180 mg GLA
Precautions and Who Should Avoid Gamma-linolenic acid
Gamma-linolenic acid (GLA) is an omega-6 fatty acid found in various plant seed oils, such as evening primrose oil, borage oil, and black currant seed oil. While it has several potential health benefits, certain individuals should avoid using GLA due to possible side effects and interactions with medications. Here are the key precautions and groups of people who should avoid GLA:
1. Pregnancy Women
There is insufficient reliable information about the safety of GLA during pregnancy. It may harm the fetus and potentially induce early labor. Therefore, pregnant women should avoid GLA supplements.
2. Breastfeeding
Similarly, there is not enough reliable information about the safety of GLA during breastfeeding. It is advised to avoid GLA supplements while breastfeeding.
3. Bleeding Disorders
GLA may slow blood clotting, increasing the risk of bruising and bleeding in individuals with bleeding disorders. People with such conditions should avoid GLA supplements.
4. Upcoming Surgery
Due to its potential to slow blood clotting, GLA should be discontinued at least two weeks before any scheduled surgery to minimize the risk of excessive bleeding during and after the procedure.
5. Seizure Disorders
There have been reports of seizures in individuals taking evening primrose oil (a source of GLA), especially in those with a history of seizure disorders or when taken in combination with anesthetics. Therefore, people with seizure disorders should avoid GLA supplements.
6. Certain Medications
Blood Thinners: GLA can interact with anticoagulant and antiplatelet drugs, such as warfarin (Coumadin) and clopidogrel (Plavix), increasing the risk of bleeding. Individuals on these medications should consult their healthcare provider before taking GLA.
Phenothiazines: People taking phenothiazines (e.g., chlorpromazine, fluphenazine) for schizophrenia should avoid GLA, as it may increase the risk of seizures.
7. High Triglycerides and Diabetes
High intake of omega-6 fatty acids, including GLA, can raise triglyceride levels and may increase the risk of high blood pressure in people with diabetes. Individuals with high triglycerides or diabetes should avoid GLA supplements.
8. Chronic Obstructive Pulmonary Disease (COPD)
Omega-6 fatty acids can exacerbate breathing difficulties in people with COPD. Therefore, individuals with COPD should avoid GLA supplements.
9. Allergies
Individuals who are allergic to GLA or any of its sources (e.g., evening primrose oil, borage oil) should avoid using GLA supplements.
Possible Drug Interactions with Gamma-Linolenic Acid
Blood Thinning Medications
GLA can slow blood clotting, which may increase the risk of bruising and bleeding, especially when taken with anticoagulant or antiplatelet drugs such as:
- Warfarin (Coumadin)
- Clopidogrel (Plavix)
- Aspirin
- Heparin
- Enoxaparin (Lovenox)
Ceftazidime
GLA may enhance the effectiveness of ceftazidime, an antibiotic in the cephalosporin class, against bacterial infections.
Chemotherapy Drugs
GLA may increase the efficacy of certain chemotherapy drugs, including:
- Doxorubicin
- Cisplatin
- Carboplatin
- Idarubicin
- Mitoxantrone
- Tamoxifen
- Vincristine
- Vinblastine
Cyclosporine
When taken with cyclosporine, an immunosuppressive drug used after organ transplants, GLA may increase the drug’s immunosuppressive effects and protect against kidney damage.
Phenothiazines
Individuals taking phenothiazines, a class of antipsychotic drugs including:
- Chlorpromazine (Thorazine)
- Fluphenazine (Stelazine)
- Perphenazine (Trilafon)
- Promethazine (Compazine)
- Thioridazine (Mellaril)
should avoid GLA as it may increase the risk of seizures.
Other Potential Interactions
- Amifampridine: GLA may increase the risk or severity of seizures.
- Amobarbital and Brexanolone: The therapeutic efficacy of these drugs may be decreased when used with GLA.
Safe Dosages of Gamma-Linolenic Acid
The safe dosage of GLA can vary depending on the source and the specific health condition being addressed. Here are some general guidelines:
- Adults: GLA is typically used in doses ranging from 320 mg to 480 mg per day for up to one year. Some sources suggest that doses up to 2.8 grams per day are possibly safe.
- Children: For conditions like atopic dermatitis, doses of 240 mg to 480 mg per day have been used.
Overdose of Gamma-Linolenic Acid
Taking GLA in excessively high doses can lead to more serious health issues:
- Inflammation: Doses greater than 3,000 mg per day may increase inflammation in the body.
- Bleeding: GLA can slow blood clotting, increasing the risk of bruising and bleeding, particularly in individuals with bleeding disorders or those taking anticoagulant medications.
- Seizures: High doses of borage oil (which contains GLA) have been associated with seizures in some cases.
How to choose Quality Supplements Gamma-Linolenic Acid
Here are some key tips for choosing high-quality gamma-linolenic acid (GLA) supplements:
1. Look for reputable brands: Choose supplements from well-established companies with a good reputation for quality and safety.
2. Check for third-party certifications: Look for seals from organizations like USP, NSF International, or ConsumerLab, which indicate the product has been independently tested for quality and purity.
3. Review the ingredient list: Make sure GLA is listed as a primary ingredient, typically sourced from borage oil, evening primrose oil, or black currant seed oil.
4. Check the GLA content: Look for products that clearly state the amount of GLA per serving. Effective doses typically range from 240-320 mg per day.
5. Avoid products with exaggerated claims: Be wary of supplements that promise miracle results or make drug-like claims.
6. Consider the form: GLA supplements are typically available as softgels or capsules. Choose the form that’s most convenient for you.
7. Check for freshness: Look for products with a clear expiration date and avoid those that smell rancid.
8. Research the company: Visit the manufacturer’s website to learn about their quality control processes and manufacturing standards.
9. Consult a healthcare professional: Discuss the use of GLA supplements with your doctor, especially if you have any health conditions or are taking medications.
10. Compare prices: While price alone doesn’t determine quality, extremely cheap products may be a red flag.
11. Read customer reviews: Look for feedback from other users, but be cautious of overly positive or negative reviews.
12. Check for allergens: If you have allergies, make sure the product is free from common allergens and manufactured in a facility that avoids cross-contamination.
Remember, the FDA does not strictly regulate dietary supplements, so it’s important to do your research and choose carefully. Quality GLA supplements should provide clear information about their source, potency, and manufacturing processes.
Combine Gamma-Linolenic Acid with Other Nutrients
Combining gamma-linolenic acid (GLA) with omega-3 fatty acids like EPA and DHA can enhance its anti-inflammatory properties and prevent potential pro-inflammatory effects by inhibiting the conversion of GLA-derived DGLA to arachidonic acid. This combination is particularly beneficial for reducing cytokine production and neutrophil recruitment in conditions like acute lung injury. Additionally, nutrients such as zinc, magnesium, vitamin C, vitamin B3, and vitamin B6 act as cofactors that support the optimal metabolism of GLA. Common supplement combinations include borage oil (rich in GLA) with fish oil (EPA/DHA), which have shown promise in improving skin health, managing inflammatory conditions, and providing cardiovascular benefits. However, consulting with a healthcare provider is recommended before starting any new supplement regimen.
FAQs about Gamma-Linolenic Acid
What is Gamma-Linolenic Acid?
Gamma-linolenic acid (GLA) is an omega-6 fatty acid found in various plant seed oils, such as evening primrose oil, borage oil, and black currant seed oil. It is essential for human health as the body cannot produce it on its own. GLA is involved in the production of anti-inflammatory and anticancer substances in the body.
What are the health benefits of GLA?
GLA has several potential health benefits, including:
- Reducing nerve pain in people with diabetic neuropathy.
- Alleviating symptoms of rheumatoid arthritis, such as pain and swelling.
- Improving skin conditions like dry skin and dermatitis by promoting hydration and reducing inflammation.
- Supporting hormonal balance, which can help with premenstrual syndrome (PMS) and menopausal symptoms.
- Potentially aiding in weight loss by providing essential fatty acids necessary for metabolism.
How do you take GLA?
GLA is commonly taken as a supplement in the form of capsules containing oils from evening primrose, borage, or black currant seeds. The typical dosage ranges from 320 to 480 mg per day, but it can vary depending on the condition being treated. It is advisable to consult with a healthcare provider to determine the appropriate dosage for your specific needs.
Are there any side effects of GLA?
GLA is generally considered safe when taken in doses up to 2.8 grams per day for up to one year. However, it can cause some side effects, including:
- Soft stools
- Diarrhea
- Belching
- Gas
GLA may also slow blood clotting, which can increase the risk of bruising and bleeding, particularly in individuals with bleeding disorders or those undergoing surgery.
Can GLA help with skin conditions?
Yes, GLA can help with various skin conditions. It is known to improve skin hydration, reduce transepidermal water loss (TEWL), and alleviate symptoms of dermatitis and eczema. GLA’s anti-inflammatory properties make it beneficial for maintaining healthy skin and reducing issues like dry skin, cracking, and redness.
Is GLA safe during pregnancy?
There is not enough reliable information to determine the safety of GLA during pregnancy. Therefore, it is recommended to avoid using GLA supplements while pregnant. However, GLA is generally considered safe for use while breastfeeding.
What foods are high in GLA?
GLA is primarily found in the oils of certain plants, including:
- Evening primrose oil
- Borage oil
- Black currant seed oil
These oils are the richest sources of GLA and are often used in supplements to provide therapeutic benefits.