GLA

What is GLA?

Gamma-linolenic acid (GLA) is an omega-6 polyunsaturated fatty acid with 18 carbon atoms and three double bonds. Unlike most omega-6 fatty acids found in the typical Western diet, GLA has unique anti-inflammatory properties. The human body can produce small amounts of GLA from linoleic acid through the enzyme delta-6-desaturase, but this conversion becomes less efficient with age, stress, and certain health conditions. GLA is primarily obtained through dietary supplements derived from plant oils, particularly evening primrose oil, borage oil, and black currant seed oil.

Health benefits & uses

Moderate evidence: GLA supplementation shows promise for reducing inflammation and supporting skin health. Clinical studies indicate potential benefits for atopic dermatitis, with some trials showing improvements in skin barrier function and reduced itching. Research also suggests GLA may help alleviate symptoms of rheumatoid arthritis when used as an adjunct therapy.

Limited evidence: Preliminary studies suggest GLA might support hormonal balance and reduce premenstrual syndrome symptoms, though results are inconsistent. Some research indicates potential cardiovascular benefits through improved lipid profiles, but more robust clinical trials are needed. Evidence for diabetic neuropathy relief exists but remains inconclusive.

How it works

GLA works by serving as a precursor to dihomo-gamma-linolenic acid (DGLA), which can be converted into beneficial prostaglandins, particularly prostaglandin E1 (PGE1). These prostaglandins have anti-inflammatory and vasodilatory effects, potentially explaining GLA’s therapeutic benefits. Unlike other omega-6 fatty acids that typically promote inflammation, GLA’s metabolic pathway produces compounds that can reduce inflammatory responses. This unique characteristic makes GLA distinct from the pro-inflammatory omega-6 fatty acids commonly consumed in Western diets.

Dosage

No official RDA (Recommended Dietary Allowance) or UL (Tolerable Upper Intake Level) has been established for GLA. Typical supplementation ranges from 240-2,800 mg daily, depending on the intended use and individual needs. For general wellness, doses of 240-500 mg daily are common. Higher therapeutic doses of 1,000-2,800 mg daily have been used in clinical studies for specific conditions like rheumatoid arthritis and atopic dermatitis. Healthcare providers should guide dosing decisions, especially for therapeutic applications or when combining with other supplements or medications.

Food sources

Natural food sources of GLA are extremely limited, making supplementation the primary method of obtaining meaningful amounts. Evening primrose oil contains approximately 8-10% GLA, while borage oil provides the highest concentration at 20-26% GLA. Black currant seed oil contains about 15-20% GLA. Spirulina, a blue-green algae, contains small amounts of GLA but would require large quantities to achieve therapeutic doses. Hemp seeds contain trace amounts, but again, insufficient for therapeutic purposes.

Safety & side effects

GLA supplements are generally well-tolerated by most adults when used at recommended doses. Mild side effects may include digestive upset, nausea, headache, or loose stools. These effects are typically dose-dependent and often resolve with continued use or dose reduction. Some individuals may experience temporary changes in menstrual patterns. Allergic reactions are rare but possible, particularly with evening primrose oil. Long-term safety data is limited, so extended use should be monitored by healthcare providers.

Interactions

GLA may interact with anticoagulant medications like warfarin, potentially increasing bleeding risk due to its effects on platelet function. Caution is advised when combining with other blood-thinning supplements such as fish oil, vitamin E, or garlic. GLA might enhance the effects of anti-inflammatory medications, potentially requiring dose adjustments. Phenothiazine medications used for psychiatric conditions may interact with evening primrose oil specifically. Always consult healthcare providers before combining GLA with prescription medications or other supplements.

Who should be cautious

Individuals with bleeding disorders or those taking anticoagulant medications should exercise caution and seek medical guidance before using GLA supplements. Pregnant and breastfeeding women should avoid GLA supplements unless specifically recommended by their healthcare provider, as safety data is insufficient. People with epilepsy should be particularly cautious with evening primrose oil, as it may lower seizure threshold in sensitive individuals. Those scheduled for surgery should discontinue GLA supplements at least two weeks prior to avoid potential bleeding complications.

Frequently asked questions

Is GLA better than fish oil?

GLA and fish oil serve different purposes and are not directly comparable. Fish oil provides omega-3 fatty acids (EPA and DHA) with well-established cardiovascular and brain health benefits, while GLA offers unique anti-inflammatory omega-6 benefits. Many people can benefit from both, and they can be used together safely under appropriate guidance.

How long does it take to see benefits from GLA?

Benefits from GLA supplementation typically become apparent after 6-12 weeks of consistent use. For skin conditions like atopic dermatitis, improvements may be noticed within 4-6 weeks. Individual responses vary based on factors like dosage, health status, and the specific condition being addressed.

Can I get enough GLA from diet alone?

It’s virtually impossible to obtain therapeutic amounts of GLA from food sources alone. Even foods with the highest GLA content require supplementation to achieve the doses used in clinical studies and associated with health benefits.

Should I take GLA with food?

Yes, taking GLA supplements with meals, particularly those containing some fat, can improve absorption and reduce the likelihood of digestive upset. The fat-soluble nature of GLA means it’s better absorbed when consumed with dietary fats.

Is GLA safe for long-term use?

While short to medium-term use appears safe for most adults, long-term safety data is limited. Extended use should be supervised by healthcare providers, with periodic assessment of benefits and any potential adverse effects.