Evening primrose oil is best known as a supplement, but the fatty acid it contains, gamma-linolenic acid (GLA), also appears in a modest range of whole foods and plant oils. Understanding where GLA comes from in the diet, how the body makes it, and why many people still fall short can help you make smarter choices about both food and supplementation. This article pulls together what the current evidence says about foods high in evening primrose oil equivalents and related dietary sources of GLA.
What Is GLA and Why Does the Source Matter?
Evening primrose oil (EPO) is valued almost entirely because of its unusually high concentration of gamma-linolenic acid, an omega-6 fatty acid with anti-inflammatory properties. EPO itself is extracted from the seeds of Oenothera biennis and is not found in meaningful quantities in common foods. However, GLA is the compound that does the biological work, and GLA does appear in several other plant oils and seeds, making it possible to obtain some through diet.
GLA sits in the omega-6 pathway between linoleic acid (LA) and arachidonic acid. The body can theoretically produce GLA by converting LA using an enzyme called delta-6-desaturase. This means that, strictly speaking, evening primrose oil is not an essential dietary requirement in the way that, say, vitamin C is. The real question is whether your body converts enough LA into GLA to meet your needs, which is a question with a complicated answer.
For a deeper look at how GLA works once absorbed, see our article on the science behind GLA and its effects on the body.
Foods High in Evening Primrose Oil Equivalents (GLA Sources)
Pure evening primrose oil is not a food you will find in a grocery store produce aisle. However, several seed oils and whole foods provide meaningful amounts of GLA. Here is a breakdown of the most well-documented dietary sources.
Borage Oil
Borage seed oil (Borago officinalis) contains the highest concentration of GLA of any commonly available plant oil, typically around 20 to 26 percent GLA by weight. It is sold as a culinary oil in some specialty stores and as a supplement. Cold-pressed borage oil is the most GLA-rich option among oils you can actually consume as food, and it is a realistic dietary alternative to EPO supplements for people looking to increase GLA intake through cooking fats.
Black Currant Seed Oil
Black currant seed oil is another concentrated plant source, with GLA content typically ranging from 15 to 20 percent. Unlike many other GLA-rich oils, black currant oil also provides some alpha-linolenic acid (ALA), an omega-3 fatty acid, which may help balance the omega-6 load. Black currants are more commonly consumed as a whole fruit or juice, but the GLA is concentrated in the seeds, making the extracted oil a better source than eating the berries themselves.
Hemp Seeds and Hemp Seed Oil
Hemp seeds and cold-pressed hemp seed oil provide a smaller but still notable amount of GLA, generally estimated at around 1 to 4 percent of total fatty acids. Hemp seeds are widely available, easy to add to smoothies or salads, and provide a useful ratio of omega-6 to omega-3 fats. While hemp is not a high-GLA source in the same league as borage or black currant oil, it is one of the most practical whole-food ways to get some dietary GLA regularly.
Spirulina
Spirulina, the blue-green algae sold as a powder or tablet, is one of the few non-oil food sources that contains measurable GLA. The amounts are modest and vary by product, but spirulina is notable because it provides GLA in a whole-food matrix alongside protein, B vitamins, and other nutrients. It is unlikely to be a primary GLA source for most people but contributes to overall intake for those who use it regularly.
Oats
Oats contain trace amounts of GLA, though in quantities too small to be considered a meaningful source on their own. They appear here because some older nutritional literature lists them as a dietary contributor, and they form part of the background GLA intake in diets based on whole grains. Do not rely on oats as a GLA strategy, but they do contribute at the margins.
Top Dietary Sources of GLA at a Glance
| Food / Oil | Approximate GLA Content | Practical Availability |
|---|---|---|
| Borage seed oil | 20 to 26% of fatty acids | Specialty stores, online |
| Evening primrose oil (supplement) | 8 to 14% of fatty acids | Health stores, online |
| Black currant seed oil | 15 to 20% of fatty acids | Specialty stores, online |
| Hemp seed oil | 1 to 4% of fatty acids | Most supermarkets |
| Hemp seeds (whole) | Trace to low amount | Most supermarkets |
| Spirulina | Small, variable amount | Health stores, online |
| Oats | Very small trace amount | Universal |
The Body’s Own GLA Production: Precursors and Conversion
Because the human body can make GLA from linoleic acid (LA), the foods you eat that are rich in LA technically support GLA levels, as long as the conversion enzyme is working properly. Linoleic acid is abundant in sunflower oil, safflower oil, corn oil, soybean oil, walnuts, and most nuts and seeds. Most people eating a standard Western diet consume more than enough LA.
The bottleneck is the enzyme delta-6-desaturase, which converts LA into GLA. Several dietary and lifestyle factors are known to inhibit this enzyme:
- High intake of trans fatty acids (partially hydrogenated oils)
- Excess saturated fat intake
- High alcohol consumption
- Zinc, magnesium, or vitamin B6 deficiency
- High blood sugar or insulin resistance
- Ageing, which naturally reduces enzyme activity
Conversely, ensuring adequate intake of these micronutrients and limiting trans fats may support the body’s natural GLA synthesis from dietary LA. This is a realistic dietary strategy worth considering before turning to supplements.
Who May Struggle to Get Enough GLA from Diet Alone
For most healthy adults eating varied diets, background GLA intake from food combined with the body’s own conversion is probably sufficient. However, several groups may have genuinely reduced GLA status and might benefit from either GLA-rich foods or supplementation:
- Older adults: Delta-6-desaturase activity declines with age, reducing endogenous GLA production even when LA intake is adequate.
- People with diabetes or metabolic syndrome: Insulin resistance impairs the conversion enzyme, a finding supported by multiple studies on diabetic neuropathy and GLA.
- Those with atopic conditions: Research has suggested that people with eczema or atopic dermatitis may have an inherent defect in delta-6-desaturase function, meaning dietary LA converts poorly to GLA.
- People following very low-fat diets: Severely restricting all fats limits both GLA intake and the substrate needed for conversion.
- Heavy alcohol users: Alcohol directly inhibits the conversion enzyme and disrupts fatty acid metabolism broadly.
If you fall into one of these groups, simply eating more sunflower seeds may not move the needle much. This is the context in which EPO and other GLA-rich supplements become more clinically relevant. For more detail on when supplementation may be appropriate, see our guide to evening primrose oil supplements and evidence-based uses.
Dietary Sources vs. Supplements: An Honest Comparison
EPO supplements are standardised, meaning the amount of GLA per capsule is known and consistent. A typical EPO capsule (1000 mg) delivers roughly 80 to 140 mg of GLA, depending on the product. Achieving that same dose through diet alone would require daily servings of borage or black currant seed oil, which is possible but not common in practice for most people.
Dietary sources like hemp seeds and spirulina provide GLA in much smaller, less predictable amounts, but they come packaged with fibre, protein, and other phytonutrients that supplements do not offer. Borage oil is the one dietary oil that genuinely competes with EPO on a per-millilitre GLA basis, but it is also the least commonly used in everyday cooking.
For general wellness and background GLA support, a diet that includes hemp seeds, some cold-pressed seed oils, and limiting trans fats is a sensible first step. For specific therapeutic purposes, the standardised doses available in EPO supplements are generally what the clinical research has tested. The NIH Office of Dietary Supplements maintains updated factsheets on essential fatty acids and related nutrients that are worth consulting for the latest evidence.
You can also review our full section on omega-6 fatty acids and inflammation for broader context on where GLA fits in the diet.
Frequently Asked Questions
Can I get enough GLA from food without taking evening primrose oil capsules?
For most healthy people, modest dietary GLA from hemp seeds and cold-pressed oils, combined with the body’s own conversion of linoleic acid, provides a baseline level of GLA. However, achieving the doses used in clinical research on conditions like eczema or nerve pain through diet alone is challenging without regularly consuming concentrated oils like borage or black currant seed oil. If you have a specific health goal in mind, it is worth discussing with a healthcare provider whether food sources are realistic for your situation.
Is borage oil safer than evening primrose oil as a food source?
Borage seed oil contains higher concentrations of GLA than EPO, but some borage products also contain pyrrolizidine alkaloids (PAs), plant compounds that are toxic to the liver in large amounts. Look for products that are certified PA-free if using borage oil regularly. Cold-pressed evening primrose oil does not carry this concern, which is one reason EPO remains the more commonly recommended supplement despite borage oil’s higher GLA content.
Do any common vegetables or fruits contain GLA?
GLA is not meaningfully present in most vegetables or fruits. The compound is found primarily in seed oils of specific plants. Spirulina is a partial exception in that it is a whole-food source rather than an extracted oil, but even there the amounts are modest. For practical purposes, if you want dietary GLA, you are looking at seed oils and hemp seeds rather than the fruit and vegetable section of the grocery store.
Does eating more sunflower or safflower seeds increase GLA levels?
These seeds are rich in linoleic acid, the precursor to GLA, so in theory increasing intake can raise GLA production through the body’s conversion pathway. In practice, how much GLA this produces depends heavily on the efficiency of your delta-6-desaturase enzyme. For people with healthy metabolisms and no inhibiting lifestyle factors, this approach has merit. For people with diabetes, older age, or high trans fat intake, the conversion may be too limited for this strategy to be effective on its own.
Are there any dietary habits that actively reduce GLA levels?
Yes. A high intake of trans fatty acids, which are found in partially hydrogenated oils and some processed foods, directly competes with and inhibits delta-6-desaturase. Excess alcohol and a diet low in zinc, magnesium, or vitamin B6 also reduce conversion. Keeping these factors in check is arguably as important as worrying about which GLA-rich foods to add, particularly for people who already eat a reasonably varied diet with adequate linoleic acid.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.
