Gamma-linolenic acid found to help relax constricted coronary arteries

Medical Xpress / Toho University / Journal of Pharmacological Sciences ^ | June 25, 2025 | Keisuke Obara et al

[ConservativeMind]

A new study by Toho University has revealed that gamma-linolenic acid (GLA), a fatty acid commonly found in plant oils such as evening primrose and borage, can directly relax constricted coronary arteries by blocking a key receptor involved in blood vessel contraction. This discovery offers promising implications for the prevention of coronary spasms and angina.

Coronary artery spasms—sudden narrowing of the arteries supplying the heart—can lead to chest pain (angina) and increase the risk of heart attacks. The underlying cause often involves the activation of prostanoid TP receptors, which trigger vessel contraction in response to chemical signals like thromboxane A2 and prostaglandin F2α.

In this study, the Toho University team investigated whether GLA, an omega-6 polyunsaturated fatty acid, could block these contractions in isolated pig coronary arteries. They found that GLA selectively inhibited contractions induced by TP receptor agonists, while having little effect on other contraction triggers. Additional experiments confirmed that GLA acts as a competitive antagonist of the TP receptor—similar to omega-3 fatty acids such as EPA and DHA.

"Surprisingly, GLA—a non-omega-3 fatty acid—showed the same ability as omega-3s to inhibit TP receptor signaling," said lead researcher Dr. Obara. "This challenges the previous belief that only omega-3 fatty acids have this vascular effect."

Importantly, the concentrations of GLA used in the experiments correspond to levels achievable through dietary supplementation. GLA is also metabolized into compounds that can suppress inflammation, adding to its potential cardiovascular benefits.

These findings suggest that dietary GLA might help reduce the risk of coronary spasms and related heart conditions by blocking TP receptors in coronary arteries. However, further studies are needed to explore its effects in humans and confirm its long-term safety.

[ConservativeMind]

GLA is a converted form of Omega-6 fat. GLA and Omega-3 fats can both relax these vessel contractions.

Because it is useful for other things, I have taken it via borage or black currant oil for over two decades.

[ConservativeMind]

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[ChildOfThe60s]

If I recall correctly primrose oil is also another good source of GLA

[nickcarraway]

Still skeptical of this study and waiting for more studies.

[DAC21]

Could you link what supplements you have purchased over the years for GLA?

Thanks

[sauropod]

Bkmk

[GaltAdonis]

As well as borage oil and black currant seeds are good sources also.
That’s what I hear anyway.

[ConservativeMind]

Swanson EFAs Black Currant Seed Oil

https://www.swansonvitamins.com/p/swanson-efas-black-currant-seed-oil-gla-omegatru-180-sgels

NOW Foods Supplements, Black Currant Oil 500 mg with 70mg of GLA (Gamma-Linolenic Acid), 100 Softgels

https://www.amazon.com/gp/aw/d/B000O2TNKW

NOW Foods Supplements, Borage Oil 1000 mg with 240mg of GLA (Gamma Linolenic Acid), 120 Softgels

https://www.amazon.com/gp/aw/d/B0013OQIX0

The NOW borage oil and Swanson black currant oil are both top rated in the latest ConsumerLab.com review.

I went into my purchase histories at both companies. Swanson can have the best price, but you need to get their near daily sale emails and link to their website through that promo email to get it.

You can often save a lot and time and again Swanson and NOW Foods are independently shown to have great quality.

[DAC21]

Thank you!