The Latest Way to Dope is…Worm Blood?

A novel substance has made a blip on World Anti-Doping Agency’s radar—the extracellular hemoglobin from Arenicola marina lugworms, a humble invertebrate used as bait.

That’s right, the common sandworm, often found on beaches and used to fish for cod.

In 2007, a French marine biologist, Dr. Franck Zal, discovered that lugworm hemoglobin, 250 times smaller than human hemoglobin, is able to carry 40 times more oxygen. Zal immediately saw usefulness in medicine, particularly for organ transplants, but also the potential for misuse as a performance enhancer in sports. Predictably, Zal told l’Equipe, in 2020, a pro cyclist approached him about obtaining some of the product from Zal’s company, Hemarina.

How does worm doping work?

Triathlete spoke with Mario Thevis, one of the authors of a paper on detection of lugworm hemoglobin in doping control published in Analytical Science Journals. The holy grail of endurance athletes is to improve the oxygen delivery capacity of the blood, Thevis said. Some ways to do that artificially include blood transfusions, erythropoiesis-stimulating agents (EPO), and hemoglobin-based oxygen carriers (HBOCs), which includes lugworm hemoglobin. These are all prohibited in and out of competition.

Does it actually work?

“Improving preoperative organ transplant conditions has been one of the first applications of lugworm hemoglobin,” Thevis wrote via email. “Whether or not it de facto can also improve athletic performance has, to my knowledge, not been studied yet. However, if some limitations associated with earlier generations of substances designed as blood substituents are eliminated, this product might have the potential to enhance endurance performance.”

Worm advantages over other doping agents

The Hemarina website lists advantages over other blood substitutes: “In addition to super oxygen transport, [lugworm hemoglobin] can be stored at room temperature, is compatible with all blood types, and doesn’t cause elevated hematocrit levels or blood pressure.” Thevis, et al, noted  that “some early HBOCs had adverse effects such as hypertension and renal toxicity.”

Lugworm hemoglobin, on the other hand, is generally well tolerated, and “has a high oxygenation potency, especially in poorly vascularized tissue. It also has potential antioxidant, anti-inflammatory, and anti-bacterial effects.” Unlike blood transfusions and EPO, “there is no need for blood group matching, the risk for pathogen transmission is significantly reduced, logistic requirements are simple, and effects occur immediately following infusion.”

From animal studies, we know lugworm hemoglobin has a short half-life, which can be both an advantage and disadvantage. Its benefits are fleeting, so in competition, it would need to be infused close to the start of the race, especially one of long duration like a long-course tri. That could be logistically difficult for a cheating athlete.

By the same token, Thevis, et al found that the window of detection by doping control is four to eight hours after infusion, so it would likely have cleared an athlete’s system by the completion of a 70.3 or longer event. Like other doping agents, lugworm hemoglobin would most likely be used out of competition to increase an athlete’s ability to tolerate heavy training loads, recover, and improve.

Is worm doping banned?

Yes – but not so much the substance as the method. According to WADA, “Use of this product is regarded as a prohibited method…which includes artificially enhancing the uptake, transport or delivery of oxygen.” Manipulation of blood and blood components was prohibited even before WADA came into being in 2004. Thevis wrote, “WADA-accredited anti-doping laboratories are prepared to detect this substance, enabled primarily by its non-human nature and composition.”