Spinach extract effect potent enough to feature on WADA banned list, say researchers
The German-based research team provide evidence that ecdysterone, a naturally occurring steroid hormone found in spinach, combined with leucine exerts an anabolic-type effect that could contribute to sporting performance.
Its potency is such that the researchers recommend its inclusion on WADA’s prohibited substances and methods in sports in class S1.2 “other anabolic agents”.
“We saw drastic increases in maximum performance in bench press in the group that took ecdysterone," says co-author Dr Maria Parr, a researcher at Freie Universitat Berlin.
The research team had expected to see some impact on performance, but were surprised by the extent of the change, she adds.
Dr Parr notes that ecdysterone is known as “the Russian secret” for enhancing athletic performance several years ago.
Earlier in vitro and animal experiments showed that its effect on muscle cells, surpassing that of anabolic androgenic steroids, such as metandienone, which are prohibited in sports.
Four study groups
The double-blind 10-week intervention study, put athletes in one of four different groups: placebo group (PL, sample size (SS) = 12), ecdysterone1 group (Ec1, SS = 12), ecdysterone2 group (Ec2, SS = 10), and control group (CO, SS = 12).
The volunteers out of the Ec1 group took two capsules per day of a dietary supplement containing 100 milligrams (mg) of ecdysterone from spinach extract plus 100mg of leucine.
The Ec2 group took a high dosage of ecdysterone (eight capsules of “Peak Ecdysone” each day) over the entire intervention period. The PL group took two placebo capsules each day over the same period.
The CO group took only two capsules of the dietary supplement without training. Each group took half of their nutritional supplementation dose in the morning after breakfast and the other half on training days immediately after training or on non-training days in the evening.
In addition, the PL, Ec1, and Ec2 participated in a 10-week resistance-training program with three training sessions a week and a two split training plan. During this period, serum and urine samples were collected for further analyses.
Strength and performance gains
After the ten-week study period, the athletes who took ecdysterone showed a significantly higher increase in maximum muscle strength.
The participants from Ec1 and Ec2 increased their body weight significantly over ten weeks (Ec1 = 2.58 kilogram (kg) Ec2 = 3.11kg).
In change of muscle mass (MM), the Ec2 group increased MM more than two kg, while the PL reduced the MM by an average of 0.35kg.
The Ec1 group also increased their MM by an average of 1.58kg but without significant difference compared to PL.
After ten weeks of nonspecific bounce training, all three training groups increased their jump height (PL: 1.94 centimetres (cm); Ec1: 2.01cm; Ec2: 2.39cm).
All three training groups increased their one-rep max back squat. The PL group improved their squat from 107.5kg to 124.17kg.
Ec1 had an increase of 18.50kg from 104.17kg to 122.71kg, a 17.75% improvement and Ec2 from 100.50kg to 120.00kg, an improvement of 19.50kg or 19.4%.
The team also identified 6mg of ecdysterone per capsule for this product. Tests revealed no contamination of these products with substances that are prohibited in sports were found.
“This project demonstrates the performance-enhancing effect of ecdysterone in humans,” the study concludes. “Thus, our results strongly suggest including ecdysterone in class S1 “Anabolic Agents”.”
“Further investigations on the activity of ecdysterone are recommended. They should also include a controlled administration trial of ecdysterone in humans to elucidate the metabolism of ecdysterone and to evaluate possibilities for its improved detection in doping control analyses.”
The main caveat
Professor Parr further explained that the low dose of two pills per day, which they used for some of the participants in the experiment, would amount to anywhere between 250g and four kg of spinach per day, depending on the variety and harvesting of the plant.
A person would have to eat that amount every day over the course of ten weeks in order to consume the same amount as one of the “low-dose athletes” in the study.
In order to consume the same level as those administered high doses, a person would have to eat between one to 16 kilograms of spinach, she explained.
Source: Archives of Toxicology
Published online: doi.org/10.1007/s00204-019-02490-x
“Ecdysteroids as non‑conventional anabolic agent: performance enhancement by ecdysterone supplementation in humans.”
Authors: Eduard Isenmann et al