Omega 3 and injuries in runners: the Equipe Enervit study

 

Stefano Righetti - Equipe Enervit.

Summary
A study conducted by researchers at Equipe Enervit and recently published in the European Journal of Sport Science (EJSS), reveals that the probability of injury in runners is strongly correlated to low Omega-3 Index levels and a high AA/EPA ratio. This is more than the other risk factors known so far.

In runners, the risk of overload injury is very frequent, with an incidence of between 2.5 to 33 injuries per 1000 hours of running. It occurs when the repeated load on tendons, joints, and muscles exceeds the tissue's ability to adapt. There are many factors that can affect the potential for overload injury, such as the volume/frequency/intensity of training or the characteristics of the athlete (years of activity, age, BMI).

However, although omega-3 has been shown in the past to positively modulate inflammation, oxidative stress, and markers of post-activity muscle damage, there hasn’t been any evidence that a dietary intervention or variable could be correlated with the likelihood of injury until now.

The Equipe Enervit study on runners
275 runners over the age of 18 were enrolled. None of them were taking omega-3 or antioxidant supplements. All of them had been training three or more times a week for at least a year. Each of them was subjected to a questionnaire, with the aim of collecting training characteristics and any overload injuries from the previous 12 months. At the same time, they were given a finger capillary blood draw to assess their Omega-3 Index and AA/EPA ratio.

50% of the runners had suffered an overload injury.
The subjects were 73.5% male with a mean age of 41.20 ± 12.47 years, who had been training for 8.53 ± 8.29 years, for 49.72 ± 23.27 km/week, and had been competing for 12.95 ± 12.11 years. In the previous year, 50.9% had suffered an overload injury. Interesting to note, those who had run into this type of injury recorded lower Omega-3 Index values (3.35 ± 1.63 VS 4.58 ± 1.50, p<0.0001) and higher AA/EPA values (20.84 ± 8.97 VS 17.70 ± 7.86, p=0.002).

Low blood omega-3 levels, high AA/EPA ratio = higher risk of injury
Within a multivariate analysis in which several variables, known from the literature to be predisposed to injury, i.e., age, BMI, years of training, number of races per year, and training km per week, were also taken into consideration. Lower blood omega-3 values and high AA/EPA ratio were the factors most strongly associated with risk of stress injury in the previous 12 months (Omega-3 Index Exp β = 0. 387; 95% CI 0.287-0.544; p < 0.0001; AA/EPA Exp β =1.927; 95% CI 1.88-1.97; p = 0.008).

Not only that, those runners who had had repeated injuries in the previous year had lower Omega-3 Index values and higher AA/EPA values compared with those who had had only one injury.

Bottom line.
Reduced blood levels of Omega-3 Index (EPA+DHA) and a high ratio of Omega-6/Omega-3 (AA/EPA) are strongly associated with the risk of overload injury in runners. Taking supplements containing omega-3 and decreasing dietary intake of omega-6 may potentially reduce the likelihood of injury.

Bibliography
Sergio Davinelli, Mariano Intrieri, Sawan Ali, Stefano Righetti, Luca Mondazzi, Giovanni Scapagnini & Graziamaria Corbi. Omega-3 Index and AA/EPA ratio as biomarkers of running-related injuries: An observational study in recreational runners. European Journal of Sport Science, 2021 Nov 18:1-9.