Post-Marathon Immune Suppression
Reference: Bouic PJD, Clark A, Lamprecht J, Freestone M, et al. The effects of ß-sitosterol (BSS) and
ß-sitosterol glucoside (BSSG) mixture on selected immune parameters of marathon runners: inhibition of post marathon immune suppression and inflammation. Int J Sports Med 1999; 20:258-62.
Study: In this controlled investigation, a group of 17 athletes (11 males, 6 females; age range 26 to 51 years) from a running club in Cape Town, South Africa were randomly assigned to one of two treatment groups four weeks prior to the 68 km Two Oceans Marathon. After randomization, runners in group B were given a BSS:BSSG mixture (20 mg BSS and 0.2 mg BSSG, Moducare®) three times a day while those in group A were given placebo capsules at the same dosing schedule. Extensive laboratory analysis including a full blood count, liver function tests, markers of immunity (CD3, CD4, etc), cortisol, and DHEA-s was performed on each volunteer at baseline and three days after completion of the marathon.
Results: A reduction in lymphocytes (lymphopenia) is common after strenuous exercise and the data presented by Dr. Bouic and associates confirms this. The percentage of lymphocytes decreased in the placebo group from 39.0 to 33.8% by the end of the trial, while those marathoners employing Moducare® remained stable in their lymphocyte count. Moreover, those using Moducare® had significant increases in CD3 and CD4 levels compared to the placebo group suggesting that these supplemented runners were less likely to be immunosuppressed after the marathon. In addition, those taking Moducare® had significant reductions in the pro-inflammatory monokine IL-6 from 225 IU/ml to 190 IU/ml post race. In contrast, the placebo group showed an increase in IL-6 from 184 IU/ml to 236 IU/ml at the end of the study.
Cortisol, an adrenal and stress-related immuno-suppressive hormone, rose significantly by 38.9 nmol/l in the placebo group but decreased slightly by 7.5 nmol/l in the active group by the conclusion of the trial. In addition, both groups experienced a non-significant increase in DHEA-s levels from 4.0 to 4.4 µmol/l and from 4.2 to 5.0 µmol/l in the placebo and Moducare® groups respectively. The cortisol/DHEA-s ratio in the Moducare® treated group had a significant 22.8 point reduction compared to only a 3.4 point reduction in the placebo group.
In those runners employing Moducare®, there was a non-significant increase by 4.5% in white blood cells and 5.4% in neutrophils compared to baseline values. By comparison, placebo subjects exhibited a significant 13.6% and 23.0% increase in white blood cells and neutrophils respectively.
Clinical Summary: Although gentle exercise is known to increase immunity, strenuous exercise can temporarily suppress the immune system. Supplementation with Moducare® may help those athletes or "weekend warriors" engaged in a difficult training program from catching the flu bug by improving their immunity and decreasing the immunosuppressive inflammatory response associated with their exercise.
