Look through the annals of triathlon and you’ll come across myriad triathletes breaking down through stomach issues. Paula Newby-Fraser, Sian Welch, chap bent double at Perranporth circa 2008… (ahem, me). When it comes to tri, especially Ironman, gastro-distress is common. Well, according to Kent University research, the situation could be prevented by a combination of zinc-carnosine and colostrum (a cow’s first milk).
According to the study, this supplement mix reduced the incidence of a phenomenon known as ‘leaky gut’, a condition where the thin mucosal barrier of the gut becomes more permeable and, in turn, less effective. This is key because that barrier plays a major role in absorbing nutrients, as well as preventing large molecules and germs from the gut entering the bloodstream. Why is this key to triathletes?
“Gut permeability increases through several mechanisms related to exercise,” explains Dr Glen Davison, one of the lead authors of the study. “Core temperature is one. Others include oxidative stress, ischaemia [lower oxygen availability to the gut as blood’s diverted to working muscles and skin] and the mechanical stress from running.”
Davison took eight sportsmen and had them complete a 20min run on a treadmill, with 1% gradient, at a speed equivalent to 80% of their VO2max. Factors like core body temperature were measured and blood was taken before and after. The subjects repeated the test after 14 days supplementation of either a placebo, zinc-carnosine only, colostrum only or a combination of zinc-carnosine and colostrum.
Across all tests, core temperature rose by 2°C. In the placebo group, this caused doubling of apoptosis while reducing epithelial resistance threefold – both of these physiological mechanisms play a key role in gut permeability. However, after the 14-day supplementation period, the zinc-carnosine colostrum mix truncated these effects by up to 50%. How?
“The supplements protect the intestinal cells against the negative impact of factors like raised core temperature,” says Davison. “For instance, they augment the production of Heat Shock Proteins (HSP).” This acts like an intestinal shield and so reduces gut permeability. Another finding is that even when damage does occur, this combination increases the gut recovery period.
So how do you know if leaky gut is causing your race-related gastro-distress? “The most common symptoms are nausea, vomiting, cramping, diarrhoea and even GI bleeding,” adds Davison. But Davison adds that this mix could benefit any athlete because of its positive impact on nutritional absorption.
The study’s dosage comprised 37.5mg zinc-carnosine and 10g bovine colostrum taken twice daily. Try this for 14 days, and definitely in training first, just to ensure no repercussions.
Looking to keep the cost down? Davison and his team showed that zinc-carnosine and colostrum taken alone both strengthen the gut’s defences against permeability issues, though to a lesser extent than the combo.
This combination could have a particularly significant impact when racing or training in the heat because of the gastro-related issues tied in with raised core temperature. Again, try in training before the races.