Zinc carnosine shows gut health benefits for athletes: RCT data

Supplements of zinc carnosine with or without bovine colostrum may protect against gut symptoms associated with heavy exercise, says a new study with implications for athletes and military personnel.

Exercise, heat stress, and nonsteroidal anti-inflammatory drugs (NSAIDs) can affect the integrity of the lining of the gut and affect the integrity of the gastrointestinal tract to produce a situation called leaky gut. The junctions between cells in the lining of the intestine (epithelial cells) usually prevent passage of toxic bacterial components from the gut lumen into the blood. However, stress can weaken the structure of these so-called Tight Junctions, and allow the absorption of toxins.

New data published in the American Journal of Clinical Nutrition indicated that zinc carnosine may improve the health of the epithelium and the tight junction structure in people undertaking exercise.

Scientists from five different English universities report that the potential benefits were enhanced with adding bovine colostrum to the supplementation regimen, and that the effects were observed more rapidly in the combined group.  

“The findings of additive or synergistic effects (dependent on the variable measured) were particularly relevant in the clinical study because it was only the combination treatment that was effective after 2 days of treatment,” wrote the researchers, led by Raymond Playford from Plymouth University.

“This result suggests that short courses taken for a few days before embarking on prolonged heavy exercise (such as athletic events or military maneuvers in hot climates) could provide optimal results while minimizing dosing.”

Study details

Playford and his co-workers recruited eight volunteers to participate in their four-arm, double-blind, placebo-controlled crossover study. Participants were randomly assigned to 14 days of supplementation with zinc carnosine (37.5 mg). colostrum (10 grams), zinc carnosine + colostrum, or placebo twice per day. The intervention was followed by a two week “washout” period before crossing over to a different group. By the end of the study, all of the participants had been in each of the different supplementation groups.

Results showed that exercise resulted in a body temperature increase of 2°C and 3-fold increases in gut permeability. However, these increased were reduced by 70% by zinc carnosine or colostrum supplementation after 14 days, said the researchers.

When combined, the benefits were observed within two days, they added.

“There is currently a demand by the general public for more natural types of products, which are often termed alternative or complementary therapies or nutriceuticals (from nutrition and pharmaceuticals),” wrote the researchers. “Because of their natural origin, the general public often assumes that they are safe and may take high doses for prolonged periods. However, caution needs to be taken because there is biological activity in many of these products such as colostrum, which is rich in multiple growth factors.

“Therefore, general principals of the use of the lowest dose for the shortest time possible seem appropriate. In the current studies, ZnC was administered at 37.5 mg 2 times/d, which provided a total daily dose of 16 mg Zn/d. Current recommendations for daily zinc intake are 5.5–9.5 mg (for men) and 4–7 mg (for women) from a United Kingdom food-standards authority and 11 mg (for men) and 8 mg (for women) from the US NIH with daily upper recommended limits being 25 mg/d in the United Kingdom and 40 mg/d in the United States. Therefore, the regimen that was used in the current studies was well within the safety guidelines.”

“Our current studies focusing on temperature changes build on previous work that showed ZnC prevents NSAID gut damage. Therefore, it would be of interest to examine the effects of ZnC on other gut disorders, such as inflammatory bowel disease, in which an uncontrolled inflammatory response combined with the disruption of epithelial integrity is a major factor,” they concluded.

Source: American Journal of Clinical Nutrition

Published online ahead of print, doi:10.3945/ajcn.116.134403

“Zinc carnosine works with bovine colostrum in truncating heavy exercise–induced increase in gut permeability in healthy volunteers”

Authors: G. Davison, T. Marchbank, D.S. March, R. Thatcher, R.J. Playford