Colostrum - the fluid produced by cows during the first 48 hours after giving birth - may boost the immune systems of top athletes.
The fluid passes on the immunities of a cow to her calf when it first suckles after birth, but Massey University researcher Christine Crooks says the effect can also work when humans drink the milk.
Her study shows that colostrum supplements boost immunity levels in marathon runners.
She said such supplements could provide an answer to one of nature's curious ironies - why ultra-fit long-distance athletes were more prone to colds than the average weekend jogger.
A key factor appeared to be a fall in the levels of secretory immunoglobulin A (s-IgA) - the body's first line of defence against infection - after intense bouts of exercise.
Ms Crooks looked at male and female runners aged 25 to 58 years, all of whom trained for the 2002 Rotorua Marathon.
The athletes were running an average 43km a week, with a top-end range of 105km. Half were given drinks made with powdered colostrum - which sells for $1000/kg in export markets - and half a similar drink without colostrum.
The research, sponsored by Fonterra's health division, found that levels of s-IgA in the colostrum group were almost double those of the control group.
The runners' s-IgA levels were measured before supplements were given, monthly during the study and two weeks after the marathon.
Diet, training and health records were also kept.
Fonterra's health platform manager, Liz McMaster, said the research suggested that colostrum might enhance athletes' immunity and help to prevent upper respiratory tract infections that runners often report, typically about 14 days after marathon-type race events.
Fonterra has been paying farmers $168/kg for 0.75 per cent strength colostrum.
Other studies have shown colostrum can also boost growth and healing in humans, specifically in muscle and skin tissues.
- NZPA
Herald Feature: Health
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