Colostrum is widely marketed as a dietary supplement for immune support. Popular brands include GNC, Jarrow, Source Naturals, Symbiotics, and NOW. When I saw it on the shelves at Whole Foods, I decided to check out in the medical literature.
Mammals produce colostrum as the first milk after a baby is born. The products commonly available come from cows. Colostrum contains oligosaccharides, growth factors, antimicrobial compounds, and immune-regulating constituents as well as the protein, carbohydrates, and fat found in ordinary milk. It is believed to be important for development of the baby's immune system. But does colostrum from cows help the human immune system?
An Australian study showed that bovine colostrum supplements improved immune parameters and decreased the incidence of upper respiratory illness in highly trained cyclists. In a similar study on sore throat in military personnel, a Norwegian study showed no difference between colostrum and placebo. A study of healthy volunteers aged 40 – 80 in the Netherlands showed a positive effect of vitamins and zinc on immune function, but no effect of colostrum.
Bovine colostrum products vary according to the breed and health of the cow, as well as the time of collection. There is a technique to improve the effectiveness of colostrum against specific bacteria: the cow can be vaccinated while she is pregnant. Hyperimmune bovine colostrum (HBC) is then the first milk she produces after the calf is born. HBC has been used successfully to treat cryptosporidium, H. pylori, rotavirus, and shigella infections.
Colostrum contains growth factors as well as immune components. Bovine colostrum has been used by athletes in an attempt to build muscle and enhance exercise performance. The results were modestly positive. There is also some evidence that colostrum may protect the gastrointestinal tract against inflammation from non-steroidal anti-inflammatories.
The safety of bovine colostrum appears to be comparable to that of ordinary cow's milk. Minor gastrointestinal complaints, including flatulence and nausea, have been reported.