Bovine colostrum

What it is

Bovine colostrum is the first milk a cow produces in roughly the first two days after calving, collected and usually spray-dried into a powder. Compared with ordinary cow's milk it is much more concentrated: about double the total solids and fat, around five times the protein, and far higher levels of immunoglobulins and lactoferrin. It also carries cytokines, immune regulatory factors and growth factors including IGF-1. It is sold as a food supplement rather than a medicine.

What the research says

The best evidence is for two narrow things and it is not strong evidence. Pooled randomised trials in people doing regular exercise training suggest fewer days and episodes of upper respiratory symptoms, but the trials are small and most were judged at moderate or high risk of bias. A meta-analysis of gut permeability markers found a statistically significant reduction in urinary sugar ratios, with very high heterogeneity. Where researchers measured immune markers directly, pooled results showed no meaningful effect, so the mechanism claimed on labels is not demonstrated. Claims about body composition and physical performance are not supported.

Evidence grade: Limited evidence.

What goes wrong

A teenager with persistent cow's milk allergy had anaphylaxis after a bovine colostrum cream was applied to a surgical wound. (Source 1)

• Case report, Very low certainty.
• Size: 1 patient.
• Who: 16-year-old boy with persistent cow's milk allergy.
• How long: Single exposure.
• Result: One episode of anaphylaxis after cutaneous application to a surgical wound; UniCAP testing showed a significant elevation in specific IgE antibodies to whey milk proteins.
• Funding: not stated.

We describe the case of a 16-year-old Caucasian boy with a clinical history of persistent cow's milk allergy (CMA), who developed one episode of anaphylaxis following cutaneous application of a bovine colostrum containing cream to a surgical wound.

In that same case the reaction began within minutes of skin contact and settled only after emergency drug treatment. (Source 2)

• Case report, Very low certainty.
• Size: 1 patient.
• Who: 16-year-old boy with persistent cow's milk allergy.
• How long: Single exposure.
• Result: Urticaria, itching and wheezing within a few minutes; symptoms disappeared after epinephrine 330 mcg, hydrocortisone 200 mg and chlorpheniramine maleate 10 mg.
• Funding: not stated.

Urticaria, itching, and wheezing occurred immediately within few minutes and symptoms disappeared after systemic epinephrine (Fastjekt 330 mcg), hydrocortisone (200 mg), and chlorpheniramine maleate (10 mg) administration.

Trials in the exercise review reported mild stomach problems in one study and none in others, but the review says it cannot tell whether side effects were absent or simply not measured. (Source 3)

• Systematic review, Very low certainty.
• Size: 5 trials, 152 participants.
• Who: Healthy adults in exercise training.
• How long: 8 to 12 weeks.
• Result: Mild stomach problems in females only in one trial; no side effects reported in another; no reporting in the rest.
• Funding: No sponsors or sources of funding were used to prepare the review.

One study included in this review reported side effects presenting as stomach problems, in females only, which were mild and generally disappeared with time.

The World Anti-Doping Agency stated in 2013 that bovine colostrum contains growth factors that could affect a doping test and said it does not recommend consumption, while not prohibiting it. (Source 4)

• Official position, Certainty not rated.
• Size: Not applicable.
• Who: Competitive athletes subject to anti-doping testing.
• How long: Position first published in 2013.
• Result: Not recommended for consumption by WADA; not on the prohibited list.
• Funding: Not applicable.

which could influence the outcome of a doping test, and for this reason they do not recommend its consumption. However, bovine colostrum is not prohibited

What the evidence supports

Pooled randomised trials in exercising adults found fewer upper respiratory symptom days and episodes with bovine colostrum than placebo, but most trials were at moderate or high risk of bias. (Source 5)

• Meta-analysis, Low certainty.
• Size: 152 participants across 5 trials.
• Who: Healthy adults aged 18 or over engaged in regular exercise training.
• How long: 8 to 12 weeks of follow-up.
• Result: URS days rate ratio 0.56, 95 % CI 0.43 to 0.72, P < 0.001; URS episodes 0.62, 0.40 to 0.99, P = 0.04 (44 % and 38 % reductions)
• Funding: No sponsor funding for the review itself; one author's doctoral work was linked to a colostrum supplier, per the paper's competing interests.

Over an 8–12 week follow-up period, bovine colostrum supplementation when compared to placebo significantly reduced the incidence rate of URS days (rate ratio 0.56, 95 % confidence intervals 0.43 to 0.72, P value < 0.001) and URS episodes (0.62, 0.40 to 0.99, P value = 0.04) by 44 and 38 % respectively.

A narrative systematic review of nine studies in athletes, which tabulated the included results without pooling them, reported that bovine colostrum supplementation helps to reverse exercise-induced gut permeability, while its own authors state that well-designed, placebo-controlled, randomized studies are still needed. (Source 6)

• Systematic review, Very low certainty.
• Size: Nine studies met the eligibility criteria, from 60 articles retrieved; the review does not report a combined number of participants.
• Who: Athletes.
• How long: Not stated in the abstract; varied across the included studies.
• Result: No pooled numeric estimate exists: the review performed no meta-analysis and states that 'A quantitative representation using a table, without performing further statistics, was obtained.' It therefore reports direction of effect only, with no effect size, no confidence interval and no GRADE certainty rating. The authors give as a limitation the small number of available studies and the different research protocols used across them, and call for well-designed, placebo-controlled, randomized studies of long-term safety and efficacy.
• Funding: Independent: the article states it received no external funding.

The data analysis revealed that vigorous exercise profoundly increases intestinal permeability, and BC supplementation helps to reverse gut permeability in athletes.

What the evidence does not support

A narrative review of sport and exercise research concluded there is limited evidence that bovine colostrum changes body composition or physical performance. (Source 7)

• Expert review, not systematic, Low certainty.
• Size: Not stated; narrative synthesis.
• Who: Athletes and physically active people.
• How long: Studies of varying length over about 25 years.
• Result: Limited evidence for body composition and physical performance; stronger evidence for gut permeability and illness risk.
• Funding: not stated.

Although some studies have shown protection against performance decrements caused by periods of intensified training, there is limited evidence for effects on body composition and physical performance.

One small double-blinded, placebo-controlled trial in ten young men found that bovine colostrum did not change plasma intestinal fatty acid-binding protein, a marker of gut cell damage, at any time point after exercise in a hot and humid environment. (Source 8)

• Randomized trial, Very low certainty.
• Size: 10 male participants (20 +/- 2 years) in a single trial; this is one trial, not a pooled or replicated result.
• Who: Young men exercising in a hot and humid environment.
• How long: Measurements pre-exercise, post-exercise, 1 h and 4 h after exercise.
• Result: I-FABP similar between colostrum and placebo at every time point (e.g. post-exercise 1505.10 +/- 788.63 pg/ml colostrum vs 1267.12 +/- 521.51 pg/ml placebo); I-FABP rose from pre to post exercise in both arms by 162 +/- 50% (colostrum) and 162 +/- 56% (placebo), p < 0.05, so colostrum did not blunt that rise. With ten participants the trial is far too small to exclude a modest effect, and its own conclusion is conditional on the hot and humid conditions tested rather than a general null.
• Funding: not stated.

I-FABP concentrations were similar between conditions at all time points

A systematic review and meta-analysis of randomised trials in trained and physically active people found no significant effect of oral bovine colostrum on the immune markers measured, so the mechanism usually claimed for it is not demonstrated. (Source 9)

• Meta-analysis, Low certainty.
• Size: 239 participants across 10 randomised controlled trials.
• Who: Athletes and physically active adults.
• How long: Varied across the included trials; not stated in the conclusions.
• Result: No significant effect on lymphocytes, neutrophils, serum IgG, serum IgA or salivary SIgA. The review states the effects on upper respiratory symptoms seen elsewhere must therefore act through mechanisms that remain unknown.
• Funding: Industry-linked: the article's funding statement names grant no. RG 3/2020 from the NUTRICIA Foundation.

This systematic review and meta-analysis shows that oral supplementation with BC has no significant effect on selected immunological outcomes including lymphocytes, neutrophils, serum IgG, serum IgA, and saliva SIgA in athletes and physically active people.

Where the evidence is mixed

The same review judged the underlying trials poorly reported and said its point estimates need confirmation in an adequately powered trial. (Source 5)

• Meta-analysis, Low certainty.
• Size: 152 participants across 5 trials.
• Who: Healthy adults in exercise training.
• How long: 8 to 12 weeks.
• Result: Four of five studies judged moderate or high overall risk of bias.
• Funding: No sponsors or sources of funding were used to prepare the review.

Due to incomplete reporting of study methods, four of the five studies were judged to have a moderate or high risk of overall bias.

A systematic review of 22 clinical trials in gastrointestinal disease found mixed results, with diarrhoea frequency often reduced but no change in its duration in most studies. (Source 10)

• Systematic review, Low certainty.
• Size: 22 clinical trials with 1427 patients.
• Who: Patients with gastrointestinal disease across mixed populations.
• How long: Varied across trials.
• Result: Diarrhoea frequency reduced in 15 of 20 interventional arms; abdominal pain improved in 4 arms and not in 5.
• Funding: not stated.

Diarrhea, the most frequently evaluated symptom (20 interventional arms), was decreased in frequency with BC supplementation in 15 of these arms. However, most studies reported no change in its duration.

Where the research disagrees

Whether oral bovine colostrum raises systemic IGF-1 enough to matter for doping control

• World Anti-Doping Agency, statement first published 2013, position: In 2013, the World Anti-Doping Agency (WADA) first published a statement that bovine colostrum contains (Source 4)
• Authors of a 2021 narrative review in Nutrients, narrative-review: These 2 studies are very much against the balance of evidence, however, with a large number of other studies showing no such increase. (Source 4)

How much

• Reference intake: No reference intake such as an RDA or AI exists for bovine colostrum, because it is a food ingredient and not an essential nutrient; what is reported in the literature is what trials gave, not a recommended intake. (Source 11)
• Upper limit: No tolerable upper intake level or acceptable daily intake has been set for bovine colostrum by the bodies we could reach. The World Anti-Doping Agency published a statement in 2013 advising against consumption by tested athletes, which is a doping-control position and not a toxicological limit. (Source 4)
• Studied: Buckley and colleagues gave 60 g/day of powdered bovine colostrum or a whey protein placebo for 8 weeks alongside three running sessions a week, as described in a review of sport and exercise studies. (Source 12)
• Studied: The pooled respiratory-symptom trials ran over an 8 to 12 week follow-up period in adults engaged in exercise training. (Source 5)

A common belief, and what the research shows

The belief: Colostrum's antibodies survive digestion and top up your own immune system.

What the research shows: Pooled randomised trials that measured immune markers directly did not show this. The 2020 meta-analysis reported that BC supplementation has no or a fairly low impact on improving the concentration of serum immunoglobulins (IgA, IgG), lymphocytes and neutrophils, and saliva immunoglobulin (IgA) in athletes and physically active participants. A 2021 review of the field also notes there is a gap of scientific knowledge on the mechanisms behind the respiratory findings.

Questions and answers

What is it?

Bovine colostrum is the first milk a cow makes just after calving, normally collected within the first two days and dried into a powder. It is far more concentrated than ordinary milk in protein, fat, immunoglobulins and lactoferrin. Supplements are sold as capsules or powders. (Source 11)

What does it do in the body?

In the cow, colostrum passes immune proteins and growth factors to the calf. In adult humans who swallow it, the proteins are digested like other food proteins, and trials that measured blood and saliva immune markers did not find meaningful changes. What the laboratory analyses show is that the powder is unusually rich in immunoglobulins and lactoferrin compared with ordinary milk. (Source 11)

Is it good or bad for you?

It is neither clearly good nor clearly bad. The most consistent human signal is fewer upper respiratory symptom days in people doing hard exercise training, from five small trials most of which were at moderate or high risk of bias. Against that, pooled immune-marker trials were null, and people with cow's milk allergy can react severely to it. (Source 5)

How do you get more of it?

Colostrum is only present in the first milk after birth, so ordinary dairy foods do not supply it. In studies it has been taken as a dried powder; one frequently cited trial gave 60 g a day for eight weeks against a whey protein placebo. This is what researchers gave volunteers, not a recommendation. (Source 12)

If it is harmful, what reduces it?

There is nothing to clear from the body, because colostrum is a food that is digested rather than something that accumulates. Reviews describe it as generally well tolerated, and the side effects reported in trials were mild and settled with time. For someone with cow's milk allergy, avoidance is the relevant step, since reactions can be severe. (Source 3)

Why might someone be low in it or missing it?

Nobody is deficient in colostrum. It is a stage of milk, not a nutrient the body requires, and adults simply do not consume it unless they buy a supplement. Ordinary mature milk contains far lower concentrations of the components colostrum is sold for. (Source 11)

Which whole foods contain it or feed it?

No ordinary whole food contains bovine colostrum. The only natural source is milk taken from a cow in the first day or two after she calves, which is not sold as a retail dairy product. Mature milk shares the same broad nutrient profile but at much lower concentrations of the bioactive fractions. (Source 11)

What happens if you do not have it?

Nothing happens. There is no deficiency state, because colostrum is not something the adult body needs. The question the trials actually ask is whether adding it changes outcomes, and the review that found the clearest effect says its estimates were imprecise and need confirmation. (Source 5)

How can you test for it?

There is no test for colostrum status, because there is no deficiency to measure. The only relevant testing in the literature we searched is allergy testing in people who react to it: specific IgE to milk proteins was measured in the anaphylaxis case report. Product IgG content is measured by manufacturers, not by clinicians. (Source 1)

We searched: Searched for colostrum biomarkers, colostrum status testing and colostrum diagnostic assays alongside the exercise, gut permeability, immune and gastrointestinal reviews; none of them describes a validated test of an individual's colostrum status.

References

1. Asian Pacific Journal of Allergy and Immunology. Anaphylaxis to cutaneous exposure to bovine colostrum based cream (abstract). 2019. PMID 29549703. Read the source
2. Asian Pacific Journal of Allergy and Immunology. Anaphylaxis to cutaneous exposure to bovine colostrum based cream (Case report section). 2019. PMID 29549703. Read the source
3. BMC Sports Science, Medicine and Rehabilitation. Bovine colostrum supplementation and upper respiratory symptoms during exercise training: a systematic review and meta-analysis of randomised controlled trials (safety passage). 2016. PMID 27462401, DOI 10.1186/s13102-016-0047-8. Read the source
4. Nutrients (MDPI). The Use of Bovine Colostrum in Sport and Exercise (IGF-1 and anti-doping passage). 2021. PMID 34073917, DOI 10.3390/nu13061789. Read the source
5. BMC Sports Science, Medicine and Rehabilitation. Bovine colostrum supplementation and upper respiratory symptoms during exercise training: a systematic review and meta-analysis of randomised controlled trials. 2016. PMID 27462401, DOI 10.1186/s13102-016-0047-8. Read the source
6. Nutrients (MDPI). A Systematic Review of the Influence of Bovine Colostrum Supplementation on Leaky Gut Syndrome in Athletes: Diagnostic Biomarkers and Future Directions. 2022. DOI 10.3390/nu14122512. Read the source
7. Nutrients (MDPI). The Use of Bovine Colostrum in Sport and Exercise (abstract). 2021. PMID 34073917, DOI 10.3390/nu13061789. Read the source
8. European Journal of Applied Physiology. Bovine colostrum supplementation does not affect plasma I-FABP concentrations following exercise in a hot and humid environment. 2017. DOI 10.1007/s00421-017-3743-5. Read the source
9. Nutrients (MDPI). Immunological Outcomes of Bovine Colostrum Supplementation in Trained and Physically Active People: A Systematic Review and Meta-Analysis. 2020. PMID 32276466, DOI 10.3390/nu12041023. Read the source
10. Systematic Reviews. Therapeutics effects of bovine colostrum applications on gastrointestinal diseases: a systematic review. 2024. PMID 38409162, DOI 10.1186/s13643-024-02489-1. Read the source
11. Nutrients (MDPI). The Use of Bovine Colostrum in Sport and Exercise (Section 1, Introduction: composition passage). 2021. PMID 34073917, DOI 10.3390/nu13061789. Read the source
12. Nutrients (MDPI). The Use of Bovine Colostrum in Sport and Exercise (Section 2.2: Buckley et al. trial protocol). 2021. PMID 34073917, DOI 10.3390/nu13061789. Read the source