Colostrum
Colostrum (also known colloquially as beestings,[1] bisnings[2] or first milk) is a form of milk produced by the mammary glands of mammals (including humans) in late pregnancy.
Most species will generate colostrum just prior to giving birth.
Colostrum contains antibodies to protect the newborn against disease, as
well as being lower in fat[3] and higher in protein than ordinary milk.
Human colostrum
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| Above is colostrum expressed on day 4 of lactation, and on the right is breastmilk expressed on day 8. Colostrum often has a yellow hue compared to breastmilk. |
Newborns have very immature digestive systems, and colostrum delivers its nutrients in a very concentrated low-volume form. It has a mild laxative effect, encouraging the passing of the baby's first stool, which is called meconium. This clears excess bilirubin,
a waste-product of dead red blood cells, which is produced in large
quantities at birth due to blood volume reduction, from the infant's
body and helps prevent jaundice. Colostrum is known to contain antibodies called immunoglobulins such as IgA, IgG, and IgM in mammals. IgA
is absorbed through the intestinal epithelium, travels through the
blood, and is secreted onto other Type 1 mucosal surfaces. These are the
major components of the adaptive immune system. Other immune components
of colostrum include the major components of the innate immune system,
such as lactoferrin,[4] lysozyme,[5] lactoperoxidase,[6] complement,[7] and proline-rich polypeptides (PRP).[8]
A number of cytokines (small messenger peptides that control the
functioning of the immune system) are found in colostrum as well,[9] including interleukins,[9] tumor necrosis factor,[10] chemokines,[11] and others. Colostrum also contains a number of growth factors, such as insulin-like growth factors I,[12] and II,[13] transforming growth factors alpha,[14] beta 1 and beta 2,[15][16] fibroblast growth factors,[17] epidermal growth factor,[18] granulocyte-macrophage-stimulating growth factor,[19] platelet-derived growth factor,[19] vascular endothelial growth factor,[20] and colony-stimulating factor-1.[21]
Colostrum is very rich in proteins, vitamin A, and sodium chloride,
but contains lower amounts of carbohydrates, lipids, and potassium than
normal milk. The most pertinent bioactive components in colostrum are
growth factors and antimicrobial factors. The antibodies in colostrum
provide passive immunity, while growth factors stimulate the development
of the gut. They are passed to the neonate and provide the first
protection against pathogens.
In animal husbandry
Colostrum is crucial for newborn farm animals. They receive no
passive transfer of immunity via the placenta before birth, so any
antibodies that they need have to be ingested. This oral transfer of
immunity can occur because the newborn's stomach is porous. This means
that large proteins (such as antibodies) can pass through the stomach
wall. The newborn animal must receive colostrum within 6 hours of being
born for maximal transfer of antibodies to occur. The stomach wall
remains somewhat open up to 24 hours of age, but transfer is more
limited.[22]
Livestock breeders commonly bank colostrum from their animals.
Colostrum can be stored frozen but it does lose some of its inherent
quality. Colostrum produced on a breeder's own premises is considered to
be superior to colostrum from other sources, because it is produced by
animals already exposed to (and, thus, making antibodies to) pathogens
occurring on the premises. A German study reported that multiparous mares produced on average a liter (quart) of colostrum containing 70 grams of IgG.[23]
Bovine colostrum is produced by cows for their newborn calves. In many dairy cow
herds the calves are not permitted to nurse; rather, they are fed
colostrum from a bottle or by stomach tube and later milk from a bottle
then a bucket.
Human consumption of bovine colostrum
Assertions that colostrum consumption is of human benefit are
questionable because most ingredients undergo digestion in the adult
stomach, including antibodies and all other proteins. Bovine colostrum
and its components are safe for human consumption, except in the context
of intolerance or allergy to lactose or other components. It shows
promise in the treatment or prevention of a variety of diseases.[24][25][26]
Bovine colostrum from pasture-fed cows contains immunoglobulins specific to many human pathogens, including Escherichia coli, Cryptosporidium parvum, Shigella flexneri, Salmonella, Staphylococcus,[27] and rotavirus
(which causes diarrhea in infants). Before the development of
antibiotics, colostrum was the main source of immunoglobulins used to
fight infections. In fact, when Albert Sabin made his first oral vaccine against polio, the immunoglobulin he used came from bovine colostrum.[28]
When antibiotics began to appear, interest in colostrum waned, but, now
that antibiotic-resistant strains of pathogens have developed, interest
is once again returning to natural alternatives to antibiotics, namely,
colostrum.[29]
Some athletes have used colostrum in an attempt to improve their performance[30] decrease recovery time,[31] and prevent sickness during peak performance levels.[32][33]
Thus, supplementation with bovine colostrum (20 g/d) in combination
with exercise training for 8 wk may increase bone-free lean body mass in
active men and women.[30][34]
Low IGF-1 levels may be associated with dementia in the very elderly, although causation has not been established.[35] People with eating disorders also have low levels of IGF-1 due to malnutrition,[36] as do obese individuals.[37] Supplementation with colostrum, which is rich in IGF-1, can be a useful part of a weight reduction program.[citation needed] Although IGF-1 is not absorbed intact by the body, it does stimulate the production of IGF-1 when taken as a supplement.[38]
Colostrum also has antioxidant components, such as lactoferrin[39] and hemopexin, which binds free heme in the body.[40]
Hyperimmune colostrum
Hyperimmune colostrum was an early attempt to boost the effectiveness
of natural bovine colostrum by immunizing cows with a specific pathogen
and then collecting the colostrum after the cow gave birth. This
initially appeared very promising as antibodies did appear towards the
specific pathogens or antigens that were used in the original challenge.
However, upon closer examination and comparison, it was found that IgG
levels in natural colostrum towards 19 specific human pathogens were
just as high as in hyperimmune colostrum, and natural colostrum nearly
always had higher antibody titers than did the hyperimmune version.[27] However, travelan, a drug used to prevent traveler's diarrhea is made using this method, and has been shown to prevent the disease in up to 90% of people.[41]
Proline-rich Polypeptides (PRP)
These small immune signaling peptides were independently discovered
in colostrum and other sources, such as blood plasma, in the United
States,[42] and Poland.[43] Hence they appear under various names in the literature, including Colostrinin,
CLN, transfer factor and PRP. They function as signal transducing
molecules that have the unique effect of modulating the immune system,
turning it up when the body comes under attack from pathogens or other
disease agents, and damping it when the danger is eliminated or
neutralized.[44]
At first thought to actually transfer immunity from one immune system
to another, it now appears that PRP simply stimulates cell-mediated
immunity.[45]
A 2006 study published in the Journal of Experimental Therapeutics and Oncology indicated that PRP may have an impact on the aging process by reducing the spontaneous or induced mutation frequency in the DNA of cells.[46]
Such DNA damage is implicated in the general process of aging. The
study, which was performed in both hamster and human cells, looked at
the impact of PRP on the frequency of defined DNA mutations in these
cells as they occur naturally and when induced by various known chemical
or physical agents. In cells stressed oxidatively, PRP reduced the
frequency of mutation induced by reactive oxygen species
(ROS) to nearly background levels in a dose-dependent manner. It is
suggested that the antimutagenic properties of PRP are achieved via
multiple mechanisms - by decreasing intracellular levels of ROS and so
preventing DNA damage and by increasing the efficiency of natural DNA
repair mechanisms.
PRP-rich preparations from bovine colostrum have shown some activity against various diseases including viral infections[47] of herpes viruses[48] and HIV,[49] as well as difficult to treat bacterial and fungal infections like Mycobacterium fortuitum[50] and Mycobacterium tuberculosis[51] (cause of tuberculosis), cryptosporidosis in AIDS patients,[52] and candida.[53] Also for various forms of cancer, such as Hodgkin's disease,[54] osteogenic sarcoma,[55] prostate cancer,[56]
and others. As an immune modulator, PRP is also effective in disease
states characterized by an overactive immune system, such as allergies,[57][58] asthma,[59] and autoimmune diseases.[60]
PRP has some effect in neurodegenerative diseases, especially Alzheimer's disease,[61] but has not yet shown longterm disease retarding effect.[62]
A placebo-controlled clinical trial in 106 people with Alzheimer’s over
30 weeks was completed in 2002 and the results appeared to demonstrate
efficacy in a significant proportion of patients treated.[63]
The results showed that approximately 40% of patients taking PRP were
stabilized or improved after 15 weeks of therapy, based on an Analysis
of Overall Response. 33% of patients continued to show stabilization or
improvement after 30 weeks of treatment, although levels of benefit were
slightly higher at the 15-week stage of the trial. The dosage regimen
used for the trial was 100 micrograms of PRP administered every second
day for three weeks followed by a two-week period without PRP.
There is one report of use in patients with intractable epilepsy.[64]
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