Human breastmilk could help to prevent or treat COVID-19 not only in babies but in vulnerable adults too, according to a growing body of evidence.
A mounting library of scientific papers published since the onset of COVID-19 suggest that not only is the virus not spread from mother to baby through breastmilk, but that breastmilk may contain the key to neutralizing the virus all together.
Breastmilk and COVID-19 antibodies
It is well established that breastmilk contains antibodies to help babies’ immature immune systems fight off infections. Each antibody is highly targeted to pathogens in the lactating mother’s immediate surroundings; when the mother comes into contact with a disease-causing agent, she creates antibodies that are specifically designed to bind to that agent. These antibodies enter the breast milk and, when ingested, give passive immunity to the pathogen in question.
With the onset of the coronavirus pandemic, doctors therefore theorised that mothers who’d been infected with COVID-19 might make antibodies to the virus, which could be passed through breastmilk to protect their babies.
The research so far seems to back this up. Scientists at Amsterdam University say they have found multiple lines of evidence on the presence of a variety of antibodies that are effective against SARS-CoV-2 in the breastmilk of corona-affected women, with no such antibodies present in the controls.
“The mother’s body makes antibodies that can neutralize the coronavirus,” Professor Albert Heck, one of the researchers, said in a report by the University of Utrecht. “The fact that these are also found in breast milk is probably to protect their babies from the virus. Ideally, we will find a lot of very strong antibodies against COVID in the breast milk. Then that milk could be used to protect not only babies, but also vulnerable COVID patients.”
The Dutch researchers also found that these strong antibodies are not destroyed by the pasteurization process, meaning that breast milk could potentially be safely administered as “flavoured ice cubes” to fight the pandemic. “You want the antibodies to be in contact with the mucous membranes for as long as possible to really create that protective layer,” Britt van Keulen, a researcher at Amsterdam University’s medical centre, told The Times. “When you drink it, it disappears quickly. Our idea is to give it in the form of ice cubes, so it takes a little longer, there is longer contact with the mucous membranes to create that layer.”
It is the same principle as is being employed in plasma therapy - whereby antibodies in the blood plasma from recovered patients are being transferred to those who are sick – although scientists suggest that the antibodies in human breast milk are more durable and therefore possibly more effective than those in blood.
One such scientist is Rebecca Powell, a human milk immunologist and assistant professor at Icahn School of Medicine at Mount Sinai in New York City, who told The Wire that she imagines using breastmilk-derived antibodies in a respiratory therapy that patients could inhale — similar to an asthma treatment — sending antibodies right to the site of infection. “Secretory IgA antibodies, such as those in milk, are packaged by the body to be extra durable,” Powell says in The Wire report. “This lets them survive in environments such as the respiratory or digestive tract. In blood, the most common antibodies are a less durable type called IgG. This might make breast milk antibodies a more useful potential therapy than convalescent plasma.”
Could breastmilk pave the way to an antiviral drug?
But antibodies are not breastmilk’s only COVID-busting property.
Just like blood, human breastmilk is a living fluid containing good bacteria, antibodies, white blood cells, antimicrobials and proteins that offer protection against viruses and bad bacteria.
Breastmilk’s antiviral properties have been shown to work against both the HIV and Hepatitis C viruses, while its antimicrobial properties have been shown to strongly inhibit the growth of pathogenic bacteria, while allowing beneficial bacteria to grow (unlike antibiotics, which kill of all types of bacteria).
Chinese researchers set out to discover whether these powerful antimicrobial properties would also work against SARS-CoV-2, the virus which causes COVID-19.
After infecting breastmilk cells with the virus, the scientists at Beijing University of Chemical Technology found evidence that the whey protein in human breastmilk can effectively inhibit the coronavirus with 98% efficiency, by “blocking viral attachment, entry and even post-entry viral replication”.
Their research showed that whey protein from other species such as cow and goat also showed anti-coronavirus properties, although at a lower level.
The breastmilk samples were collected before the pandemic, meaning the donors would not have been infected with the virus and so would not have their own antibodies against the virus.
Interestingly, the main known antimicrobial components of breastmilk, such as Lactoferrin and IgA antibody, showed limited anti-coronavirus activity, indicating that other factors of breastmilk may play the important anti-coronavirus role.
The researchers hope that further research to identify the key antiviral factors at play in human breastmilk could play a part in antiviral drug development.
"We should invest more into breastmilk research"
The emerging research is very exciting, says Amy Vogelaar, a UAE-based lactation consultant, US-qualified midwife and co-founder of Love Parenting UAE, although she cautions that it is all very preliminary at the moment, and not yet peer-reviewed or tested on actual human subjects. “But it is completely common sense because we 100% know that breastmilk does protect children from so many familiar microbial infections and we know it does boost their immature immune system with mother's antibodies to whatever microbes she and baby have encountered.”
The study on whey is especially interesting, says Vogelaar “because they do believe that whey is one of many of the components of breastmilk which are health-promoting for babies, not just the obvious microbe-busters like Lactoferrin or Immunoglobulin cells.”
Vogelaar uses the example of oligosaccharides, sugars in breastmilk that were once believed to have no purpose because babies cannot actually digest them. “When I trained as a midwife I was taught that they just pass through babies and are not important. Then scientists figured out that beneficial gut microbes consume oligosaccharides, which is one reason why breastfed babies had such different microbiomes compared to formula-eating babies. They have since started adding oligosaccharides to formula milk.”
The health of the microbiome is relevant to COVID as well, she says, “because it seems to have such an impact on immune responses such as the cytokine storms which have contributed to mortality in so many COVID patients.
“Can components in breastmilk regulate the immune response to make it more beneficial and less destructive? We know it reduces obesity rates, which is a huge factor in COVID severity. What about breastmilk prevents obesity? We don't completely know.”
The increased scientific interest in the powerful properties of breastmilk is long overdue, says Vogelaar. “We know so little about breastmilk and how it works, which is such a waste. Breastmilk is a living substance with extremely well-established health promoting actions and components, and yet so many people still just see it as baby formula that comes from a more embarrassing package. I think the stuff is pure magic, but there is science to be had if we invest the time and resources.”
What this means for UAE mums
Although governments were initially cautious about guidelines around breastfeeding during the pandemic – and the US Centres for Disease Control and Prevention even initially recommended that an infected mother be separated from her baby – this has changed today. There is now a large body of evidence to suggest that the virus is not passed on through breastmilk, and the World Health Organisation (WHO) advises that even when mothers have COVID-19, “the benefits of breastfeeding substantially outweigh the potential risks for transmission.”
This is reinforced by the guidelines from the Dubai Health Authority, which recommends that a COVID-infected lactating mother speak to her doctor to determine whether to continue breastfeeding, to pump instead, or to postpone breastfeeding.
As far as the emerging research affects pregnant women and new mothers in the UAE, lactation consultant Amy Vogelaar says, “there is no better time than now to do whatever you can to breastfeed if that is what you wish to do - do what is necessary to get breastfeeding off to a good start and to continue breastfeeding as long as possible.
“While babies and toddlers have thus far been little affected by the virus, this may change at any time as the virus mutates, and of course some little ones have been more affected than others. And who knows what the next surprise pandemic will be?
“One of the wonderful silver linings I am observing from life with coronavirus is how many mothers are breastfeeding longer than they otherwise would have or expected to. Being in lockdown, working from home, and even mothers who lost their jobs (as unfortunate as that is) are all reporting more breastfeeding and longer breastfeeding. No better time than during a viral pandemic to do exactly that.”