Lactoferrin Helps Protect Against Viruses

From the common cold and flu to newer threats, viral infections are a major cause of disease and death worldwide.

The protein lactoferrin has shown potent antiviral activity in preclinical and clinical (human) studies.

It attacks viruses at several points in their lifecycle, through various mechanisms.^1-4

While some lactoferrin is produced in the body, it can also be absorbed from oral intake, bolstering the body’s defenses.⁵

The best ways to avoid viral illnesses remain the standard precautions:

• Avoid contact with sick individuals.
• Wash your hands with soap and water frequently, for at least 20 seconds.
• If soap and water aren’t available, use a hand sanitizer with at least 60% alcohol.
• Avoid touching your eyes, nose, and mouth.
• Clean and disinfect frequently touched objects and surfaces.

Lactoferrin should not replace these tried-and-true preventive measures. However, it may provide an additional layer of defense to reduce the risk of contracting viral illnesses and to diminish their severity.

How Viruses Invade

Viruses are unlike other infectious agents.

For one thing, they cannot grow and reproduce on their own. They must hijack the controls of a host cell to survive and replicate. Also, they are tiny, far smaller than microscopic bacteria and fungi.⁶

Viruses are made up of miniscule packages of protein that surrounds genetic material. When they find a suitable host cell, they invade, then use that cell to produce new copies of the virus, which can go on to infect other cells.

The first step in this process occurs after the virus enters the body, often through the lining of respiratory airways or the digestive system. Viruses contain surface proteins that are able to recognize specific surface features of cells. This allows them to attach to cells and gain entry.

Once in the cell, the virus takes control of the cellular machinery to make copies of its genetic material and proteins that are then reassembled into new virus particles.

Lactoferrin helps protect by impeding the invasion and growth of viruses at multiple steps in this process.

A Constituent of Mother’s Milk

Lactoferrin is a protein found naturally in milk. It’s also produced in other bodily secretions, including tears and saliva, and by some immune system cells.⁴

Lactoferrin is found in highest amounts in colostrum, the first type of mother’s milk produced after a baby is born. It has remarkable powers to shield infants from infection before their own immune systems have fully developed.

In adults, it is an important component of defenses against infections.

In mucous, saliva, and other secretions, lactoferrin helps prevent pathogens from gaining entry through the linings of the oral cavity, nasal cavity, airways, and digestive system.

One unusual feature of lactoferrin is the diversity of viruses it can shield against. It has been shown to possess robust antiviral activity against different types of virus, from those that cause the common cold and flu, to HIV and hepatitis B and C viruses.⁴

Inhibiting Viruses from Entering Cells

The most important way lactoferrin defends against viral infections is by disrupting viruses from binding to cells. ^1-3,7

This can stop the virus in its tracks, before it has a chance to cause any problems. If the virus cannot attach to and enter cells, it cannot cause illness.

Lactoferrin does this in two different ways:

• It binds to the virus directly, blocking the viruses’ surface proteins’ ability to recognize binding sites on the surface of cell membranes.
• It binds to surface sites on the cell’s outer membrane that are targeted by viruses.

For example, a compound found on cell surfaces, called heparan sulfate, is a common target for various viruses.

Several studies have shown that lactoferrin binds to structures containing heparan sulfate, which can prevent viruses from recognizing and entering the cell.^7,8

Activating the Immune System

Lactoferrin also has indirect antiviral effects. It helps the body fight against a virus by activating immune defenses.

Lactoferrin activates natural killer cells and increases their number.^5,9 These immune cells are equipped to recognize abnormal cells, including those infected by viruses, and eliminate them. This can help prevent the spread of a virus in the body.

Lactoferrin also stimulates the production of other antiviral compounds, including the signaling proteins known as interferons.^2,4 One of the important ways that interferons promote immunity is to signal to surrounding cells that viruses are present, and help activate antiviral mechanisms to prevent growth and spread of those viruses.

Lactoferrin may also help block the ability of viruses to reproduce even if they’re already inside cells.^1,4

This helps limit the spread of the virus, potentially reducing the severity of the resulting illness.

Fighting Common Viral Illnesses

Lactoferrin has been shown, in laboratory, animal, and human studies, to have potent activity against a number of viruses.^{1-4,7,8,10-12}

This includes common viruses such as those that cause the common cold, the flu, and gastroenteritis (stomach flu).

There are several different types and strains of virus that cause these illnesses. Although the common cold and viral gastroenteritis are usually mild, influenza can prove deadly in young children, the elderly, and those with other health issues.

Some strains of the viruses that cause influenza are covered by annual flu vaccines, but many others are not. The extra protection afforded by lactoferrin could make a difference in helping to lessen the impact of these illnesses.

In one study, healthy women taking oral lactoferrin experienced a reduced onset of both common-cold-like and gastroenteritis symptoms.¹³

In other clinical studies, lactoferrin was effective for reducing the symptoms of viral gastroenteritis, including those caused by rotavirus and norovirus. Oral lactoferrin reduced the incidence and severity of the symptoms of these illnesses.⁴

People taking 100 mg of lactoferrin once a week had approximately 4-times more incidence of viral gastroenteritis compared to people who took it only six or seven days a week.⁴

Emerging Viral Threats

Coronaviruses of differing types have caused severe acute respiratory syndromes such as the SARS epidemic in Asia that killed over 700 people in 2003.¹⁴

This same family of SARS viruses emerged this year as the cause of COVID-19.

COVID-19 is too new to have been studied in depth, but it shares many features with other coronaviruses. These include the SARS and MERS viruses that caused previous highly serious infectious disease outbreaks.

Lactoferrin shows promise in helping to defend against SARS-type coronaviruses in at least two different ways.

In a 2011 study, lactoferrin was effective at blocking a model of a SARS-type coronavirus from entering host cells.⁷ It did this by preventing binding of viral elements to the heparan sulfate compounds on the surface of the target cells.

Given the lack of an effective vaccine or drug treatment for so many viral illnesses, lactoferrin is a promising new tool in the defense against viral illnesses.

Summary

Lactoferrin is a protein produced in milk, saliva, and other secretions.

Laboratory, animal, and clinical research demonstrates lactoferrin’s activity against a wide range of viruses, including those that cause the common cold and flu.

It works by helping to block viral invasion of cells and by amplifying the immune system’s power to eliminate viral infection from the body.

Taken orally, lactoferrin is readily absorbed and can play an important role in bolstering defenses against viral illnesses.

Material used with permission of Life Extension. All rights reserved.