In the current era of the COVID-19 pandemic, we are bombarded by media coverage about the numbers of COVID-19 cases, how governments are handling the outbreak, ways to protect yourself from contracting coronavirus, and even potential remedies. One such claim floating around social media is that cow’s milk can protect you from coronavirus.
While milk can be a part of a healthy, varied diet, the claims that it can prevent or cure coronavirus are unfounded and potentially dangerous. The basis of these claims seems to be based on two immune-supporting components found in milk: lactoferrin and vitamin D.
Lactoferrin is a protein found in most secretions from mammals and is especially high in milk. This protein has some antimicrobial properties and research suggests that the transfer of lactoferrin from mother to baby via breastmilk might provide some immune support to the infant’s still-developing immune system. While concentrated lactoferrin is promoted as a dietary supplement in foods such as infant formulas, there is no evidence to suggest that the lactoferrin found in cow’s milk imparts any specific immune benefits to humans who drink it.
The second component of milk that is being suggested as beneficial is vitamin D. In the U.S., milk is fortified with vitamin D, a fat-soluble vitamin associated with many functions in the body, including growth and immune response. The claim that the vitamin D in milk somehow protects against coronavirus appears to be based on a meta-analysis published in 2017 in the British Medical Journal which found that vitamin D supplementation decreased the risk of acute respiratory infection. It’s important to note that this study investigated vitamin D supplementation at much higher doses than what is found in milk products. It also did not include COVID-19 in its definition of acute respiratory infection. In both cases, the suggestion seems to be that by consuming milk you are providing your body with specific immunity from the virus.
Immunity vs. Immune System
It is important to note that consuming foods which support your immune system does not mean that you have immunity from a specific bacteria or virus. Immunity means that your body has been exposed to specific pathogens and now has antibodies that know how to defeat the disease; this is how vaccines work. Strengthening your immune system on the other hand, does not mean that you will not become infected by a specific disease, but you might be better able to fight it off if you do contract it. As always, the best way to strengthen your immune system is to choose a healthy lifestyle, which includes eating a varied diet with plenty of fruits, vegetables, whole grains, dairy and proteins, drinking enough of water, getting adequate sleep, exercising, avoiding smoking and excessive stress.
Milk as Part of a Healthy Diet
While milk may not impart specific immune benefits to ward off COVID-19, it can be part of a healthy diet that will optimize your health and your body’s readiness to fight off infections of any kind.
In addition to the components listed above, milk also contains vitamin A, which helps with vision and skin health; calcium, which helps maintain bone strength and aids in the absorption of vitamin D; B vitamins important for energy metabolism and several essential minerals.
Milk is also a good source of protein. Whole milk can be a nutritious source of calories for young children (ages 1-2 years). The components listed above can also be found from other food sources such as fatty fish, liver, nuts, dark green leafy vegetables and fortified cereals. By choosing a varied diet with minimally processed foods you have the best opportunity to ensure you are consuming all essential nutrients in adequate quantities.
Shopping for Milk
When shopping for milk, consumers will find a “sell by” date stamped on the bottle. This is not the day the milk should be poured down the drain. This is the last date the grocery store can sell the bottle of milk. The sell-by date is designed to give consumers time to use the product at home before it goes bad. Typically, milk stays fresh for five-10 days past the sell-by date.
Factors for spoilage include exposure to light, heat, packaging type, and whether the container was opened or not. Storing the milk in the refrigerator (and not on the counter while the kids eat their cereal) and keeping the cap clean help to make the milk stay fresh longer. If milk has a sour smell or flavor, it isn’t necessarily going to make you sick; it just won’t be appetizing. Once opened, milk should be consumed within seven days.
If the milk shelf is empty in your grocery store, you might wonder to yourself if you should stop by a local dairy farm on the way home. Milk sold in the grocery store has been pasteurized, meaning it has been quickly heated for a specific amount of time to kill bacteria that can make people sick when the milk is consumed. Some farms pasteurize, bottle, and sell milk on-site directly to consumers. Visiting one of these farms is a great way to support your local dairy farmer. You can also support the Pennsylvania dairy industry when you buy milk at your grocery store. If the plant code on the milk container begins with the number 42, the milk has been bottled at a Pennsylvania plant.
In Pennsylvania, farms must have a permit to sell raw milk directly to a consumer, and most dairy farms do not hold that permit. “Raw” milk means that the milk has not gone through the pasteurization step to ensure safety. Farms that are permitted to sell raw milk to consumers are required to have their milk tested on a set schedule. Each batch of raw milk is not tested; testing gives a general idea of sanitation on the farm.
Individuals with weakened immune systems, young children, pregnant women, and senior citizens are at higher risk for becoming ill from eating or drinking contaminated food or drink.
The Best Defenses Against Coronavirus and False Information
The best defense against illness from COVID-19 is to follow the guidelines set forth by public health departments (Pennsylvania Department of Health, Centers for Disease Control and Prevention, World Health Organization). Wash your hands with soap and water often, use alcohol-based hand sanitizer when soap and water are not available, practice social distancing, wear a cloth face mask in areas where social distancing may be difficult (grocery store), and stay home when you aren’t feeling well.
For these claims and others that are sure to be spread by the well-intentioned, but misinformed, it is important to do your own research. Look at the source of the information. Reliable sources will come from a web address that ends in .gov, .edu or .int. If you see a post on social media and cannot trace it back to a reliable source, it is best to reach out to an expert before implementing the advice. The World Health Organization has a useful collection of Myth Busters specific to coronavirus. As always, you can reach out to your local Extension experts for advice on a variety of subjects.