A growing bird flu epidemic has spread through American cattle and poultry, sparking harsh warnings from federal health and food safety regulators to avoid raw milk and eggs.
It’s all coming amid a surge in the number of people drinking raw, non-pasteurized milk, a trend that could lead to dangers not limited to bird flu.
Because it is not pasteurized like the milk normally sold in grocery stores, raw milk is not heat-treated to kill any potential pathogens.
Experts warn that without pasteurization, viruses like E. coli, salmonella, listeria and the current bird flu could infect vulnerable populations.
University of Wisconsin–Madison food science professor John Lucey told The Hill that the avian flu outbreak among cattle is a “serious concern” for public health because of the raw milk risk.
The Centers for Disease Control and Prevention (CDC) and Food and Drug Administration have repeatedly warned in recent weeks to avoid raw dairy products due to the bird flu outbreak.
The urgency in the CDC warnings is connected to a rise in the sales of raw milk.
Despite the warnings from federal regulators and food scientists, sales for raw milk have actually increased since the bird flu epidemic first appeared in the U.S.
Sales for raw dairy products have gone up by at least 25 percent compared to last year, according to the market research firm NielsenIQ.
While it is federally illegal to trade raw milk across state lines, a number of states have loosened restrictions on raw milk sales within their borders in recent years.
Raw dairy product sales are legal in 14 states and have only limited restrictions in more than two dozen others, according to the raw milk advocacy group the Campaign for Real Milk.
Thousands of farms and individual retailers sell raw dairy products in the U.S., and their offerings are easily searchable online through sites set up by raw milk enthusiasts.
Advocates claim that raw milk is more healthy than its pasteurized alternative, preventing illness or even lengthening lifespan, though there is no scientific backing for the claims.
Critics are dubious.
“I’ve been doing research on dairy products and milk for 20-plus years,” Lucey said. “In my field, nobody gives credence to these fantastic claims.”
“These claims — I’m a chemist by trade — just make no sense whatsoever on any kind of science or chemistry basis,” he continued.
Lucey compared the requirement to pasteurize milk to the standard that any piece of chicken should be cooked through before eating.
“There can be pathogens that can cause severe illnesses from eating or consuming raw milk just like raw meat,” he said.
Milk carries a high viral load of the current bird flu, Lucey said, meaning that there is a sizable risk that milk from a cow infected by bird flu could be sold on the market. He hypothesized that the current strain of avian flu could have receptors that are especially effective in cattle mammary glands, though study of the current outbreak is only in its early stages.
The U.S. Department of Agriculture (USDA) has confirmed that there are outbreaks in 51 cattle herds across the country in states including Michigan, New Mexico, North Carolina, Kansas, Colorado, Idaho, Ohio, South Dakota and Texas.
There have been no cases of bird flu in humans tied to raw milk, but the risk is present, Lucey said. Two people have been infected with the bird flu in the U.S. in connection with the current outbreak.
A Johns Hopkins University analysis of studies on raw milk safety found that more than half of milk-related foodborne illness outbreaks could be traced to raw milk, despite only about 3.5 percent of the population consuming it as of 2015.
As for raw milk, Lucey said the issue remains serious because the people who drink dairy milk the most, children and pregnant women, are inherently more vulnerable to food-based illness.
“If they drink contaminated milk,” Lucey said of the vulnerable groups, “they’re the ones that can have long-lasting effects.”
“Fortunately, we already have a good solution to this virus: pasteurization,” he continued. “It’s 100 percent effective at killing pathogens. If that was not the case, then we would be in a very different situation.”