Raw milk and raw milk products are 150 times more likely than their pasteurized counterparts to sicken those who consume them, according to a 13-year review published by the Centers for Disease Control and Prevention on Tuesday. States that permit raw milk sales also have more than twice as many illness outbreaks as states where raw milk is not sold.
The CDC study, published online in Emerging Infectious Diseases, reviewed dairy-related outbreaks between 1993 and 2006 in all 50 states, during which time the authors counted 121 dairy-related illness outbreaks resulting in 4,413 illnesses, 239 hospitalizations and three deaths.
Despite raw milk products accounting for approximately one percent of dairy production in the U.S., raw milk dairies were linked to 60 percent of those dairy-related outbreaks. In addition, 202 of the 239 hospitalizations (85 percent) resulted from raw milk outbreaks. Thirteen percent of patients from raw milk outbreaks were hospitalized, versus one percent of patients from pasteurized milk outbreaks.
Seventy-five percent of the raw milk outbreaks occurred in the 21 states where the sale of raw milk was legal at the study’s onset in 1993. Today, 30 states permit the sale of raw milk, while another seven are considering raw milk legislation changes this year.
The study found that individuals under the age of 20 accounted for 60 percent of those affected by raw milk outbreaks, compared with 23 percent associated with pasteurized products. Children were also more likely than adults to become seriously ill from pathogenic bacteria in raw milk.
The differences in illness severity between raw and pasteurized milk are largely due to the pathogens present in each: People sickened from raw milk typically ingest injurious bacteria — most commonly Salmonella or Campylobacter — whereas pasteurized milk outbreaks more often result from “relatively mild” pathogens such as norovirus, according to the CDC.
This is the first comprehensive federal-level update to raw milk statistics of this kind since 1998, when the Center for Food Safety and Applied Nutrition released a similar review of raw milk outbreaks spanning from 1973 to 1992. That study found that 46 raw milk outbreaks occurred during the review window, with 40 of them in states with legal raw milk sales.
At the time, the 1998 study concluded that “consumption of raw milk remains a preventable cause of foodborne illness.” Similarly, Tuesday’s CDC study suggested that “stronger restrictions and enforcement should be considered.”
“It’s really helpful to have these numbers updated as interest in raw milk increases through activist groups,” said Michele Jay-Russell, Ph.D., program manager of the Western Center for Food Safety at University of California Davis.
“I wouldn’t say the statistics are surprising, but it’s helpful to know that, unfortunately, things have not really changed since the last report,” she added. “Despite being in the 21st century, raw milk continues to make people sick.”
The study comes on the heels of one of the largest raw milk outbreaks in U.S. history. As of Tuesday, 77 people in four states have been sickened in a Campylobacter outbreak linked to raw milk from Your Family Cow dairy in Pennsylvania that began in late January. At least nine of the victims from that outbreak have been hospitalized.
Many of those who are ill in that outbreak are children. “Parents who have lived through the experience of watching their child fight for their life after drinking raw milk now say that it’s just not worth the risk,” said Dr. Barbara Mahon, co-author of the CDC study, in a news release.
Since January 2007, the end of the study’s review window, there have been at least 56 additional foodborne illness outbreaks associated with raw milk. Between 2010 and 2011, raw dairy products were linked to 21 outbreaks and 201 illnesses, while pasteurized dairy products caused two outbreaks and 39 illnesses.
According to Jay-Russell, nearly all instances of outbreaks from pasteurized dairy occur because of contamination after the pasteurization process.
This year, Indiana, New Jersey, Iowa, Idaho, New Hampshire, Kentucky and Wisconsin have all considered changes to their raw milk sales laws. The majority of the bills under review would either permit the sale of raw milk where currently illegal, or remove certain restrictions on its sale in states where it’s already permitted.
Federal law restricts the transport of raw milk across state lines for sale, though consumers are free to travel across state lines to purchase milk and take it home, and there is no law against consuming unpasteurized milk.
The push for loosened raw milk sales rules across many states runs counter to the best scientific recommendations the CDC and Food and Drug Administration can make based on the available data, Jay-Russell said. Many raw milk proponents argue that raw milk provides nutrients and numerous health benefits negated by the pasteurization process, while many food scientists say there’s no credible scientific evidence for any of those claims.
“It’s [the CDC and FDA’s] charge to look at the health statistics and inform the public and help policy makers create policy that makes sense,” Jay-Russell said. “But there’s a push-back. Some groups don’t want government influence over food, so it makes it a much more political debate than a scientific one.”