Unpasteurized Foods and Raw Honey

Sep 27, 2016 | Mayo Clinic Transplant Dietitian | @mayoclinictransplantdietitian | Comments (4)


Significant progress has been made over time in reducing the side effects of immunosuppressive therapy; however one side effect that remains is transplant recipients are more likely to develop infections, like those brought on by foodborne illness. Learning about food safety will empower you to shop, handle, prepare and consume foods in a way that reduces your chance of developing a foodborne illness. Let’s dive in to the topic of unpasteurized foods and raw honey.

Pasteurization is a heating process used in some foods to kill harmful bacteria like salmonella, E. coli and listeria. Some commons foods that are typically pasteurized include milk, juices, cheese and eggs. Consuming raw or unpasteurized milk, juices, cheese and eggs can pose extreme danger to transplant patients. A recent report from the Centers for Disease Control and Prevention (CDC) found that older adults, pregnant women, newborns and persons with compromised immune systems accounted for at least 90 percent of the listeriosis cases between 2009 and 2011. CDC reported that 21 percent of the people with listeriosis died.

While dairy foods and juices have a clear definition from the Food and Drug Administration for what pasteurized versus raw means, this is not the case for other foods like raw nuts and raw honey. “Pasteurization” of honey actually has no technical meaning, and heating honey doesn’t provide any food safety advantage. Producers may heat honey to keep it from crystalizing but there is nothing safer about honey calling itself “pasteurized” honey versus “raw” honey.

Therefore, you will not find any research or government advice indicating the need for immune compromised patients to use "pasteurized" honey. Foodborne pathogens actually do not survive in honey, so there is no additional risk in consuming it raw. Yeast can survive and grow in honey, but this fermentation will turn honey into mead, and a consumer would know this easily with visual inspection. Remember that infants under one year of age should never consume honey.

What you can do

Lower your risk of developing a foodborne illness by following these shopping tips:

  • Always check the “Sell-By” date before putting any food in your grocery cart.
  • Don’t buy food displayed in unsafe or unclean conditions.
  • Buy only pasteurized milk, soft cheeses made with pasteurized milk, and pasteurized or juices that have been otherwise treated to control harmful bacteria.
  • When buying eggs, purchase refrigerated shell eggs. If your recipe calls for raw eggs, purchase pasteurized, refrigerated liquid eggs.
  • Buy honey from a trusted source, and as with all foods, avoid honey with particulate matter that shouldn’t be there.


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This is a quote from the above article “ Foodborne pathogens actually do not survive in honey, so there is no additional risk in consuming it raw.”

I am confused by this remark. If there were no foodborne pathogens in honey, then there would be no risk to serving it to children under one year of age. Botulism spores do indeed reside in honey. There is no greater foodborne pathogen than botulism. Please explain!


To keely1, I asked a Mayo nutritionist about honey, she advised me to get the processed ones e.g. the ones sold in the bear shape dispensers.


Good morning
My understanding is that it has a lot to do with the packaging. Raw/ unpasteurized honey may not be packaged in a sterile environment. This can result in bacteria to develop and grow.


@keely1, @ajdo129 and @footballmum - I spoke to our dietetics expert on honey at Mayo Clinic and they said this: "There is a critical difference between botulinum spores and botulism toxin. Botulinum spores can and do exist in honey (and our general environment). The spores themselves are not necessarily problematic. Botulinum spores cannot be killed by heating honey at the temperatures used in commercial honey manufacturing. Honey is heated in commercial manufacturing to kill some yeasts (again, not pathogens) and to prevent crystallization (safe, but unwanted by most consumers). It is only when the botulinum spores are allowed to bloom into the botulism toxin that they become dangerous foodborne pathogens. This can happen in the setting of the pH of the infant gastrointestinal tract, which is not fully developed in the first year of life. This is why infants should not consume ANY honey, of any kind." If you have questions on what your children or your family should consume, it's best to contact your families' doctors or dietitians for specific information.

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