Putting Milk Consumption Risks into Context

A pebble is almost nothing when compared to a mountain, just as the risk from this toxin is minor.

Even though people around the world drink milk every day without worry, there are certain risks. One risk comes from a particular toxin that has been linked to liver cancer, and just the thought of cancer can induce panic and avoidance. But it turns out that this risk from this toxin has been overestimated, while the detriment to nutrition may be underestimated. Aflatoxin M1 can be transferred into milk after cows and other mammals consume the more dangerous aflatoxin B1 produced by fungi on crops. Because aflatoxin B1 is a confirmed carcinogen, it has been assumed that aflatoxin M1 carried similar risks.

A journal article about these risks was published in April 2022 in The American Journal of Clinical Nutrition, and its title tells its conclusion: Aflatoxin M1 in milk does not contribute substantially to global liver cancer incidence. A research desk study on this topic was funded by the Feed the Future Innovation Lab for Livestock Systems and guided by author Felicia Wu from Michigan State University.

How Much?

An initial study published in 2021 by Dr. Wu and colleague Nikita Saha Turna characterized the incidence of aflatoxin M1 globally. It found that aflatoxin 1 levels in milk samples tested in several African nations exceeded standards set by the United States and European Union. Most countries have not set standards for tolerable daily intake of this toxin. Building on this research, Dr. Wu questioned how much disease in humans could be linked to drinking milk contaminated with aflatoxin M1. Applying epidemiological techniques to vast data sets Dr. Wu found something very interesting. Liver cancer was almost absent, and aflatoxin M1 could not be linked to more than 30 cases globally. This level makes it nearly 10,000 times less likely to contract cancer from drinking milk than getting hit by lightning!

How to Share the Story

This good news story could easily be lost during the seemingly endless bad news cycle of the COVID-19 pandemic. Plus, it would be especially important to inform countries in Eastern Africa and Eastern Europe because they have seen drops in demand for milk due to fears about aflatoxins.

MSU Professor Felicia Wu.

A multi-pronged approach was pursued to disseminate the findings. Dr. Wu’s co-Principal Investigator of this study was Arie Havelaar from the University of Florida, who is also the Innovation Lab’s co-leader for the Area of Inquiry for Human Health, Food Safety, Diets & Nutrition. With the Innovation Lab Director, they produced a research brief that targeted policymakers with some technical understanding. This brief was emailed directly to certain stakeholders and distributed widely as part of a blog post, published on April 29, 2022. This post from the University of Florida provided for optimal ease of sharing through the university’s networks and across social media. To round out this outreach effort, two products were pitched to the public at large: a one-page infographic, and a webinar held on May 10, 2022. More than 50 people attended the live webinar, and more than 100 have viewed the recording shared on YouTube. A special session to relay the findings to the Rwanda Standards Board has led to a review of the milk aflatoxin action levels in Rwanda.

Next Steps

Dr. Wu is continuing this line of research with a new project in Ethiopia: Aflatoxin M1 Health Risks vs. Benefits of Dairy Consumption in Ethiopian Children: An Epidemio­logical Trial and Risk-Benefit Analysis. This project seeks to understand how aflatoxin M1 affects the growth of children and subsequently to inform policies about their consumption of milk.



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Posted: December 2, 2022

Category: Livestock, Pests & Disease, UF/IFAS Research
Tags: Aflatoxin, Disease, Global, Human Health, Milk

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