Food safety is often framed in simple terms: if bacteria are present, the food is unsafe. But a new analysis suggests the reality is more complicated and that striving for “zero detection” may not always make food safer.
A group of international researchers argues that modern food testing has become so sensitive that it can detect trace amounts of bacteria that pose little to no real health risk. In some cases, that can trigger recalls, food waste, and higher costs without clear benefits for public health.
“Zero risk doesn’t exist, and we shouldn’t be aiming for that either,” said Martin Wiedmann, a food safety expert at Cornell University and lead author of the study. He compares it to setting highway speed limits extremely low to eliminate all accidents. While it might reduce risk, it would create other problems.
The analysis, published in Frontiers in Science, highlights a key distinction that often gets lost outside of scientific circles: the difference between detecting a potential hazard and understanding actual risk.
For example, some food products are flagged if they test positive for bacteria like Listeria monocytogenes, regardless of how much is present. But risk depends on several factors, including the amount of bacteria, how the food is stored, and who is consuming it. Small traces may not be enough to cause illness, especially in healthy individuals.
When testing picks up these trace levels, the consequences can be significant. Products may be pulled from shelves. Food that is still safe to eat may be discarded. Manufacturers may increase packaging, processing, or storage measures that raise costs and energy use.
“A tremendous amount of food is wasted that would have been sufficiently safe to eat,” said co-author Sophia Johler of Ludwig Maximilian University of Munich.
The researchers argue that current systems often focus too heavily on whether a pathogen is present at all, rather than how likely it is to actually cause harm. They suggest shifting toward a more risk-based approach that considers real-world exposure and outcomes.
That doesn’t mean food safety should be taken lightly. Foodborne illness remains a serious global issue, causing an estimated 600 million cases and 420,000 deaths each year. Measures like proper cooking, refrigeration, and sanitation remain essential.
Instead, the authors say the goal should be balance. Overly strict responses to low-risk detections can divert attention and resources away from higher-risk situations where intervention matters more.
“There’s well-established evidence that focusing on end-product testing is generally ineffective to ensure safety,” said co-author Sriya Sunil. She notes that stronger results often come from improving processes earlier in the food system rather than relying on final testing alone.
For consumers, the takeaway is not that food safety concerns are overblown, but that they are more nuanced than they might appear. A positive test result does not automatically mean a food is dangerous, and zero detection is not always the most meaningful measure of safety.
In a food system balancing safety, cost, sustainability, and access, the question is not how to eliminate all risk, but how to manage it in ways that protect both public health and the food supply.
This research was conducted by an international group of scientists and published in Frontiers in Science. The study did not test a new product or intervention but reviewed existing evidence to evaluate how food safety standards are applied.