Fact Check

Franks and Genes

Did a "study" really find that hot dog brands regularly contain human DNA and unlabeled meat substitutions?

Published Oct 26, 2015


[green-label]Claim:[/green-label]  A new study determined that hot dogs contain human DNA, and vegetarian versions contain meat.


[green-label]Example: [Collected via Twitter, October 2015][/green-label]

[green-label]Origins:[/green-label]   In late October 2015 multiple news sources reported on a "study" that purportedly documented the discovery of human DNA in several popular hot dog brands (and traces of meat in versions specifically marketed as "vegetarian"). The research on which the hot dog claims were based was alternately termed a "study," a "report," and "testing," with a private company called Clear Labs credited for the findings. (Incidentally, Clear Labs described their hot dog research as a "report," not a study.)

Among the news outlets that covered the claims was Britain's Daily Mail, who reported in a 26 October 2015 article headlines "HUMAN DNA found in popular hot dog and sausage brands and 10% of vegetarian varieties contain meat" that:

Human DNA has been found in two per cent of hot dogs and sausages, a major study of popular brands has revealed  Tests on 345 samples from different 75 brands also revealed ten per cent of vegetarian hot dogs contain meat. Out of the samples that tested positive for human genetic material (seven), 66 per cent (four) were vegetarian. The genetic testing analysis carried out by Clear Food, which looked at major brands and regional favorites being sold by ten retailers, did not specify which brands contained the human DNA or what caused the contamination.

Subsequent media coverage (including the Daily Mail's) sourced their information from Clear Foods' undated "The Hot Dog Report." In an embedded video, a Clear Foods representative described the company's claims:

The sum of Clear Food's findings appeared below the clip:

Of the 345 hot dogs and sausages Clear Food analyzed for this report, 14.4% were problematic in some way. Problems included substitutions and hygienic issues. Substitution occurs when ingredients are added that do not show up on the label. Hygienic issues occur when some sort of non-harmful contaminant is introduced to the hot dog, in most cases, human DNA. Here's what we found:

Substitution: We encountered a surprising number of substitutions or unexpected ingredients. We found evidence of meats not found on labels, an absence of ingredients advertised on labels, and meat in some vegetarian products.

Hygienic issues: Clear Food found human DNA in 2% of the samples, and in 2/3rds of the vegetarian samples.

We found evidence of chicken (in 10 samples), beef (in 4 samples), turkey (in 3 samples), and lamb (in 2 samples) in products that were not supposed to contain those ingredients.

Prior to the appearance of the "hot dog study," Clear Food was a relative unknown entity on social media. The company's first tweet was dated 22 October 2015; on that day (just a few days before the story went viral), Clear Food tweeted:

Kickstarter fund-raising effort described Clear Food's initiative thusly:

Clear Food is the authoritative online food guide for consumers. We are evaluating food at the molecular level to surface insights about our food that go far beyond the label. We can discover hidden additives, trace allergens, and unintended ingredients. Is your veggie burger really meat-free? Are your kids’ chicken nuggets 100% chicken like the label says? Is there wheat in your gluten-free pizza crust? Our advanced genomic analysis uncovers it all.

Missing from the bevy of articles about human DNA in hot dogs (and meat in veggie dogs) was any explanation about how Clear Food determined those percentages, under which conditions testing occurred, whether any independent entities confirmed or duplicated the claims, and the methodology by which Clear Food arrived at their overall conclusions. Information on the site and Clear Food's Kickstarter provided no information about their testing methods, the credibility of their research, or (most important) what the company's specific objective might be. The flurry of interest bore many similarities to an earlier report claiming California wine was contaminated with arsenic, peddled by a company that tested alcoholic beverages for "purity." Clear Food similarly touted its "Clear Score," aimed "to reward the brands with the highest average scores" based on criteria known only by Clear Food.

While the firm's claims were carried across major online news sites such CNN, MarketWatch, USA Today,, the Boston Globe and Sky News, it's not uncommon for multiple news sources to jump on a PR-based "study" with little to no independent verification of its claims. It's certainly not out of the realm of possibility hot dogs contain ingredients or adulterants folks might find unappetizing, but the claim about meat and human DNA adulterants did not originate with a "study" of any sort. Its findings lay solely with a brand new, private company who didn't disclose any details of their purported testing (or any proof that meaningful research was undertaken at all).

Clear Food didn't define the terms that they used to describe their findings, such as "genomic analysis technology" (unspecified) or "proprietary next-generation genomic sequencing workflow." Certain brands were deemed "problematic" at a rate of 14.4 percent, but again, no evidence was presented to substantiate that claim or establish the methodology as worthy of consideration. In short, while the results could bear out to some degree should testing be conducted in a scientific setting, Clear Food didn't appear to be an established laboratory presenting vetted data.

[green-label]Last updated:[/green-label] 26 October 2015

[green-label]Originally published:[/green-label] 26 October 2015

Kim LaCapria is a former writer for Snopes.

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