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Food Preservatives Delay How Fast Human Corpses Decompose?

Harper
Harper's Weekly/Public Domain

People have long wondered whether modern-day human corpses take longer to decompose due to the addition of preservatives in the food chain.

The claim dates back to at least 1991, when an article was published by the tabloid publication Weekly World News titled, "Junk-food keeps American corpses fresh as daisies!" The article claimed, "Funeral directors around the country report dead Americans aren't decaying in the grave — because they eat so much preservative-laden junk food!"

Other iterations of the notion have circulated online in the years since then, appearing on sites like Quora and Reddit, as well as the blog Modern Legends. (The blog's last publication occurred in October 2016.)

Cited in the aforementioned blog was a 2008 article published by the German weekly news magazine, Der Spiegel, that described research conducted by soil expert Rainer Horn from the Christian Albrecht University in Kiel, Germany. As the article wrote, Horn's team found, "Corpses are no longer decaying in many German cemeteries. Instead, the deceased become waxen, an uncanny process that has become so rampant it can no longer be ignored." 

A high moisture content in the subsoil combined with low temperatures and a lack of oxygen are the main culprits. These conditions transform the soft tissue of many bodies not into humus, but rather "a gray-white, paste-like, soft mass," says soil expert Rainer Horn from the Christian Albrecht University in Kiel, Germany.

As time passes, the remains of the departed coagulate to form "a hard, durable substance." When knocked with a spade, the wax-like bodies sound hollow.

This "grave wax" buildup has disturbed the natural cycle of decay -- and created a horror scenario for burial authorities. When bodies don't decompose, their graves can't be reused -- a common practice in Germany. Contrary to many other countries, where final resting places are traditionally maintained in perpetuity, Germany recycles cemetery plots after a period of 15 to 25 years. Experience has shown that the earthly remains of the deceased rot away almost entirely in this amount of time, but only under favorable soil conditions.

Nowhere in the article did Horn mention food preservatives as a possible cause delaying corpse decompsition. That notion was simply put forth as a theory — without corroborating evidence — in the 2012 Modern Legends post.

No Evidence to Support the Notion

There is no credible research that supports the theory that food preservatives delay decomposition, based on our research. It's unknown where, or how, the widely held misbelief took hold.

After reading the blog post at Snopes' recommendation, Nicholas Passalacqua, an associate professor and director of forensic anthropology at Western Carolina University, confirmed there is no evidence to suggest that preservatives in food affect decomposition at all — much less, the rate at which it occurs.

As other research has indicated, temperature and the makeup of cemeteries' soil, like its amount of moisture or ability to get oxygen, can delay decomposition. (We explain more about those types of environmental factors below.) 

Rather than seeing the impacts of people's diet on decomposition, the German researchers in 2008 were likely noticing slower speeds because of cemeteries' soil, Passalacqua told Snopes. Soil composition, specifically, affects air flow, water retention and fluidity, bacterial activity, and access to scavengers — all things that impact how slow or fast a corpse breaks down.

In the blog post, for example, the process of creating adipocere — an organic material that's a byproduct of decomposition — was analyzed. "It seems like cemeteries in Germany are seeing increased instances of bodies developing adipocere of the soft tissues," explained Passalacqua. "I'd argue that this is different from bodies decomposing normally at a slower rate."

Specifically, the 2008 research described a process that occurs after death called saponification. That's what happens when chemical changes transform body fat into adipocere, which has the consistency of semi-hard cheese and a soapy, waxy texture. Saponified tissues do not undergo the same processes as typical soft-tissue materials when they're decomposing.

Horn proposed in the 2008 article that cemeteries in Germany were not able to adequately rehabilitate soils in cemeteries due to their overuse over time.

These Factors Actually Affect Decomposition

Decomposition is largely impacted by the environment in which a body is left. Warmer temperatures, for example, accelerate decomposition, while cooler temperatures slow it. In addition to environmental conditions, what a body is buried in (or under) and its level of exposure to outside conditions, as well as the state of the body — such as whether it was burned or already in a state of decay — can also influence its rate of decomposition. Passalacqua said:

There are many things that affect the rate of decomposition. The primary factor that affects the rate of decomposition is temperature. The warmer it is, the more active bacteria and enzymes will be, and also the more active insect scavengers will be, because their metabolisms are correlated to ambient temperature. [...] However, that really depends on the soil matrix it is buried in and also assumes that the body is not buried in a way that significantly restricts its contact with the burial.

Similarly, if the body is placed in an oxygen-deprived environment, the rate of decomposition will be significantly slowed. 

And the encasement in which a body is laid to rest, such as a wooden or metal coffin versus a concrete vault, will also impact decomposition speed because it affects airflow and bacteria's access to the body. 

But if the remains have been treated with chemicals, like those used during embalming processes, the decomposition process will be drastically slowed. 

In the U.S., the National Funeral Directors Association estimated in 2022 that roughly 35% of dead bodies are buried, most of which are embalmed with toxic fluids to temporarily slow decomposition by up to a couple of years. Embalming does not altogether prevent decomposition but temporarily preserves soft tissue for the body to be sent home or preserved for a memorial service. 

Without embalming, a human body that is buried will typically reach skeletonization, the final stage of decomposition, within five years.  

5 Stages of Human Decomposition

Though there are many different ways forensic anthropologists observe and track human decomposition, the general steps for the process, according to Passalacqua, are: 

  • Self-digestion or fresh: Very early decomposition changes including Algor mortis, livor mortis, and rigor mortis.

  • Discoloration and bloat: Discoloration of tissues resulting from bacterial and enzymatic activity.

  • Active decay: Overall color changes to the soft tissues, including bloating of the body and colonization or consumption of soft tissues by insects.

  • Advanced decay: Purging of fluids from the body, exposure of skeletal elements, desiccation of soft tissues.

  • Skeletonization: Exposure of the skeleton with small amounts of soft tissue drying and desiccating on the remains.

Bottom Line

In sum, while preservatives added to food may negatively impact some people's health, there's no evidence that preservatives delay the decomposition of a body over time.

That claim has circulated for decades, in part because of a blog post that references a 2008 study of cemeteries in Germany. That study was real and indeed found bodies decomposing at a slower rate than a control group — though the reason for that difference was likely the composition of the cemetery's soil, not the deceased's food choices.

Sources:

Decomposition – The Forensics Library. http://aboutforensics.co.uk/decomposition/. Accessed 8 Sept. 2023.

Donation, Embalming/Organ. "Embalming Explained, Answers to Frequently Asked Questions." Funeral Consumers Alliance, https://funerals.org/?consumers=embalming-what-you-should-know. Accessed 8 Sept. 2023.

mischa. "Deadly Secrets—the Science of Decomposition." Curious, 21 Mar. 2016, https://www.science.org.au/curious/decomposition.

Mordhorst, Anneka, et al. "Changes in Soil Aeration and Soil Respiration of Simulated Grave Soils after Quicklime Application." Journal of Plant Nutrition and Soil Science, vol. 180, no. 2, Apr. 2017, pp. 153–64. DOI.org (Crossref), https://doi.org/10.1002/jpln.201600351.

Sambu, Saseendran, et al. "Toxicological and Teratogenic Effect of Various Food Additives: An Updated Review." BioMed Research International, vol. 2022, June 2022, p. 6829409. PubMed Central, https://doi.org/10.1155/2022/6829409.

Statistics. https://nfda.org/news/statistics. Accessed 8 Sept. 2023.

Thadeusz, Frank. "Germany's Tired Graveyards: A Rotten Way to Go?" Der Spiegel, 7 Jan. 2008. www.spiegel.de, https://www.spiegel.de/international/germany/germany-s-tired-graveyards-a-rotten-way-to-go-a-527134.html.

Viot. "Does Eating Preservatives Slow the Rate at Which Our Corpses Decompose?" R/Askscience, 23 Jan. 2015, www.reddit.com/r/askscience/comments/2tezjd/does_eating_preservatives_slow_the_rate_at_which/.

"Western Carolina University." Nicholas Passalacqua, https://www.wcu.edu/faculty/nvpassalacqua.aspx. Accessed 8 Sept. 2023.