Tag Archives: Processed foods

Child at DentistThe science is clear: processed foods are detrimental to our healthNow, new article in the April 2020 issue of Scientific American suggests that processed foods may undermine our health in ways we may not have previously considered, particularly our oral health.(1) 

 Teenagers and early adults regularly visit the dentist for removal of their third molars—often referred to as wisdom teethBefore this rite of passage, teens and smaller children undergo regular dental visits to fill cavities, remove calculus (tartar,) and, at a minimum, endure a thorough cleaning and polishing. 

Paleontologist and dental anthropologist Peter Ungar of the University of Arkansas says we have lost our way when it comes to dental hygiene and health. 

“Most other vertebrate creatures do not have the same dental problems that we do,” Ungar saysThey rarely have crooked teeth or cavities. Our fossil forebears did not have impacted wisdom teeth, and few appear to have gum disease.” 

Dr. Ungar attributes these maladies to the softer and more sugary foods that we eat almost from birth. Strained peas and apple sauce are poor substitutes for our ancestral diets. Instead, he argues, eating foods that are much less processed cause our jaws and teeth to grow strong, straight, and align properlyto an extent that allows enough space for all 32 of our teeth. Mechanical stress of our growing jaws is key to oral health. 

He also argues that the move away from ancestral diets has led to tooth decay—primarily exacerbated by high sugar content in processed foods, and the subsequent shift in the mouth’s bacterial biome. His view is supported by the work of Dr. Loren Cordain (2),(3) and others associated with The Paleo Diet®.(4)   

For example, Cordain notes, and Ungar supports the observation, that across the animal kingdom, dental problems are not the norm. Humans that pre-date terrestrial agriculture show few signs of dental problems, as is the case with small, isolated human populations today that retain hunting and gathering for food, with no access to westernized foods. 

More recently, the biggest jump in problems occurred during the Industrial Revolution, when access to highly refined foods and sucrose became the norm. Soft, sugary foods tipped the balance of oral health to disaster.

Tooth enamel is one of the hardest natural substances. Enamel is underlain by a tough but relatively flexible layer of dentin. Ungar emphasizes that we emerge at birth genetically preprogrammed to mechanically stress our teeth and jaws rather forcefully. Minimally processed foods that require vigorous chewing allow this natural process of oral stress to occur, much to a person’s oral well-being.

Ungar cited work by Robert Corruccini of Southern Illinois UniversityCorruccini, in a conversation with one of his students from nearby rural Kentucky, was surprised to learn that senior citizens in the student’s community had remarkably high oral health. A follow-up study by Corruccini showed the seniors had better bites than their younger children and grandchildren. The difference? Lifelong experience with lightly processed, hard-to-chew foods. 

The moral here is clear. Dental health professionals need to incorporate an evolutionary perspective in their overall strategies for oral health. 



  1. Ungar, P.S.  2020. The trouble with teeth. Scientific American 322(4):45-49. 
  2. Cordain L., Eaton S.B., Sebastian A., Mann N.Lindeberg S., Watkins B.A., et al. 2005. Origin and evolution of Western diet: health implications for the 21st century.  American Journal of Clinical Nutrition 81:341–54.  https://academic.oup.com/ajcn/article/81/2/341/4607411 
  3. Cordain, L.  2011. The paleo diet: lose weight and get healthy by eating the foods you were designed to eat. John Wiley and Sons, New York. 266pp. 
  4. Vuolo, S.  2016. Tooth decay and the paleo child. The Paleo Diet Newsletter.  https://thepaleodiet.com/tooth-decay-and-the-paleo-child/ 


One of the fundamental principles of The Paleo Diet® is the elimination of highly processed foods. These modern food items were not part of a natural hunter-gatherer diet, and the science continues to suggest they shouldn’t be part of ours. A recent study from two medical groups in France supports this idea, providing clear evidence that an ultra-processed diet should be avoided.

The research teams from the Centre de Recherche Epidémiologies et Statistique, Sorbonne Paris Cité and the Départment de Santé Publique, Hôpital Avicenne—both in Bobigny, France—examined how ultra-processed foods affect the overall risk of mortality in adults 45 years of age and older1.

Participants in these studies included 44,551 people from the larger, multi-year duration NutriNet-Santé Study2 (a total of 158,361 people), which included 73.1 percent women, with a mean age of 56.7 years.

Each participant kept records of his or her food choices using the NOVA food classification system.3 The system includes an ultra-processed category, defined as foods that contain ingredients with a technological or cosmetic purpose, rather than a purely nutritional purpose (e.g., preservatives, binders, texture enhancers, colors).

Ultra-processed foods accounted for an average of 14.4 percent of the total weight of food consumed by the participants, and 29.1 percent of the total energy. Additionally, consumption of these foods was most associated with people at the lower end of the age range (45 to 64), who had a lower income, lower educational attainment, were more likely to live alone, and who had a higher body-mass index and lower levels of physical activity.

It’s worth noting that this was a correlation study. Causal relationships can be elusive, even under strict controls. While additional direct studies are required to confirm the results, this study found a significant link between ultra-processed food consumption and “a higher risk of all-cause mortality.”

Recognizing that their study only showed a correlational relationship, the study authors proposed several hypotheses to explain the correlation:

Several hypotheses could explain the associations between increasing ultra-processed food consumption and higher mortality risk… Studies have documented that high ultra-processed food consumption was associated with unhealthy dietary patterns involving high intake of calories, fats, sugars, and salt. Those dietary factors could be associated with the development of noncommunicable diseases, which further lead to higher mortality risk. Studies have estimated that reducing saturated and trans fats, salt, and added sugar from the diet could present major advantages, such as preventing cardiovascular deaths.

These hypotheses and claims ring true to devotees of The Paleo Diet and provide further reassurance that conscientious eating patterns promote health and well-being. In particular, we should avoid overconsuming sugars and salt. Indeed, The Paleo Diet founder, Dr. Loren Cordain, has spent most of his career uncovering the perils of processed foods and the Westernized diet. His research emphasizes the benefits of simpler, less refined and less adulterated choices.4,5,6

A review of the aforementioned study and a follow-up analysis by CNN noted that 61 percent of the American diet consists of ultra-processed foods; in Canada it rises to 62 percent, and in the U.K. it’s 63 percent.7 Clearly, adoption of a diet that places an emphasis on simpler types of foods—and which specifically avoids ultra-processed foods—by the population of some developed countries, including the U.S., has a long way to go.



  1. Schnabel, L., E. Kesse-Guyot, B. Allés et al. 2019. Association between ultraprocessed food consumption and risk of mortality among middle-aged adults in France. JAMA Intern. Med. 179(4):490-498. doi:10.1001/jamainternmed.2018.7289
  2. Hercberg, S., K. Castebon, S. Czernichow et al. 2010. The NutriNet-Santé Study: a web-based prospective study on the relationship between nutrition and health and determinants of dietary patterns and nutritional status. BMC Public Health. 10(1):242. doi:10.1186/1471-2458-10-242
  3. Monteiro, C.A., G. Cannon, J.C. Moubarac et al. 2018. The UN Decade of Nutrition, the NOVA food classification and the trouble with ultra-processing. Public Health Nutr. 21(1):5-17. doi:10.1017/S1368980017000234
  4. Cordain, L., S.B. Eaton, A. Sebastian et al. 2005. Origins and evolution of the western diet: health implications for the 21st century. Amer. J. Clin. Nutr. 81(2):341–354. doi.org/10.1093/ajcn.81.2.341
  5. Aschwanden, C. 2015. The paleo diet: should you eat like a caveman? The Washington Post. https://www.washingtonpost.com/national/health-science/the-paleo-diet-should-you-eat-like-a-caveman/2015/01/12/4a985046-9678-11e4-8005 1924ede3e54a_story.html
  6. Karlsen, M. 2019. The paleo diet: what’s the story? Center for Nutrition Studies. https://nutritionstudies.org/paleo-diet-whats-story/
  7. Scutti, S. 2019. Avoiding ‘ultraprocessed’ foods may increase lifespan, study says. https://edition.cnn.com/2019/02/11/health/ultraprocessed-foods-early-death-study/index.html


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