not only sugar is dangerous for teeth

It’s widely recognized that sugar consumption leads to cavities, but recent research from Cornell University suggests that starchy carbohydrates might also contribute to dental decay, depending on one’s genetic makeup.

Key Findings

The study, published in the journal Microorganisms, investigated how the oral microbiome responds to starch intake. Researchers discovered that variations in the AMY1 gene, responsible for coding the salivary amylase enzyme, influence the composition of oral bacteria linked to dental health. Individuals with higher AMY1 copy numbers produce more salivary amylase, leading to more efficient starch breakdown in the mouth. This process provides additional sugars that certain bacteria, such as Streptococcus species, utilize, potentPrevious studies have associated AMY1 with cavities and periodontal disease. Poole, in prior studies, found that a high AMY1 copy number is associated with higher levels of the species Porphyromonas endodontalis, which is strongly associated with periodontitis and gum disease.

But how the salivary amylase enzyme interacts with its main substrate, starch, to alter the oral microbiome and increase disease risk was unclear.

“That’s what we wanted to know in this experiment,” Poole said. “What’s going on in the mouth if someone eats starch, and is the answer different if their copy number is high or if it’s low? What we found was that there are other bacteria involved in these processes and that the changes depended on AMY1.”ially increasing the risk of cavities.

Mechanisms & Biological Pathways

Salivary amylase initiates the digestion of dietary starches by breaking them down into simpler sugars directly in the mouth. The efficiency of this process is genetically determined by the number of AMY1 gene copies an individual possesses. A higher AMY1 copy number results in increased salivary amylase production, leading to rapid starch degradation. This enzymatic activity creates a sugar-rich environment that promotes the growth of acid-producing bacteria, which can erode tooth enamel and cause cavities.

Implications for Dental Professionals

Understanding the genetic factors influencing starch metabolism in the oral cavity offers valuable insights for dental practitioners. Personalized dental care strategies could be developed by considering a patient’s AMY1 gene copy number. For instance, individuals with higher AMY1 copies might benefit from more rigorous oral hygiene practices or dietary counseling to mitigate the increased risk of starch-induced cavities. This is confirmed by researchers themselves: “Most people have been warned that if you eat a bunch of sugar, make sure you brush your teeth,” said Angela Poole, senior author and assistant professor of molecular nutrition. “The takeaway finding here is that depending on your AMY1 copy number, you may want to be just as vigilant about brushing your teeth after eating those digestible starches.”

Study Overview

The research involved analyzing saliva samples from 31 participants in Ithaca, New York, with AMY1 copy numbers ranging from two to twenty.

The AMY1 copy number (CN) of participants ranged from 2–20. The CNs of the participants included in the study are shown in bold font. Microorganisms 2025/ Dorothy K.Superdock /13020461

The study examined how these variations affected the oral microbiome’s response to starch intake, revealing that higher AMY1 copy numbers were associated with increased populations of starch-metabolizing bacteria.

Each participant is represented by a column. Participant ID is on the x-axis. The color assignments differ between panels, and some are used more than once within each panel. (a) Proportions of the top 10 most prevalent genera in the biofilm samples are shown in different colors and any other genera present are collapsed in the category Others (striped bar). The top three genera were present in the same number of samples. (b) Proportions of the top 15 most prevalent genera in the saliva samples are shown in different colors and any other genera present are collapsed in the category Others (striped bar). All 15 genera were present in all the donors. * Prevotella para is an abbreviation for the genus Prevotella currently assigned to the family Paraprevotellaceae in the Greengenes database.

Data Visualization

To illustrate the relationship between AMY1 gene copy number, salivary amylase production, starch breakdown, and bacterial growth, the following flowchart provides a visual representation:

Conclusion

This study highlights the complex interplay between genetics, diet, and oral health. The findings suggest that individuals with higher AMY1 gene copy numbers, who produce more salivary amylase, may need to be more vigilant about their oral hygiene, especially after consuming starchy foods. These insights pave the way for personalized dental care approaches that consider genetic predispositions to optimize oral health outcomes.

Sources

ScienceDaily – Do starchy carbs cause cavities? – February 26, 2025
MDPI – The Impact of Human Salivary Amylase Gene Copy Number and Starch on Oral Biofilms – February 19, 2025

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Curatorial Yurij

Head of Content at Uniqa Dental As an expert in dental industry, my task is to tell in a simple and fascinating way about complex highly organized series of procedures for the benefit of practitioners.