Modern Diet Is Rotting Our Teeth

A study of the evolution of our teeth over the last 7,500 years shows that humans today have less diverse oral bacteria than historic populations, which scientists believe have contributed to chronic oral diseases in post-industrial lifestyles.

The researchers, from the University of Adelaide's Australian Centre for Ancient DNA (ACAD), the University of Aberdeen (Dept of Archeology), Scotland, and the Wellcome Trust Sanger Institute, Cambridge, England, published their study in Nature Genetics.

The authors say that analyzing the DNA of calcified bacteria on the teeth of humans throughout modern and ancient history "has shed light on the health consequences of the evolving diet and behavior from the Stone Age to modern day".

The scientists explained that there were negative changes in oral bacteria as our diets altered when we moved from being hunter-gatherers to farmers. Further changes were observed when humans started manufacturing food during the Industrial Revolution.

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Do The Health Benefits Of Berries Make It Past Your Mouth?

Research has suggested that compounds that give colorful fruits their rich hues, especially berries, promote health and might even prevent cancer. But for the first time, scientists have exposed extracts from numerous berries high in those pigments to human saliva to see just what kinds of health-promoting substances are likely to survive and be produced in the mouth.

It's too early to name the best berry for health promotion based on this initial work, but the researchers have discovered that two families of pigments that provide berries with their colors, called anthocyanins, are more susceptible to degradation in the mouth than are the other four classes of these pigments.

The Ohio State University study also showed that bacteria living in the mouth are responsible for most of the breakdown of these compounds that occurs in saliva. Researchers are investigating whether it's the berry pigments themselves, or instead the products of their degradation, that actually promote health.

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What Chimpanzees Can Teach Us About Tooth Development And Weaning

For more than two decades, scientists have relied on studies that linked juvenile primate tooth development with their weaning as a rough proxy for understanding similar developmental landmarks in the evolution of early humans. New research from Harvard, however, is challenging those conclusions by showing that tooth development and weaning aren't as closely related as previously thought.

Using a first-of-its-kind method, a team of researchers led by professors Tanya Smith and Richard Wrangham and Postdoctoral Fellow Zarin Machanda of Harvard's Department of Human Evolutionary Biology used high-resolution digital photographs of chimps in the wild to show that after the eruption of their first molar tooth, many juvenile chimps continue to nurse as much, if not more, than they had in the past. Their study is described in a paper in the Proceedings of the National Academy of Sciences.

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Vitamin D Linked To A 50 Percent Reduction In The Incidence Of Dental Caries

A new review of existing studies points toward a potential role for vitamin D in helping to prevent dental caries, or tooth decay.

The review, published in the December issue of Nutrition Reviews, encompassed 24 controlled clinical trials, spanning the 1920s to the 1980s, on approximately 3,000 children in several countries. These trials showed that vitamin D was associated with an approximately 50 percent reduction in the incidence of tooth decay.

"My main goal was to summarize the clinical trial database so that we could take a fresh look at this vitamin D question," said Dr. Philippe Hujoel of the University of Washington, who conducted the review.

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