DNA from tartar preserved on the teeth of ancient skeletons has revealed the consequences of changes in human diet and health from the Stone Age to modern day.
The ancient genetic record reveals the negative impact and changes farming and manufactured foods have had on the evolution of our oral bacteria.
An international team, led by the University of Adelaide’s Centre for Ancient DNA (ACAD), along with the University of Aberdeen and the Sanger Institute at Cambridge, has published the results in Nature Genetics.
Project co-leader Professor Keith Dobney, Sixth Century Chair of Human Palaeoecology at the University of Aberdeen said: “This provides us with a completely new window on how people lived and died in the past. Knowing the real genetic history of diseases we still suffer from today will help us better understand and even treat them.
“Being able to track them through time has huge implications for understanding the origins and history of human health – making the archaeological record extremely relevant and important to modern-day medics and geneticists.”
The researchers extracted DNA from tartar (calcified dental plaque) from 34 prehistoric northern European human skeletons, and traced changes in the nature of oral bacteria from the last hunter-gatherers, through the first farmers to later Bronze Age and Medieval times.
Study leader Professor Alan Cooper, Director of ACAD said: “This is the first record of how our evolution over the last 7,500 years has impacted the bacteria we carry with us and their important health consequences.
“Oral bacteria in modern man are markedly less diverse than historic populations and this is thought to contribute to chronic oral and other disease in post-industrial lifestyles.”
The development of farming around 10,000 years ago caused a major shift in human diet, resulting in a significant impact on our health. The same was true of the much more recent move to eating highly processed flour and sugar, both of which have contributed directly to health problems we see today such as tooth decay, diabetes and heart disease.
Professor Cooper added: “The composition of oral bacteria changed markedly with the introduction of farming, and again around 150 years ago. With the introduction of processed sugar and flour during the Industrial Revolution, we can see a dramatically decreased diversity in our oral bacteria, allowing domination by caries-causing strains. The modern mouth basically exists in a permanent disease state.”
Ironically, the introduction of sugar and carbohydrates contributed to the increase in dental plaque that now holds the vital information the scientists are studying.
Professor Dobney added: “Until now we’ve had to rely mainly on indirect evidence or historical documents to tell us what people ate and what kind of illnesses they suffered from in the past. But now we can directly extract genetic information on diet and health from the tartar on teeth – which is very abundant and well-preserved in the archaeological record – we have a totally new source of unique information stretching back thousands of years.”
Dr Julian Parkhill, co-author from the Wellcome Trust Sanger Institute said: “We have shown that genetic sequencing is not restricted to modern samples. Sequencing the oral microbiota of different populations, over the ages, from across the world will tell us how different diets have affected human health, opening a whole new area of research.
Professor Dobney and Professor Cooper have been working on the project for the past 17 years but only since 2007 has it been possible to carry out the research as a result of ACAD’s ultra-clean laboratories and strict decontamination and authentication protocols.
The research team is now expanding studies through time, and around the world, including other species such as Neanderthals.
- Nature Genetics (2013) doi:10.1038/ng.2536
22 October 2010 Elsevier
New Study in Journal of the American Dietetic Association
Periodontitis and tooth loss. Although traditional treatments concentrate on the, a common inflammatory disease in which gum tissue separates from teeth, leads to accumulation of bacteria and potential bone bacterial infection, more recent strategies target the inflammatory response. In an article in the November issue of the Journal of the American Dietetic Association , researchers from Harvard Medical School and Harvard School of Public Health found that dietary intake of polyunsaturated fatty acids (PUFAs) like fish oil, known to have anti-inflammatory properties, shows promise for the effective treatment and prevention of periodontitis.
“We found that n-3 fatty acid intake, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are inversely associated with periodontitis in the US population,” commented Asghar Z. Naqvi, MPH, MNS, Department of Medicine, Beth Israel Deaconess Medical Center. â€œTo date, the treatment of periodontitis has primarily involved mechanical cleaning and local antibiotic application. Thus, a dietary therapy, if effective, might be a less expensive and safer method for the prevention and treatment of periodontitis. Given the evidence indicating a role for n-3 fatty acids in other chronic inflammatory conditions, it is possible that treating periodontitis with n-3 fatty acids could have the added benefit of preventing other chronic diseases associated with inflammation, including stoke as well.â€
Using data from the National Health and Nutrition Examination Survey (NHANES), a nationally representative survey with a complex multistage, stratified probability sample, investigators found that dietary intake of the PUFAs DHA and (EPA) were associated with a decreased prevalence of periodontitis, although linolenic acid (LNA) did not show this association.
The study involved over 9,000 adults who participated in NHANES between 1999 and 2004 who had received dental examinations. Dietary DHA, EPA and LNA intake were estimated from 24-hour food recall interviews and data regarding supplementary use of PUFAs were captured as well. The NHANES study also collected extensive demographic, ethnic, educational and socioeconomic data, allowing the researchers to take other factors into consideration that might obscure the results.
The prevalence of periodontitis in the study sample was 8.2%. There was an approximately 20% reduction in periodontitis prevalence in those subjects who consumed the highest amount of dietary DHA. The reduction correlated with EPA was smaller, while the correlation to LNA was not statistically significant.
In an accompanying commentary, Elizabeth Krall Kaye, PhD, Professor, Boston University Henry M. Goldman
School of Dental Medicine, notes that three interesting results emerged from this study. One was that significantly reduced odds of periodontal disease were observed at relatively modest intakes of DHA and EPA. Another result of note was the suggestion of a threshold dose; that is, there seemed to be no further reduction in odds or periodontal disease conferred by intakes at the highest levels. Third, the results were no different when dietary plus supplemental intakes were examined. These findings are encouraging in that they suggest it may be possible to attain clinically meaningful benefits for periodontal disease at modest levels of n-3 fatty acid intakes from foods.
Foods that contain significant amounts of polyunsaturated fats include fatty fish like salmon, peanut butter, and nuts.
- Full bibliographic informationArticle: â€œn-3 Fatty Acids and Periodontitis in US Adultsâ€ by Asghar Z.
Naqvi, MPH, MNS; Catherine Buettner, MD, MPH; Russell S. Phillips, MD; Roger B. Davis, ScD; and Kenneth J. Mukamal, MD, MPH, MA.
Commentary: â€œn-3 Fatty Acid Intake and Periodontal Diseaseâ€ by Elizabeth Krall Kaye, PhD
Both appear in the Journal of the American Dietetic Association, Volume 110, Issue 11 (November 2010) published by Elsevier.
The U.S. Department of Health and Human Services (HHS) and the U.S. Environmental Protection Agency (EPA) have important new steps to ensure that standards and guidelines on fluoride in drinking water continue to provide the maximum protection to the American people to support good dental health, especially in children.
HHS is proposing that the recommended level of fluoride in drinking water can be set at the lowest end of the current optimal range to prevent tooth decay, and EPA is initiating review of the maximum amount of fluoride allowed in drinking water.
Agencies working together to maintain benefits of preventing tooth decay
while preventing excessive exposure
Community Water Fluoridation FAQ’s
Don’t eat the toothpaste
A study conducted between 1999 and 2004 by the federal Centers for Disease Control and Prevention found that 41% of children between the ages of 12 and 15 exhibited signs of dental fluorosis, a spotting or streaking on the teeth. That was up from nearly 23% found in a study from 1986 and 1987.
The CDC believes the increase is due mostly to children swallowing toothpaste with fluoride when they brush their teeth.
17/10/2010 10:36 GMT – University of Gothenburg –
New findings suggesting that bacteria in the mouth and/or intestine can affect the the outcome pathogenesis of atherosclerosis and lead to new treatment strategies, reveals research from the University of Gothenburg, Sweden.
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