Dr. Sharon DeWitte has co-authored an article published in the Annals of Human Biology that has won the Nick Norgan Award. The Nick Norgan Award is for the best article selected from high-impact articles published in the journal in the previous year. The title of the article is "A new method for investigating the relationship between diet and mortality: hazard analysis using dietary isotopes". For the study, researchers examined skeletons of people who lived in the 1st - 5th century AD and were buried in Roman cemeteries in Britain.
The goal of the study was to test if there is a relationship between isotope levels in a person's body and the person's mortality risk (i.e., risk of dying). What is an isotope? First, understand that everything in the universe, including the human body, is made up of matter. Matter is made up of elements (e.g., oxygen). An atom is the physical and chemical structure of an element, and each element has a specifically sized atom. An isotope is a heavier version of an element's main type of atom.
The article focuses on the isotopes for the elements carbon and nitrogen. These isotopes relate to how much of a person's diet includes animal-based proteins. Higher isotope levels may suggest that a person had more meat in their diet. However, it may also suggest that the person was starving. When a person starves, their body uses the proteins from their muscles as food to survive. Researchers concluded that a person with a high isotope level who died younger was more likely to be malnourished and so more likely to have a higher mortality risk. In contrast, they concluded that a person with a high isotope level who died older was more likely to have had meat - not from their muscles - as a main part of their diet and so more likely to have had a lower mortality risk.
One limitation of the study is that isotope data is based on the eating habits of a person over a long period of time. Dr. DeWitte notes, "We don't actually know the meals that people were eating. You don't know how [their diet] might have changed over the short term within [their] lifetime. Maybe people had access to different foods based on certain factors that change rapidly within the life course". Therefore, in research, it's important to have data from experiments using different methods or looking at a topic from a different perspective. More data from diverse experiments can create more evidence for and knowledge about a topic.
When people study the same topic in different ways, they may end up with different results. "No research project is ever the final word on anything...[W]hen I see contradictions or conflicting results, I see that as a motivation to do further work," says Dr. DeWitte. In the past, she has contacted researchers who've studied the same topic as her and had different results. By contacting each other, researchers with opposing results can learn or try to figure out why the results differed. This new knowledge helps them better understand the topic. In the case mentioned, Dr. DeWitte may even end up collaborating with the researchers she contacted.
The isotope study is novel because it uses Dr. DeWitte's unique data analysis methods to compare dietary isotope data to mortality risk. Looking ahead, hopefully, other researchers will use her and other methods to create a better understanding of the link between these isotopes and death. As her study article concludes, such understanding is important since increasing knowledge about the relationship between diet and health.
Read the full article for more details.
Matter, elements, and atoms. (n.d.). Khan Academy. Retrieved April 14, 2021, from https://www.khanacademy.org/science/ap-biology/chemistry-of-life/elements-of-life/a/matter-elements-atoms-article