Scientists studied the bones of people who lived in Brazil thousands of years ago to figure out what they ate. By looking at special markers in bone and tooth samples, researchers discovered that ancient shellmound communities ate a mix of ocean fish, freshwater fish, and land animals. The study found that different groups of people—and even different ages—ate somewhat different diets. This research helps us understand how ancient communities survived and whether everyone in a group ate the same foods or if there were differences based on age or social groups.

The Quick Take

  • What they studied: What did people eat in ancient Brazil 5,600 to 7,000 years ago? Scientists looked at chemical markers in old bones and teeth to figure out if everyone in a community ate the same foods or if diets varied by person.
  • Who participated: The study examined 88 bone samples and 5 tooth samples from people buried at two ancient shellmound sites in southeastern Brazil called Piaçaguera and Moraes. They also included information from other similar sites in Brazil.
  • Key finding: People at these ancient sites ate a balanced mix of foods: ocean fish made up about 30-50% of their diet, while land animals provided 16-45%. Younger people ate more freshwater fish than older people at one site, and different burial groups showed slight differences in their food choices.
  • What it means for you: This research helps us understand how ancient people adapted to their environment and survived. It shows that even thousands of years ago, communities had diverse diets and that age may have affected what people ate. This doesn’t directly apply to modern nutrition but helps us appreciate human dietary flexibility throughout history.

The Research Details

Scientists collected tiny samples of bone and tooth material from skeletons found at two ancient Brazilian sites. They measured special chemical markers (called isotopes) in these samples—think of these markers like fingerprints that show what foods were eaten. The markers for carbon and nitrogen in bones and teeth reveal whether someone ate mostly ocean foods, freshwater foods, or land animals.

To make sense of all this data, the researchers used a special computer program called a Bayesian Mixing Model. This program is like a detective tool that looks at all the chemical clues and figures out the most likely combination of foods that would create those exact chemical patterns. The researchers improved this tool to handle both bone and tooth samples together without creating problems with the analysis.

The team also used radiocarbon dating—a method that measures radioactive carbon in old materials to figure out exactly how old they are—to determine when people lived at these sites.

This approach is important because bones and teeth preserve chemical information about diet for thousands of years. By studying these markers, scientists can answer questions that would be impossible to answer otherwise: What did people really eat? Did everyone eat the same foods? Did diet change based on age or social position? This method is more reliable than just looking at leftover food scraps because it shows what people actually consumed and absorbed into their bodies.

The study is strong because it combined multiple types of evidence: bone samples, tooth samples, and data from other similar sites. The researchers used advanced statistical methods to ensure their conclusions were solid. They also carefully checked their results against what archaeologists know about these sites from other evidence like tools and settlement patterns. The study included 88 samples, which is a reasonable number for this type of ancient research. One limitation is that tooth samples were limited (only 5), which means conclusions about individual variation are based mainly on bone samples.

What the Results Show

At the Piaçaguera site, people got about 30-50% of their calories from ocean fish, showing they were skilled at fishing and had good access to coastal resources. At the Moraes site, land animals were more important, providing 16-45% of the diet. This difference likely reflects the different environments around each site and what resources were easiest to access.

The researchers found that the two burial groups at Piaçaguera—people buried in different locations at the same site—showed slightly different eating patterns. However, radiocarbon dating proved these groups lived at the same time, not in different time periods. This suggests that diet differences were based on personal choice, family tradition, or social position rather than time period.

At the Moraes site, younger people (subadults) ate noticeably more freshwater fish than older adults. This could mean that younger people had different food preferences, or that adults gave them different foods, or that younger people spent more time fishing in rivers while adults hunted on land.

Overall, the results show that these ancient communities had diverse, flexible diets and weren’t dependent on just one food source. This flexibility likely helped them survive in changing environments.

The study confirmed that the improved computer model the researchers created was effective and reliable. This tool could be useful for other scientists studying ancient diets at different archaeological sites. The research also showed that combining bone and tooth data gives a more complete picture than using just one type of sample. The findings support the idea that ancient Brazilian shellmound communities were sophisticated in their food gathering, managing both ocean and land resources.

Previous studies of these same sites had suggested that shellmound people relied heavily on ocean resources, but this new research shows a more balanced picture. The findings fit with what other archaeologists have discovered at similar sites in South America—that coastal communities were flexible and ate whatever resources were available. The study builds on earlier isotopic research but uses better methods and more samples, making the conclusions stronger.

The study has some important limitations to consider. The tooth samples were very limited (only 5), so conclusions about individual variation are based mainly on bones. The researchers only studied two main sites in detail, though they included data from other sites. Isotopic analysis shows general patterns but can’t tell us about specific meals or seasonal changes in diet. The study also can’t explain why diet differences existed—whether they were based on age, gender, social status, or personal choice. Finally, the ancient sites are thousands of years old, so we can’t directly observe how people actually lived and ate.

The Bottom Line

This research doesn’t provide direct health recommendations for modern people, as it’s about ancient history. However, it does suggest that humans have always thrived on diverse diets combining multiple food sources. For those interested in archaeology or anthropology, this study demonstrates the value of using scientific methods to understand the past. Confidence level: High for the specific findings about these two sites; Moderate for broader conclusions about all ancient Brazilian communities.

Archaeologists, anthropologists, and students of human history should find this research valuable. Museum professionals and educators can use these findings to better explain how ancient people lived. The general public interested in how humans adapted to different environments throughout history will appreciate these insights. This research is NOT medical advice and doesn’t apply to modern diet choices.

This research describes events from 5,600 to 7,000 years ago. The findings help us understand long-term human adaptation over thousands of years, not changes that happen in days or weeks.

Want to Apply This Research?

  • While this ancient research doesn’t apply to modern tracking, users interested in archaeology could track their learning: Record which ancient sites they’ve learned about, what foods ancient people ate in different regions, and how diet varied by geography and time period.
  • Users could use this research to inspire exploration of local indigenous food traditions and historical diets in their own region. They might research what foods were traditionally eaten in their area before modern agriculture and consider trying traditional recipes or visiting archaeological museums.
  • For educational purposes, users could maintain a journal tracking their learning about human dietary history across different time periods and cultures, noting how environmental factors influenced food choices in different ancient communities.

This article describes archaeological research about ancient diets and is provided for educational and historical interest only. It does not constitute medical advice, nutritional guidance, or health recommendations. The findings describe what people ate thousands of years ago and should not be interpreted as suggestions for modern diet or health decisions. If you have questions about your own nutrition or health, please consult with a qualified healthcare provider or registered dietitian. This research is based on scientific analysis of archaeological remains and represents one study’s findings; individual results and interpretations may vary.