Scientists found evidence that adzuki beans were grown in China thousands of years earlier than anyone thought. By studying bean remains from an ancient site in Shandong, China, researchers discovered that people were farming adzuki beans between 9,000 and 8,000 years ago. This discovery pushes back the known history of adzuki bean farming by at least 4,000 years. The study also shows that different regions of East Asia developed their own ways of growing and selecting adzuki beans over time, creating the varieties we see today. This research helps us understand how ancient people in Asia developed agriculture and selected plants that would become important food sources.

The Quick Take

  • What they studied: When and how adzuki beans were first grown and domesticated in East Asia by examining ancient bean remains from archaeological sites
  • Who participated: Researchers analyzed bean samples from 41 different archaeological sites across East Asia, with the main discovery coming from the Xiaogao site in Shandong, China
  • Key finding: Adzuki beans were being grown in China 8,985-8,645 years ago and again 8,032-7,939 years ago, which is at least 4,000 years earlier than previously documented evidence
  • What it means for you: This research helps us understand the deep history of agriculture in Asia and how ancient farmers developed the crops we eat today. While this is primarily historical knowledge, it shows how humans have been selecting and improving plants for thousands of years.

The Research Details

Scientists examined physical remains of adzuki beans found at archaeological dig sites across East Asia, focusing on a site called Xiaogao in Shandong, China. They used special dating techniques to determine exactly how old the beans were—between 9,000 and 8,000 years old. The researchers then measured and compared beans from 41 different archaeological sites to see how bean sizes changed over time and across different regions. By looking at these patterns, they could understand how different groups of people in different areas gradually changed the beans through selective farming practices.

This approach is important because it uses actual physical evidence from the ground rather than just written records or stories. By examining real ancient beans and measuring how they changed over thousands of years, scientists can see exactly how people domesticated plants and developed agriculture. This helps us understand one of the most important developments in human history—the shift from hunting and gathering to farming.

This research was published in the Proceedings of the National Academy of Sciences, one of the most respected scientific journals in the world. The study used direct dating methods on the actual bean remains, which is more reliable than estimating age indirectly. The researchers examined beans from many sites across a wide geographic area, which strengthens their conclusions about regional differences in how beans were grown.

What the Results Show

The most important discovery is that adzuki beans were being grown at the Xiaogao site in Shandong, China between 8,985-8,645 years ago and again between 8,032-7,939 years ago. This is significantly older than any previously confirmed evidence of adzuki bean farming. The beans were grown alongside other crops like millet, rice, and soybeans, showing that ancient farmers were already practicing a diverse farming system with multiple crops. When researchers looked at beans from 41 sites across East Asia and measured their sizes, they found that beans generally got larger over time. However, different regions showed different patterns—beans in the Yellow River region developed differently than beans in Japan during the Jomon period, suggesting that each region had its own farming traditions and preferences.

The research reveals that adzuki bean domestication was not a single event in one place, but rather a complex process that happened differently in different regions. The differences in bean sizes between regions suggest that people in different areas had different reasons for selecting certain beans—possibly based on what foods they preferred to eat or what grew best in their local environment. This shows that ancient farmers were actively choosing which plants to grow based on their own needs and preferences.

This discovery extends the known history of adzuki bean farming by at least 4,000 years compared to previously published directly dated evidence. It confirms that adzuki beans were part of early agricultural systems in East Asia much earlier than previously thought. The findings fit with what we know about early agriculture in China, showing that the Yellow River region was indeed a center of crop domestication during the Early Neolithic period.

The study focuses on archaeological remains, which means we can only learn what the physical beans tell us. We cannot know exactly why ancient farmers chose to grow certain beans or what their complete farming practices were. The sample sizes from individual sites may be small, so some conclusions about regional differences are based on combining data from many sites rather than from large samples at single locations. Additionally, some regions may have better archaeological records than others, which could affect our understanding of where and when beans were first grown.

The Bottom Line

This research is primarily of historical and scientific interest rather than providing direct health or nutrition recommendations. However, it demonstrates that adzuki beans have been valued as a food source for thousands of years, suggesting they are a well-established and reliable crop. If you’re interested in traditional or heritage foods, adzuki beans represent a crop with deep historical roots in Asian agriculture. (Confidence level: High for historical facts; not applicable for health recommendations)

This research matters most to archaeologists, historians, and people interested in the history of agriculture and human civilization. It’s also relevant to farmers and agricultural scientists studying crop domestication and how plants change over time. Anyone interested in the origins of Asian cuisine and traditional foods may find this fascinating. This is not medical or nutritional advice and should not be used to make health decisions.

This research describes events that occurred 8,000-9,000 years ago. There are no immediate timelines for modern applications, as this is historical research rather than a study of current health or nutrition effects.

Want to Apply This Research?

  • If using a food tracking app, users could log adzuki bean consumption and note the variety or origin (if known) to explore how different types of beans affect their nutrition and digestion over time
  • Users interested in heritage foods could use the app to experiment with adding adzuki beans to their diet in different ways—soups, side dishes, or traditional recipes—and track how they feel and their energy levels
  • For those interested in legume diversity, track consumption of different bean varieties over weeks and months to ensure dietary variety and monitor digestive comfort, energy levels, and overall wellness

This article describes archaeological and historical research about the origins of adzuki bean farming. It is not medical advice and should not be used to make health or dietary decisions. If you have questions about adzuki beans as food or nutrition, please consult with a healthcare provider or registered dietitian. The findings presented are historical in nature and do not constitute recommendations for personal health or wellness.