Adequate Copper Intake Linked to Lower Risk of Chronic and Diabetic Kidney Disease: NHANES Study
China: A new study published in Frontiers in Endocrinology suggests that maintaining sufficient copper intake could play a protective role against chronic kidney disease (CKD) and diabetic kidney disease (DKD).
Shasha Hu from the Department of Nephrology, Zibo Central Hospital, Zibo, China, and colleagues aimed to clarify the unclear relationship between dietary copper intake and kidney-related disorders.
The research analyzed data from the U.S. National Health and Nutrition Examination Survey (NHANES) spanning 2011 to 2018. Using a nationally representative dataset, the researchers evaluated 16,948 participants, which included 3,319 individuals diagnosed with CKD and 13,629 without the condition.
For statistical analysis, the team used a complex survey design–adjusted weighted t-tests and chi-square tests to compare variables. Univariate and multivariate logistic regression analyses were conducted to assess the independent relationship between copper intake and CKD/DKD, while restricted cubic spline (RCS) models were applied to evaluate potential non-linear associations.
The study led to the following notable findings:
- The analysis demonstrated a clear inverse relationship between copper intake and the risk of kidney disease.
- Participants consuming up to 1.47 mg of copper per day had a 49% lower risk of developing CKD.
- Those with copper intake up to 0.98 mg per day showed a 60% lower likelihood of developing DKD (OR 0.40).
- The inverse association between copper intake and kidney disease risk was consistent across all subgroups examined.
- Multivariate regression analysis revealed a negative correlation between copper intake and both CKD (OR > 0.80) and DKD.
- Restricted Cubic Spline (RCS) analysis suggested a non-linear association, indicating that the protective effect of copper may be confined to certain intake ranges.
The authors emphasized that while copper is an essential trace mineral involved in various physiological processes, excessive or insufficient intake can disrupt metabolic balance. Their findings indicate that maintaining optimal copper levels might support kidney function and reduce disease risk among adults.
However, the researchers cautioned that the study’s cross-sectional design limits the ability to establish cause-and-effect relationships. They also noted that copper intake was assessed using 24-hour dietary recall methods, which can introduce recall bias and may not capture long-term consumption patterns. Despite adjusting for multiple confounding factors, residual confounding due to unmeasured variables, such as other dietary components or lifestyle factors, cannot be entirely excluded.
Moreover, since the study population was drawn from the U.S., the generalizability of the findings to other populations or regions requires further investigation.
"The large-scale NHANES-based analysis found that adequate copper intake was significantly and inversely associated with the risk of CKD and DKD within specific thresholds. The results emphasize the potential role of balanced trace mineral nutrition in kidney health, paving the way for future longitudinal studies to confirm these associations and define optimal dietary intake levels for prevention," the authors concluded.
Reference:
Hu, S., Tian, X., Wang, Z., & Li, M. (2025). The relationship between copper intake and chronic kidney disease/diabetic kidney disease: Insights from NHANES data (2011-2018). Frontiers in Endocrinology, 16, 1674439. https://doi.org/10.3389/fendo.2025.1674439
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