Table 1.

Short and long-term recommendations for addressing race and ethnicity in future DNAm research

Short-term recommendations

Intrinsic factors: Self-identified race and ethnicity 1. Determine the theoretical and/or biological reasoning for including race and ethnicity in the purpose of the research 2. Clearly define and describe how race and ethnicity are measured and conceptualized, and avoid the interchangeable use of these terms Intrinsic factor: Genetic ancestry 3. Describe genetic ancestry along a continuum, and racial derived groupings or ethnicity categories or continent-level ancestry clusters should not be used as proxies for genetic ancestry 4. Account for population structure, specifically genetic heterogeneity, when possible and appropriate based on the goals of the research. This may include stratification, interaction, or adjusting the model for genetic covariates (DNAm-based tools may be used to account for population stratification if genotype data are not available.) Intrinsic factors: Genetic variations 5. Examine the effects of genetic variants (Use mQTL databases and/or plot the distribution of CpGs to identify potential mQTLs if genotype data are not available.) 6. Acknowledge limitations of currently available data and tools Intrinsic & extrinsic factors 7. Consider interactions between genes and environment as well as between culture and environment 8. Leverage interdisciplinary collaborations and engage local stakeholders in the research process to consider relevant intrinsic and extrinsic factors

Long-term recommendations

Extrinsic factors 1. Expand metadata collection to structural and sociocultural factors relevant to race and ethnicity by adopting interdisciplinary perspectives 2. Extend research to examine more associations within the same individual over time, such as in the context of interventions and longitudinal designs 3. Support and fund multidisciplinary and global teams to collect data and interpret results in diverse populations sensitively and appropriately Intrinsic factors 4. Improve methodology for characterizing genetic heterogeneity in multiracial and multiethnic individuals 5. Increase diversity of genetic ancestry and racial and ethnic groups in DNAm research and mQTL databases 6. Update DNAm tools to include more genetic, racial, and ethnic diversity in their training and testing sets Intrinsic and extrinsic factors 7. Compare individuals with different experiences or environments within the same genetic ancestry, including different ethnic and racial identities