The impact of improved crop varieties on household food security, income and nutrition: a systematic review

This study undertakes a systematic review of the effects of improved crop varieties on household food security, income, and nutrition. Following PRISMA 2020 guidelines, a search of major databases was conducted for studies published between 1990 and 2025. A total of 936 records were identified. After duplicate removal, 868 were screened, and 76 full-text studies were assed for eligibility. Ultimately, 17 studies were included in the final synthesis. These studies covered a range of cereal, legume, and root crops.. The findings consistently show that adopting improved varieties significantly enhanced household food security by increasing yields, improving dietary diversity, and reducing food insecurity. Positive income effects were observed through higher annual household income, increased crop productivity, and enhanced food consumption. The nutrition outcomes were also positive, although they varied across studies, with numerous studies demonstrating improvements in dietary diversity but limited impact on household nutritional status. The results indicate that most studies focused on legume and cereal crops, with minimal emphasis on root and tuber crops, and that few studies concurrently evaluated all three welfare outcomes. Future research should employ integrated welfare frameworks and expand crop coverage to strengthen the evidence base for inclusive and nutrition-sensitive agricultural development.