High risk and uncertainty in the markets cause volatility to increase. Specifically, the increase in price fluctuations in stock markets may cause investors to engage in shorter-term and more speculative transactions. This situation manifests itself as sudden decreases or increases in stock indexes. On the other hand, investors with reduced risk appetite tend to avoid high-risk investments such as technology stocks and turn to more defensive sectors. For example, companies operating in sectors such as healthcare, essential consumption, and public services may attract more investor attention during periods of risk and uncertainty. In this context, analyzing the effects of risk and uncertainty indexes on sectoral stock index values is a noteworthy subject. This study aims to investigate whether there is a causality relationship from the Global Economic Policy Uncertainty (EPU) and Oil Volatility (OVX) indices to the Borsa Istanbul (BIST) Food and Beverage (XGIDA) index by employing the Granger causality test, the Breitung-Candelon frequency domain causality test and the time-varying bootstrap causality test in the frequency domain, respectively. The analysis spanning from June 2007 to September 2024 revealed a causality from the EPU and OVX indices to the XGIDA index, which differed according to the applied tests. The Granger causality test finding indicates a general causal relationship from the EPU index to the XGIDA index over the examined period. The Breitung-Candelon frequency domain causality test, which examines frequency domain relationships, shows only a long-term causality from the EPU index to the XGIDA index. However, the time-varying bootstrap causality test findings in the frequency domain reveal both long-term and short-term causal relationships from the EPU and OVX indices to the XGIDA index, with these relationships changing over time. In other words, the time-varying bootstrap causality test in the frequency domain indicates that the EPU and OVX indices have nonpermanently unstable effects on the XGIDA index.