Aims: Energy-rich dietary patterns (DPs) have been shown to reduce risk of malnutrition in cancer. Whether these DPs improve survival has not been investigated. This study prospectively examined associations between DPs linked to a lower risk of malnutrition with risk of all-cause and cancer-specific mortality.
Methods: 2,415 UK Biobank participants with a previous cancer diagnosis (mean±SD, 7.1±6.3 years since diagnosis) aged 59.7±7.1 years (60.7% female) were included. Dietary intake was estimated using the Oxford WebQ 24-hour dietary assessment. Dietary patterns (‘high oily fish and nuts’ and ‘low oily fish’) were previously identified using reduced rank regression with protein (g/kg/day), polyunsaturated fatty acids (g/day) and vitamin D (ug/day) as response variables. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95%CI of all-cause and cancer-specific mortality. Nonlinear relationships were examined using restricted cubic splines. Models were adjusted for demographic and health characteristics.
Results: Deaths due to all-cause (n=305) and cancer (n=249) were identified during a median of 10.4 (IQR: 10.2–10.8) years follow-up. No DPs were associated with all-cause or cancer-specific mortality, with the exception of a significant U-shaped association between the energy-rich ‘high oily fish and nuts’ DP and all-cause mortality. Low and high adherence was associated with an increased risk of all-cause mortality. Moderate adherence, at the sample mean, had no impact on all-cause mortality.
Conclusions: Energy rich DP’s that were protective against malnutrition did not improve survival in adults with a previous cancer diagnosis. However, moderate adherence to the ‘high oily fish and nuts’ DP had no significant impact on risk of mortality. This may be due to the heterogeneous sample resulting from a long time period since diagnosis. Further investigation is required to assess the efficacy of the ‘high oily fish and nuts’ DP in the acute treatment period when malnutrition is most prevalent.