Healthy low-carb, low-fat diets help prevent all-cause death

Healthy scores in low-carbohydrate (LCD) and low-fat diets (LFD) appear to reduce the risk of all-cause mortality, while unhealthy scores are predictive of an increased risk, among people with prediabetes, a study has shown.

A total of 9,793 adults with prediabetes from the NHANES 1999‒2014 were included in this study. The authors linked mortality status to National Death Index mortality data through 31 December 2015. They estimated overall, unhealthy, and healthy LCD and LFD scores based on the percentages of energy from total and subtypes of carbohydrate, fat, and protein. Finally, hazard ratios (HRs) and 95 percent confidence intervals (CIs) were calculated using Cox proportional hazards regression models.

Higher healthy LCD score correlated with favourable insulin, blood glucose, HOMA-IR, C-reactive protein (CRP), and blood lipids, while higher healthy LFD score correlated with lower blood glucose and CRP at baseline (p_trend<0.05 for all).

Overall, 1,352 deaths occurred during 72,054 person-years of follow-up. The adjusted HRs of all-cause mortality per 10-percentile increase in dietary scores were as follows: 0.88 (95 percent CI, 0.80‒0.96) for healthy LCD score (p=0.003), 0.85 (95 percent CI, 0.78‒0.93) for healthy LFD score (p<0.001), 1.09 (95 percent CI, 0.99‒1.21) for unhealthy LCD score (p=0.08), and 1.11 (95 percent CI, 1.00‒1.22) for unhealthy LFD score (p=0.05).

Of note, isocalorically replacing 3 percent to 5 percent energy of low-quality carbohydrate or saturated fat with high-quality carbohydrate, plant-based protein, or unsaturated fat resulted in a 14 percent to 37 percent lower all-cause mortality.