Long-term fasting improves lipoprotein-associated atherogenic risk in humans.

Purpose: Dyslipidemia is a major health concern associated with an increased risk of cardiovascular mortality. Long-term fasting (LF) has been shown to improve plasma lipid profile. We performed an in-depth investigation of lipoprotein composition.

Methods: This observational study included 40 volunteers (50% men, aged 32-65 years), who underwent a medically supervised fast of 14 days (250 kcal/day). Changes in lipid and lipoprotein levels, as well as in lipoprotein subclasses and particles, were measured by ultracentrifugation and nuclear magnetic resonance (NMR) at baseline, and after 7 and 14 fasting days.

Results: The largest changes were found after 14 fasting days. There were significant reductions in triglycerides (TG, - 0.35 ± 0.1 mmol/L), very low-density lipoprotein (VLDL)-TG (- 0.46 ± 0.08 mmol/L), VLDL-cholesterol (VLDL-C, - 0.16 ± 0.03 mmol/L) and low-density lipoprotein (LDL)-C (- 0.72 ± 0.14 mmol/L). Analysis of LDL subclasses showed a significant decrease in LDL1-C (- 0.16 ± 0.05 mmol/L), LDL2-C (- 0.30 ± 0.06 mmol/L) and LDL3-C (- 0.27 ± 0.05 mmol/L). NMR spectroscopy showed a significant reduction in large VLDL particles (- 5.18 ± 1.26 nmol/L), as well as large (- 244.13 ± 39.45 nmol/L) and small LDL particles (- 38.45 ± 44.04 nmol/L). A significant decrease in high-density lipoprotein (HDL)-C (- 0.16 ± 0.04 mmol/L) was observed. By contrast, the concentration in large HDL particles was significantly raised. Apolipoprotein A1 decreased significantly whereas apolipoprotein B, lipoprotein(a), fibrinogen and high-sensitivity C-reactive protein were unchanged.

Conclusion: Our results suggest that LF improves lipoprotein levels and lipoprotein subclasses and ameliorates the lipoprotein-associated atherogenic risk profile, suggesting a reduction in the cardiovascular risk linked to dyslipidemia.

Trial Registration: Study registration number: DRKS-ID: DRKS00010111 Date of registration: 03/06/2016 "retrospectively registered".