Interplay of Walnut Consumption, Changes in Circulating miRNAs and Reduction in LDL-Cholesterol in Elders

Nutrients. 2022 Apr 1;14(7):1473. doi: 10.3390/nu14071473.


The mechanisms underlying the lipid-lowering effect of nuts remain elusive. This study explores whether one-year supplementation with walnuts decreases LDL-cholesterol (LDL-C) by affecting the expression of circulating microRNAs (c-miRNA). In this sub-study of the Walnuts and Healthy Aging (WAHA) trial, we obtained fasting serum at baseline and at 1 year from 330 free-living participants (63-79 year, 68% women), allocated into a control group (CG, abstinence from walnuts, n = 164) and a walnut group (WG, 15% of daily energy as walnuts, ~30-60 g/d, n = 166). Participants in the WG showed a 1 year decrease in LDL-C (-9.07, (95% confidence interval: -12.87; -5.73) mg/dL; p = 0.010 versus changes in the CG). We conducted a miRNA array in eight randomly selected participants in the WG who decreased in LDL-C. This yielded 53 c-miRNAs with statistically significant changes, 27 of which survived the correction for multiple testing. When validating them in the full population, statistical significance lasted for hsa-miR-551a, being upregulated in the WG. In mediation analysis, the change in hsa-miR-551a was unrelated to LDL-C decrease. Long-term supplementation with walnuts decreased LDL-C independently of the changes in c-miRNA. The hsa-miR-551a upregulation, which has been linked to a reduced cell migration and invasion in several carcinomas, suggests a novel mechanism of walnuts in cancer risk.

Keywords: alpha-linolenic acid; biomarkers; cholesterol; lipid metabolism; nuts.

Publication types

  • Clinical Trial

MeSH terms

  • Aged
  • Cholesterol, LDL*
  • Circulating MicroRNA*
  • Female
  • Humans
  • Juglans*
  • Male
  • MicroRNAs / genetics
  • Middle Aged


  • Cholesterol, LDL
  • Circulating MicroRNA
  • MicroRNAs