Serum lipid profiles in Japanese women and men during consumption of walnuts

Eur J Clin Nutr. 2002 Jul;56(7):629-37. doi: 10.1038/sj.ejcn.1601400.


Objective: To determine the serum cholesterol, apolipoproteins and LDL oxidizability in young Japanese women and men during walnut consumption and to evaluate its active principle.

Design: Experimental study with a randomized design.

Subjects: Twenty healthy women and 20 healthy men.

Interventions: Subjects were randomly assigned to consume each of two mixed natural diets for 4 weeks in a cross-over design. Reference and walnut diets were designed and the walnut diet had 12.5% of the energy derived from walnuts (44-58 g/day).

Results: The total cholesterol and serum apolipoprotein B concentrations, and the ratio of LDL cholesterol to HDL cholesterol was significantly lowered in women and men when fed on the walnut diet, than when on the reference diet (P<or=0.05). The LDL cholesterol concentration was significantly lowered in women on the walnut diet (0.22 mmol/l, P=0.0008), whereas this decrease was not significant in men (0.18 mmol/l, P=0.078). The most prominent change in the fatty acid composition of the cholesteryl esters from serum after the walnut diet was an elevation of alpha-linolenic acid in women (76%, P<0.001) and men (107%, P<0.001). This elevation was negatively correlated to the change in LDL cholesterol in women (r=0.496, P=0.019) and men (r=0.326, P=0.138). The LDL oxidizability in women was not influenced by the diets (P=0.19).

Conclusions: alpha-Linolenic acid in the walnut diet appears to be responsible for the lowering of LDL cholesterol in women.

Sponsorship: Kyushu University (Fukuoka, Japan) and the California Walnut Commission (California, USA).

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Apolipoproteins B / blood*
  • Cholesterol / blood*
  • Cholesterol Esters / chemistry
  • Cholesterol, HDL / blood
  • Cholesterol, LDL / blood
  • Cholesterol, LDL / metabolism
  • Cross-Over Studies
  • Female
  • Humans
  • Japan
  • Linoleic Acid / metabolism
  • Male
  • Nuts*
  • Oxidation-Reduction
  • Sex Factors
  • Single-Blind Method
  • Triglycerides / blood


  • Apolipoproteins B
  • Cholesterol Esters
  • Cholesterol, HDL
  • Cholesterol, LDL
  • Triglycerides
  • Cholesterol
  • Linoleic Acid