Levels of the n-3 fatty acid eicosapentaenoic acid in addition to those of alpha linolenic acid are significantly raised in blood lipids by the intake of four walnuts a day in humans.
OBJECTIVE
Ingestion of alpha linolenic acid (ALA), with the richest source among dry fruits such as walnuts, is associated with cardiovascular prevention. The aim of this study was to selectively evaluate the effects of moderate walnut consumption on the levels of ALA and its metabolic derivatives in human blood.


RESULTS
After a 2-week run-in period, 10 volunteers consumed 4 walnuts per day (in addition to their habitual diet) for 3 weeks. Fatty acid profiles, with special attention to levels of ALA and long chain polyunsaturated fatty acids (LC-PUFA), were assessed in blood drops collected from fingertips. The data indicate that the administration of a few walnuts a day for 3 weeks significantly increases blood levels, not only of ALA (from 0.23+/-0.07 SD to 0.47+/-0.13 SD), but also of its longer chain derivative eicosapentaenoic acids (EPA) (from 0.23+/-0.37 to 0.82+/-0.41) with levels remaining elevated over basal values after washout.


CONCLUSIONS
The findings of this pilot study indicate that plant ALA in appropriate food items favourably affects the n-3 LC-PUFA status.
Marangoni
Franca
F
Department of Pharmacological Sciences, University of Milan, Milan, Italy. franca.marangoni@unimi.it
Colombo
Claudio
C
Martiello
Antonella
A
Poli
Andrea
A
Paoletti
Rodolfo
R
Galli
Claudio
C
D000328:Adult; D038441:Diet, Mediterranean; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage* / Q000032:analysis; D015118:Eicosapentaenoic Acid / Q000032:analysis / Q000097:blood*; D005260:Female; D006801:Humans; D031324:Juglans; D008297:Male; D015596:Nutrition Assessment; D009754:Nuts / Q000737:chemistry; D010865:Pilot Projects; D011795:Surveys and Questionnaires; D017962:alpha-Linolenic Acid / Q000032:analysis / Q000097:blood*
D004042:Dietary Fats, Unsaturated; D017962:alpha-Linolenic Acid; D015118:Eicosapentaenoic Acid