Effects of walnut consumption on plasma fatty acids and lipoproteins in combined hyperlipidemia.
BACKGROUND
Epidemiologic studies show an inverse relation between nut consumption and coronary heart disease.


OBJECTIVE
We determined the effects of walnut intake on plasma fatty acids, lipoproteins, and lipoprotein subclasses in patients with combined hyperlipidemia.


METHODS
Participants sequentially adhered to the following diets: 1) a habitual diet (HD), 2) a habitual diet plus walnuts (HD+W), 3) a low-fat diet (LFD), and 4) a low-fat diet plus walnuts (LFD+W).


RESULTS
In 13 postmenopausal women and 5 men ( +/- SD age 60 +/- 8 y), walnut supplementation did not increase body weight despite increased energy intake and the LFD caused weight loss (1.3 +/- 0.5 kg; P < 0.01). When comparing the HD with the HD+W, linoleic acid concentrations increased from 29.94 +/- 1.14% to 36.85 +/- 1.13% and alpha-linolenic acid concentrations increased from 0.78 +/- 0.04% to 1.56 +/- 0.11%. During the LFD+W, plasma total cholesterol concentrations decreased by 0.58 +/- 0.16 mmol/L when compared with the HD and by 0.46 +/- 0.14 mmol/L when compared with the LFD. LDL-cholesterol concentrations decreased by 0.46 +/- 0.15 mmol/L when compared with the LFD. Measurements of lipoprotein subclasses and particle size suggested that walnut supplementation lowered cholesterol preferentially in small LDL (46.1 +/- 1.9% compared with 33.4 +/- 4.3%, HD compared with HD+W, respectively; P < 0.01). HDL-cholesterol concentrations decreased from 1.27 +/- 0.07 mmol/L during the HD to 1.14 +/- 0.07 mmol/L during the HD+W and to 1.11 +/- 0.08 mmol/L during the LFD. The decrease was seen primarily in the large HDL particles.


CONCLUSIONS
Walnut supplementation may beneficially alter lipid distribution among various lipoprotein subclasses even when total plasma lipids do not change. This may be an additional mechanism underlying the antiatherogenic properties of nut intake.
Almario
R U
RU
Department of Internal Medicine, Division of Endocrinology and Metabolism, School of Medicine, University of California, Davis, USA.
Vonghavaravat
V
V
Wong
R
R
Kasim-Karakas
S E
SE
D003327:Coronary Disease / Q000517:prevention & control; D015930:Diet Records; D018752:Diet, Fat-Restricted; D005227:Fatty Acids / Q000097:blood*; D005260:Female; D006801:Humans; D006950:Hyperlipidemia, Familial Combined / Q000097:blood / Q000178:diet therapy*; D019787:Linoleic Acid / Q000097:blood; D008075:Lipoproteins, HDL / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009754:Nuts / Q000627:therapeutic use*; D010316:Particle Size; D008517:Phytotherapy; D017962:alpha-Linolenic Acid / Q000097:blood
D005227:Fatty Acids; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D017962:alpha-Linolenic Acid; D019787:Linoleic Acid