Increased intake of fruit and vegetables and a low-fat diet, with and without low-fat plant sterol-enriched spread consumption: effects on plasma lipoprotein and carotenoid metabolism.
BACKGROUND
Regular intake of plant sterol (phytosterol)-enriched foods enhances the cholesterol lowering effect of diets. One side effect associated with plant sterol consumption is a modest reduction in plasma carotenoid concentrations. This study investigated the effect of consuming a low-fat National Cholesterol Education Programme (NCEP) Step 1 diet, including a low-fat plant sterol ester (PSE)-enriched spread on cholesterol metabolism to determine if specific dietary advice to increase daily fruit and vegetable intake could prevent reduced plasma carotenoid concentrations.


METHODS
In this randomised, crossover double-blind trial, 48 hypercholesterolaemic men received 21 g day(-1) of a low-fat PSE-enriched spread or placebo for 3 weeks, interrupted by 3 weeks washout. Individuals also adhered to a NCEP Step 1 diet and repeated 3-day food diaries monitored adherence. Specific advice was provided to increase dietary fruit and vegetable intakes. Fasting blood samples were collected at pre- and post-intervention for lipoprotein and carotenoid analysis.


RESULTS
Plasma total and low-density lipoprotein (LDL) cholesterol concentrations were significantly (P <0.05) reduced, by 4.6 and 7.1%, respectively, after the PSE-enriched low-fat spread. Plasma apo B concentrations were significantly (P <0.0005) lower after the PSE spread. PSE consumption was also associated with significantly (P <0.05) lower total plasma beta-carotene concentrations, but this change was not significant after lipid standardisation. PSE consumption had no effect on retinol, alpha-carotene, gamma-tocopherol, alpha-tocopherol, lutein, zeaxanthin, beta-crypyoxanthin or lycopene concentrations.


CONCLUSIONS
Dietary advice to increase daily fruit and vegetable consumption may be effective in preventing a reduction in plasma carotenoid concentrations previously associated with PSE consumption. Further, PSE incorporated in a low-fat spread and consumed as part of a NCEP Step 1 diet are effective in reducing total and LDL cholesterol.
Colgan
H A
HA
Unit of Nutrition, Department of Clinical Medicine, Trinity Health Sciences Centre, St James's Hospital, Dublin, Ireland.
Floyd
S
S
Noone
E J
EJ
Gibney
M J
MJ
Roche
H M
HM
D000328:Adult; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D002338:Carotenoids / Q000097:blood* / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D018752:Diet, Fat-Restricted; D004311:Double-Blind Method; D005260:Female; D005638:Fruit; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000178:diet therapy*; D008297:Male; D008383:Margarine; D008875:Middle Aged; D010840:Phytosterols / Q000008:administration & dosage* / Q000009:adverse effects; D016896:Treatment Outcome; D014675:Vegetables
D000975:Antioxidants; D008078:Cholesterol, LDL; D010840:Phytosterols; D002338:Carotenoids; D008383:Margarine; D002784:Cholesterol