Serum sterol responses to increasing plant sterol intake from natural foods in the Mediterranean diet.
BACKGROUND
Phytosterols in natural foods are thought to inhibit cholesterol absorption. The Mediterranean diet is rich in phytosterol-containing plant foods.


OBJECTIVE
To assess whether increasing phytosterol intake from natural foods was associated with a cholesterol-lowering effect in a substudy of a randomized trial of nutritional intervention with Mediterranean diets for primary cardiovascular prevention (PREDIMED study).


METHODS
One hundred and six high cardiovascular risk subjects assigned to two Mediterranean diets supplemented with virgin olive oil (VOO) or nuts, which are phytosterol-rich foods, or advice on a low-fat diet. Outcomes were 1-year changes in nutrient intake and serum levels of lipids and non-cholesterol sterols.


RESULTS
Average phytosterol intake increased by 76, 158 and 15 mg/day in participants assigned VOO, nuts and low-fat diets, respectively. Compared to participants in the low-fat diet group, changes in outcome variables were observed only in those in the Mediterranean diet with nuts group, with increases in intake of fibre, polyunsaturated fatty acids and phytosterols (P < 0.020, all) and significant (P < 0.05) reductions of LDL-cholesterol (0.27 mmol/l or 8.3%) and the LDL/HDL-cholesterol ratio (0.29 mmol/l or 11.5%). Variations in saturated fat, cholesterol or fibre intake were unrelated to LDL-cholesterol changes. In the whole group, changes in serum sitosterol-to-cholesterol, which reflect those of dietary phytosterol intake and absorption, correlated inversely to LDL-cholesterol changes (r = -0.256; P = 0.008). In multivariate analyses, baseline LDL-cholesterol, increases in serum sitosterol ratios and statin use were independently associated with LDL-cholesterol reductions.


CONCLUSIONS
Small amounts of phytosterols in natural foods appear to be bioactive in cholesterol lowering.
Lipid Clinic, Endocrinology and Nutrition Service, Institut d'Investigacions Biomèdiques Ausgust Pi Sunyer (IDIBAPS), Hospital Clínic, Barcelona, Spain.
Verónica
V
Escurriol
Montserrat
M
Cofán
Mercè
M
Serra
Mónica
M
Bulló
Josep
J
Basora
Jordi
J
Salas-Salvadó
Dolores
D
Corella
Itziar
I
Zazpe
Miguel A
MA
Martínez-González
Valentina
V
Ruiz-Gutiérrez
Ramón
R
Estruch
Emilio
E
Ros
D000368:Aged; D000924:Anticholesteremic Agents / Q000008:administration & dosage*; D002318:Cardiovascular Diseases / Q000517:prevention & control; D002784:Cholesterol / Q000031:analogs & derivatives / Q000097:blood*; D018752:Diet, Fat-Restricted; D038441:Diet, Mediterranean; D004041:Dietary Fats / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D005502:Food; D005504:Food Analysis; D006801:Humans; D007536:Isomerism; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009754:Nuts / Q000737:chemistry; D031658:Olea / Q000737:chemistry; D010353:Patient Education as Topic; D010840:Phytosterols / Q000008:administration & dosage* / Q000032:analysis / Q000097:blood; D010945:Plants, Edible; D012307:Risk Factors; D012855:Sitosterols / Q000097:blood; D013223:Statistics as Topic; D011795:Surveys and Questionnaires
D000924:Anticholesteremic Agents; D004041:Dietary Fats; D008055:Lipids; D010840:Phytosterols; D012855:Sitosterols; C021273:campesterol; C001521:lathosterol; D002784:Cholesterol