Effect of 1-y oral supplementation with vitaminized olive oil on platelets from healthy postmenopausal women.

OBJECTIVE: Olive oil is the main fat source in the Mediterranean diet and shows a protective role against aging and related diseases. Osteoporosis represents a serious health problem worldwide and is associated with an increased risk for fractures and mortality. Nutrition should be part of bone disease prevention strategies, especially in light of the aging population and the effect of diet on bone health. The aim of this study was to investigate whether oral supplementation with extra virgin olive oil (VOO) enriched with vitamins D3, K1, and B6 (VitVOO) is able to modify some physicochemical and functional plasma membrane properties and nitrosative stress markers status. METHODS: In this single-center, randomized placebo-controlled trial, 60 postmenopausal women were administered either VitVOO or placebo (PlaVOO). After 1 y of oral supplementation, platelet membrane fluidity changes, Na+/K+-ATPase activity, serum nitric oxide, and peroxynitrite levels were determined in participants. RESULTS: After 1 y (time 1), women taking VitVOO showed lower nitric oxide levels than those taking PlaVOO; the same trend was found for peroxynitrite levels. As far as membrane fluidity was concerned, a significant decrease in anisotropy of diphenylhexatriene and trimethylammonium-diphenylhexatriene at time 1 in VitVOO participants compared with PlaVOO was found. Finally, Na+/K+-ATPase activity showed a significant increase after VitVOO supplementation. CONCLUSION: The supplementation of VitVOO into the diet of postmenopausal women could represent a proper tool for platelet function and a useful strategy against nitrosative stress and related diseases, thus confirming the antioxidant role played by the added vitamins.

Effect of 1-year dietary supplementation with vitaminized olive oil on markers of bone turnover and oxidative stress in healthy post-menopausal women.

Osteoporosis represents a serious health problem worldwide associated with an increased risk of fractures and mortality. Nutrition should form part of bone disease prevention strategies, especially in the light of the population ageing and the diet effect on bone health. Thus the study aimed at verifying whether 1 year of oral supplementation with either extra virgin olive oil (VOO) enriched with vitamins D3, K1 and B6 (VitVOO) or VOO used as placebo (PlaVOO) is able to modify some bone turnover and oxidative stress markers. Bone mineral density (BMD) was assessed in 60 healthy post-menopausal women together with the bone vitamin K status by measuring undercarboxylated osteocalcine (ucOC) plasma levels, the ratio between ucOC and carboxylated osteocalcine (UCR) and the relations with oxidative stress markers. After 1 year (T 1), subjects taking VitVOO showed lower ucOC levels than those taking PlaVOO; the same trend was found for UCR. As far as BMD is concerned, a significant increase in T-score at T 1 in VitVOO subjects compared to PlaVOO was found. All oxidative stress markers as thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes showed a significant reduction after VitVOO supplementation, whilst plasma total antioxidant capacity values was significantly increased in VitVOO group compared to PlaVOO group at T 1. It might be suggested that the use of VitVOO in the diet of post-menopausal women could represent a proper tool for bone protection and a useful strategy against oxidative stress and related diseases, thus confirming the antioxidant role played by the added vitamins.

Plasma lipids and physicochemical properties of the erythrocyte plasma membrane throughout pregnancy.

BACKGROUND: The physiopathological relevance of plasma lipid concentrations is supported by the observation that they might affect the physicochemical properties of the plasma membrane of circulating cells and might be crucial in the pathological conditions complicating pregnancy. METHODS: Plasma and erythrocyte membrane lipid composition, membrane fluidity and function [membrane-bound enzyme sodium/potassium adenosine triphosphatase (Na+/K+-ATPase) activity] were studied in 24 healthy women in the nonpregnant condition and at 12, 24 and 38 weeks' gestation. RESULTS: The plasma showed an increase in total and high density lipoprotein (HDL) cholesterol, triglyceride (TG) and phospholipid (PL) levels. In the erythrocyte membrane we found the cholesterol/phospholipid (C/PL) ratio increased and the saturated to unsaturated fatty acid (FA) ratio (Sat/Unsat) significantly reduced; fluorescence polarization showed an initial increase during pregnancy and a progressive decrease afterwards; Na+/K+-ATPase activity was progressively reduced. CONCLUSIONS: A generalized alteration in the composition and function of the maternal erythrocyte membrane is present during a physiological pregnancy, and these modifications may involve a more complex physiopathogenetic mechanism.